From b643a0acbed7518c6fa0ddb76f60db8fafb86e27 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Mon, 22 Jun 2026 08:55:53 -0400
Subject: [PATCH 01/18] feat(stop_and_print): print string_t in pure procs

This commit adds a pure stop_and_print subroutine and a
corresponding unit test.  The new subroutine facilitates printing
string_t objects, including the results of string_t expressions,
during error termination.

Example Usage:

call stop_and_print( "array = " // string_t( [1,2,3,4] ) )
---
 src/julienne/julienne_stop_and_print_m.F90 | 20 ++++++++++++
 src/julienne_m.F90                         |  1 +
 test/test_stop_and_print.F90               | 38 ++++++++++++++++++++++
 3 files changed, 59 insertions(+)
 create mode 100644 src/julienne/julienne_stop_and_print_m.F90
 create mode 100644 test/test_stop_and_print.F90

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
new file mode 100644
index 000000000..19d358b9a
--- /dev/null
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -0,0 +1,20 @@
+! Copyright (c), The Regents of the University of California and Sourcery Institute
+! Terms of use are as specified in LICENSE.txt
+
+module julienne_stop_and_print_m
+  !! Define a pure subroutine subroutine that prints string_t objects/arrays
+  use julienne_string_m, only : string_t
+  implicit none
+  
+  private
+  public :: stop_and_print
+
+contains
+
+  pure subroutine stop_and_print(message)
+    implicit none
+    type(string_t), intent(in) :: message
+    error stop message%string()
+  end subroutine
+  
+end module
diff --git a/src/julienne_m.F90 b/src/julienne_m.F90
index abff7c3d2..1825a9343 100644
--- a/src/julienne_m.F90
+++ b/src/julienne_m.F90
@@ -9,6 +9,7 @@ module julienne_m
   use julienne_file_m, only : file_t
   use julienne_formats_m, only : separated_values, csv
   use julienne_github_ci_m, only : github_ci
+  use julienne_stop_and_print_m, only : stop_and_print
   use julienne_string_m, only : string_t, array_of_strings &
     ,operator(.cat.) &
     ,operator(.csv.) &
diff --git a/test/test_stop_and_print.F90 b/test/test_stop_and_print.F90
new file mode 100644
index 000000000..194eab78c
--- /dev/null
+++ b/test/test_stop_and_print.F90
@@ -0,0 +1,38 @@
+! Copyright (c) 2024-2025, The Regents of the University of California and Sourcery Institute
+! Terms of use are as specified in LICENSE.txt
+
+#include "julienne-assert-macros.h"
+#include "language-support.F90"
+
+program stop_and_print_in_pure_procedure
+  !! Conditionally test printing via error termination inside a pure procedure
+  use julienne_m, only : command_line_t, string_t, operator(.csv.), stop_and_print
+  implicit none
+
+#if HAVE_MULTI_IMAGE_SUPPORT
+  associate(command_line => command_line_t(), me => this_image())
+#else
+  associate(command_line => command_line_t(), me => 1)
+#endif
+    if (.not. command_line%argument_present([character(len=len("--help"))::"--help","-h"])) then
+#if TEST_INTENTIONAL_FAILURE && ASSERTIONS
+      if (me==1) print '(a)', new_line('') // 'Test the intentional failure of an idiomatic assertion: ' // new_line('')
+      call pure_subroutine
+#else
+      if (me==1) print '(a)',  &
+           new_line('') // &
+           'Skipping the test in ' // __FILE__ // '.' // new_line('') // &
+           'Add the following to your fpm command to test the stop_and_print: --flag "-DASSERTIONS -DTEST_INTENTIONAL_FAILURE"' // &
+           new_line('')
+#endif
+    end if
+  end associate
+
+contains
+
+  pure subroutine pure_subroutine
+    integer, parameter :: array(*) = [1,2,3,4]
+    call stop_and_print("array = " // .csv. string_t(array))
+  end subroutine
+
+end program

From 274bfd64477d525d2fb29a42604d4a842f62074e Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Wed, 24 Jun 2026 21:39:28 -0600
Subject: [PATCH 02/18] feat: mk stop_and_print generic

---
 src/julienne/julienne_stop_and_print_m.F90 | 89 +++++++++++++++++++++-
 1 file changed, 87 insertions(+), 2 deletions(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index 19d358b9a..ca4333f5f 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -8,13 +8,98 @@ module julienne_stop_and_print_m
   
   private
   public :: stop_and_print
+  
+  interface stop_and_print
+    module procedure print_string
+    module procedure print_header_and_data
+  end interface
+
+contains 
 
-contains
 
-  pure subroutine stop_and_print(message)
+  pure subroutine print_string(message)
     implicit none
     type(string_t), intent(in) :: message
     error stop message%string()
   end subroutine
+
+  pure subroutine print_header_and_data(header, data)
+    implicit none
+    character(len=*), intent(in) :: header
+    class(*), intent(in) :: data
+    error stop new_line('') // header // new_line('') // stringify(data)
+  end subroutine
+
+  pure function stringify(stuff) result(characters)
+    class(*), intent(in) :: stuff(..)
+    character(len=:), allocatable :: characters
+
+    type(string_t) stringy_stuff
+    integer row
+
+    select rank(stuff)
+      rank(0)
+        select type(stuff)
+          type is(character(len=*))
+            stringy_stuff = stuff
+          type is(complex)
+            stringy_stuff = string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff = string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff = string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(real)
+            stringy_stuff = string_t(stuff)
+            characters = stringy_stuff%string()
+          class default
+             error stop "stringify: unsupported type"
+        end select
+      rank(1)
+        select type(stuff)
+          type is(character(len=*))
+            stringy_stuff = .csv. string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(complex)
+            stringy_stuff = .csv. string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff = .csv. string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff = .csv. string_t(stuff)
+            characters = stringy_stuff%string()
+          type is(real)
+            stringy_stuff = .csv. string_t(stuff)
+            characters = stringy_stuff%string()
+          class default
+             error stop "stringify: unsupported type"
+        end select
+      rank(2)
+        select type(stuff)
+          type is(character(len=*))
+            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            characters = stringy_stuff%string()
+          type is(complex)
+            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            characters = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            characters = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            characters = stringy_stuff%string()
+          type is(real)
+            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            characters = stringy_stuff%string()
+          class default
+             error stop "stringify: unsupported type"
+        end select
+      rank default
+        error stop "stringify: unsupported rank"
+    end select
+  end function
   
 end module

From 7d77843996ffda006f5a118407c7f05e819ba041 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Fri, 26 Jun 2026 12:58:56 -0600
Subject: [PATCH 03/18] test(character_stop_code): 1D integer array passes

---
 src/julienne/julienne_stop_and_print_m.F90  | 47 ++++++++--------
 src/julienne_m.F90                          |  2 +-
 test/driver.F90                             |  3 +-
 test/modules/character_stop_code_test_m.F90 | 62 +++++++++++++++++++++
 4 files changed, 90 insertions(+), 24 deletions(-)
 create mode 100644 test/modules/character_stop_code_test_m.F90

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index ca4333f5f..bea27f169 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -3,11 +3,12 @@
 
 module julienne_stop_and_print_m
   !! Define a pure subroutine subroutine that prints string_t objects/arrays
-  use julienne_string_m, only : string_t
+  use julienne_string_m, only : string_t, operator(.csv.)
   implicit none
   
   private
   public :: stop_and_print
+  public :: character_stop_code
   
   interface stop_and_print
     module procedure print_string
@@ -27,12 +28,12 @@ pure subroutine print_header_and_data(header, data)
     implicit none
     character(len=*), intent(in) :: header
     class(*), intent(in) :: data
-    error stop new_line('') // header // new_line('') // stringify(data)
+    error stop new_line('') // header // new_line('') // character_stop_code(data)
   end subroutine
 
-  pure function stringify(stuff) result(characters)
+  pure function character_stop_code(stuff) result(stop_code)
     class(*), intent(in) :: stuff(..)
-    character(len=:), allocatable :: characters
+    character(len=:), allocatable :: stop_code
 
     type(string_t) stringy_stuff
     integer row
@@ -44,61 +45,63 @@ pure function stringify(stuff) result(characters)
             stringy_stuff = stuff
           type is(complex)
             stringy_stuff = string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(double precision)
             stringy_stuff = string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(integer)
             stringy_stuff = string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(real)
             stringy_stuff = string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           class default
-             error stop "stringify: unsupported type"
+             error stop "character_stop_code (in print_and_stop_s): unsupported type"
         end select
       rank(1)
         select type(stuff)
           type is(character(len=*))
             stringy_stuff = .csv. string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(complex)
             stringy_stuff = .csv. string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(double precision)
             stringy_stuff = .csv. string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(integer)
             stringy_stuff = .csv. string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(real)
             stringy_stuff = .csv. string_t(stuff)
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           class default
-             error stop "stringify: unsupported type"
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type"
         end select
       rank(2)
         select type(stuff)
           type is(character(len=*))
             stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(complex)
             stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(double precision)
             stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(integer)
             stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           type is(real)
             stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
-            characters = stringy_stuff%string()
+            stop_code = stringy_stuff%string()
           class default
-             error stop "stringify: unsupported type"
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type"
         end select
       rank default
-        error stop "stringify: unsupported rank"
+        associate(stop_code_rank => string_t(stop_code))
+          error stop "character_stop_code (in print_and_stop_s): unsupported stop-code rank: " //  stop_code_rank%string()
+        end associate
     end select
   end function
   
diff --git a/src/julienne_m.F90 b/src/julienne_m.F90
index 1825a9343..5b85b6325 100644
--- a/src/julienne_m.F90
+++ b/src/julienne_m.F90
@@ -9,7 +9,7 @@ module julienne_m
   use julienne_file_m, only : file_t
   use julienne_formats_m, only : separated_values, csv
   use julienne_github_ci_m, only : github_ci
-  use julienne_stop_and_print_m, only : stop_and_print
+  use julienne_stop_and_print_m, only : stop_and_print, character_stop_code
   use julienne_string_m, only : string_t, array_of_strings &
     ,operator(.cat.) &
     ,operator(.csv.) &
diff --git a/test/driver.F90 b/test/driver.F90
index 4aeb4c591..3112f44df 100644
--- a/test/driver.F90
+++ b/test/driver.F90
@@ -10,6 +10,7 @@ program test_suite_driver
   ! Modules containing test_t child types:
   use assert_test_m                    ,only :                   assert_test_t
   use bin_test_m                       ,only :                      bin_test_t
+  use character_stop_code_test_m       ,only :      character_stop_code_test_t
   use command_line_test_m              ,only :             command_line_test_t
   use formats_test_m                   ,only :                  formats_test_t
   use multi_image_test_m               ,only :              multi_image_test_t, multi_image_setup
@@ -17,7 +18,6 @@ program test_suite_driver
   use test_description_test_m          ,only :         test_description_test_t
   use test_diagnosis_test_m            ,only :           test_diagnosis_test_t
   use test_result_test_m               ,only :              test_result_test_t
-
   implicit none
 
   call multi_image_setup()
@@ -27,6 +27,7 @@ program test_suite_driver
   associate(test_harness => test_harness_t([           &
      test_fixture_t(                  assert_test_t()) &
     ,test_fixture_t(                     bin_test_t()) &
+    ,test_fixture_t(     character_stop_code_test_t()) &
     ,test_fixture_t(                 formats_test_t()) &
     ,test_fixture_t(             multi_image_test_t()) &
     ,test_fixture_t(                  string_test_t()) &
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
new file mode 100644
index 000000000..8efa0776e
--- /dev/null
+++ b/test/modules/character_stop_code_test_m.F90
@@ -0,0 +1,62 @@
+! Copyright (c) 2024-2025, The Regents of the University of California and Sourcery Institute
+! Terms of use are as specified in LICENSE.txt
+
+#include "language-support.F90"
+
+module character_stop_code_test_m
+  !! Check data partitioning across bins
+  use julienne_m, only : &
+     character_stop_code &
+    ,operator(.all.) &
+    ,operator(.equalsExpected.) &
+    ,passing_test &
+    ,string_t &
+    ,test_description_t &
+    ,test_diagnosis_t &
+    ,test_result_t &
+    ,test_t &
+    ,usher
+  implicit none
+
+  private
+  public :: character_stop_code_test_t
+
+  type, extends(test_t) :: character_stop_code_test_t
+  contains
+    procedure, nopass :: subject
+    procedure, nopass :: results
+  end type
+
+contains
+
+  pure function subject() result(specimen)
+    character(len=:), allocatable :: specimen
+    specimen = "The character_stop_code function"
+  end function
+
+  function results() result(test_results)
+    type(test_result_t), allocatable :: test_results(:)
+    type(test_description_t), allocatable :: test_descriptions(:)
+    type(character_stop_code_test_t) character_stop_code_test
+
+    test_descriptions = [ &
+      test_description_t(string_t("converting a 1D array to a comma-separated-value string"), usher(check_1D_array)) &
+    ]
+    test_results = character_stop_code_test%run(test_descriptions)
+  end function
+
+  function check_1D_array() result(test_diagnosis)
+    !! Check conversion of a 1D array to a character string containing comma-separated values
+    type(test_diagnosis_t) test_diagnosis
+
+    integer, parameter :: expected_array(*) = [1,2,3,4]
+    integer actual_array(size(expected_array))
+
+
+    test_diagnosis = passing_test()
+
+    read(character_stop_code(expected_array),*) actual_array
+    test_diagnosis = .all. (actual_array .equalsExpected. expected_array)
+  end function
+
+end module character_stop_code_test_m

From 57806be06c2da0c2e4210107f1064f7caf6dd053 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Fri, 26 Jun 2026 18:41:36 -0600
Subject: [PATCH 04/18] test(character_stop_code): check comma count

---
 test/modules/character_stop_code_test_m.F90 | 27 +++++++++++++++------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index 8efa0776e..2479518ed 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -7,7 +7,9 @@ module character_stop_code_test_m
   !! Check data partitioning across bins
   use julienne_m, only : &
      character_stop_code &
+    ,operator(//) &
     ,operator(.all.) &
+    ,operator(.also.) &
     ,operator(.equalsExpected.) &
     ,passing_test &
     ,string_t &
@@ -27,6 +29,10 @@ module character_stop_code_test_m
     procedure, nopass :: results
   end type
 
+  interface operator(.occurrencesIn.)
+    module procedure occurrences_in
+  end interface
+
 contains
 
   pure function subject() result(specimen)
@@ -40,23 +46,30 @@ function results() result(test_results)
     type(character_stop_code_test_t) character_stop_code_test
 
     test_descriptions = [ &
-      test_description_t(string_t("converting a 1D array to a comma-separated-value string"), usher(check_1D_array)) &
+      test_description_t(string_t("converting a 1D array to a comma-separated-value (CSV) string"), usher(check_1D_array)) &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
 
+  pure function occurrences_in(lhs, rhs) result(occurrences)
+    character(len=1), intent(in) :: lhs
+    character(len=*), intent(in) :: rhs
+    integer occurrences, c
+    occurrences = count([(rhs(c:c)==lhs, c=1,len(rhs))])
+  end function
+
   function check_1D_array() result(test_diagnosis)
-    !! Check conversion of a 1D array to a character string containing comma-separated values
     type(test_diagnosis_t) test_diagnosis
-
     integer, parameter :: expected_array(*) = [1,2,3,4]
-    integer actual_array(size(expected_array))
-
+    integer c, actual_array(size(expected_array))
 
     test_diagnosis = passing_test()
 
-    read(character_stop_code(expected_array),*) actual_array
-    test_diagnosis = .all. (actual_array .equalsExpected. expected_array)
+    associate(stop_code => character_stop_code(expected_array))
+      read(stop_code,*) actual_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
+      test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_array)-1) // " commas in " // stop_code
+    end associate
   end function
 
 end module character_stop_code_test_m

From cc072461931a40ec8e99fdf721517601c18ec88c Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Fri, 26 Jun 2026 19:24:10 -0600
Subject: [PATCH 05/18] fix(character_stop_code): rm extraneous commas

---
 src/julienne/julienne_stop_and_print_m.F90 | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index bea27f169..c8afa48ea 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -3,7 +3,7 @@
 
 module julienne_stop_and_print_m
   !! Define a pure subroutine subroutine that prints string_t objects/arrays
-  use julienne_string_m, only : string_t, operator(.csv.)
+  use julienne_string_m, only : string_t, operator(.csv.), operator(.separatedBy.)
   implicit none
   
   private
@@ -81,19 +81,19 @@ pure function character_stop_code(stuff) result(stop_code)
       rank(2)
         select type(stuff)
           type is(character(len=*))
-            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
             stop_code = stringy_stuff%string()
           type is(complex)
-            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
             stop_code = stringy_stuff%string()
           type is(double precision)
-            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
             stop_code = stringy_stuff%string()
           type is(integer)
-            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
             stop_code = stringy_stuff%string()
           type is(real)
-            stringy_stuff = .csv. [(.csv. string_t(stuff(row,:)) // new_line(''), row=1,size(stuff,2))]
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
             stop_code = stringy_stuff%string()
           class default
              error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type"

From 480acf7773651da5344421d6fd6c1ccde9b7eaff Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sat, 27 Jun 2026 06:10:12 -0600
Subject: [PATCH 06/18] test(character_stop_code): 2D integer array passes

---
 test/modules/character_stop_code_test_m.F90 | 33 ++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index 2479518ed..eec63c581 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -46,7 +46,8 @@ function results() result(test_results)
     type(character_stop_code_test_t) character_stop_code_test
 
     test_descriptions = [ &
-      test_description_t(string_t("converting a 1D array to a comma-separated-value (CSV) string"), usher(check_1D_array)) &
+       test_description_t(string_t("converting a 1D array to a comma-separated-value (CSV) string"), usher(check_1D_array)) &
+      ,test_description_t(string_t("converting a 2D array to new-line-separated CSV strings"), usher(check_2D_array)) &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
@@ -58,6 +59,16 @@ pure function occurrences_in(lhs, rhs) result(occurrences)
     occurrences = count([(rhs(c:c)==lhs, c=1,len(rhs))])
   end function
 
+  function search_and_replace(string, search_for, replace_with) result(replacement_string)
+    character(len=*), intent(in) :: string
+    character(len=1), intent(in) :: search_for, replace_with
+    character(len=len(string)) :: replacement_string
+
+    do concurrent(integer :: c = 1:len(string))
+      replacement_string(c:c) = merge(string(c:c), replace_with, string(c:c)/=search_for)
+    end do
+  end function
+
   function check_1D_array() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
     integer, parameter :: expected_array(*) = [1,2,3,4]
@@ -72,4 +83,24 @@ function check_1D_array() result(test_diagnosis)
     end associate
   end function
 
+  function check_2D_array() result(test_diagnosis)
+    type(test_diagnosis_t) test_diagnosis
+    integer, parameter :: expected_array(*,*) = reshape([1,2,3,4,5,6], [2,3])
+    integer actual_array(size(expected_array,1),size(expected_array,2))
+
+    test_diagnosis = passing_test()
+
+    associate( &
+       stop_code => character_stop_code(expected_array) &
+      ,rows => size(expected_array,1) &
+      ,cols => size(expected_array,2) &
+    )
+      read(stop_code,*) actual_array(1,:), actual_array(2,:)
+
+      test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
+      test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
+      test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
+    end associate
+  end function
+
 end module character_stop_code_test_m

From 9b32f8c8a45dc024517cbf02d77374ce7b1a03a5 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sat, 27 Jun 2026 17:30:51 -0600
Subject: [PATCH 07/18] test(character_stop_code): 2D/3D real/integer arrays

---
 src/julienne/julienne_stop_and_print_m.F90  |  26 ++++-
 test/modules/character_stop_code_test_m.F90 | 117 ++++++++++++++++++--
 2 files changed, 127 insertions(+), 16 deletions(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index c8afa48ea..dc18b6675 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -17,7 +17,6 @@ module julienne_stop_and_print_m
 
 contains 
 
-
   pure subroutine print_string(message)
     implicit none
     type(string_t), intent(in) :: message
@@ -36,7 +35,7 @@ pure function character_stop_code(stuff) result(stop_code)
     character(len=:), allocatable :: stop_code
 
     type(string_t) stringy_stuff
-    integer row
+    integer row, page
 
     select rank(stuff)
       rank(0)
@@ -56,7 +55,7 @@ pure function character_stop_code(stuff) result(stop_code)
             stringy_stuff = string_t(stuff)
             stop_code = stringy_stuff%string()
           class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported type"
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for scalar"
         end select
       rank(1)
         select type(stuff)
@@ -76,7 +75,7 @@ pure function character_stop_code(stuff) result(stop_code)
             stringy_stuff = .csv. string_t(stuff)
             stop_code = stringy_stuff%string()
           class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type"
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-1 array"
         end select
       rank(2)
         select type(stuff)
@@ -96,7 +95,24 @@ pure function character_stop_code(stuff) result(stop_code)
             stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
             stop_code = stringy_stuff%string()
           class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type"
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-2 array"
+        end select
+      rank(3)
+        select type(stuff)
+          type is(complex)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          type is(real)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          class default
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-3 array"
         end select
       rank default
         associate(stop_code_rank => string_t(stop_code))
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index eec63c581..544f34a2f 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -10,7 +10,9 @@ module character_stop_code_test_m
     ,operator(//) &
     ,operator(.all.) &
     ,operator(.also.) &
+    ,operator(.approximates.) &
     ,operator(.equalsExpected.) &
+    ,operator(.within.) &
     ,passing_test &
     ,string_t &
     ,test_description_t &
@@ -46,8 +48,9 @@ function results() result(test_results)
     type(character_stop_code_test_t) character_stop_code_test
 
     test_descriptions = [ &
-       test_description_t(string_t("converting a 1D array to a comma-separated-value (CSV) string"), usher(check_1D_array)) &
-      ,test_description_t(string_t("converting a 2D array to new-line-separated CSV strings"), usher(check_2D_array)) &
+       test_description_t(string_t("converting a 1D arrays to a comma-separated-value (CSV) strings"), usher(check_1D_array)) &
+      ,test_description_t(string_t("converting a 2D arrays to new-line-separated CSV strings"), usher(check_2D_array)) &
+      ,test_description_t(string_t("converting a 3D arrays to new-line-separated CSV strings"), usher(check_3D_array)) &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
@@ -59,35 +62,74 @@ pure function occurrences_in(lhs, rhs) result(occurrences)
     occurrences = count([(rhs(c:c)==lhs, c=1,len(rhs))])
   end function
 
-  function search_and_replace(string, search_for, replace_with) result(replacement_string)
+  function search_and_replace(string, search_for, replace_with, except_final) result(replacement_string)
     character(len=*), intent(in) :: string
     character(len=1), intent(in) :: search_for, replace_with
-    character(len=len(string)) :: replacement_string
-
-    do concurrent(integer :: c = 1:len(string))
-      replacement_string(c:c) = merge(string(c:c), replace_with, string(c:c)/=search_for)
+    character(len=:), allocatable :: replacement_string
+    logical, intent(in), optional :: except_final
+    integer c, c_final, c_
+
+    allocate(character(len=len(string)) :: replacement_string)
+
+    c_final = 0
+    c_ = 0
+    do c = 1, len(string)
+      c_ = c_ + 1
+      if (string(c:c)==search_for) then
+        c_final = c
+        if (c>1) then
+          if (string(c-1:c-1) /= search_for) then
+            replacement_string(c_:c_) = replace_with
+          else
+            c_ = c_ - 1
+          end if
+        end if
+      else
+        replacement_string(c_:c_) = string(c:c)
+      end if
     end do
+    if (present(except_final)) then
+      if (except_final .and. c_final>0) replacement_string(c_final:c_final) = search_for
+    end if
+
+    replacement_string = trim(replacement_string)
   end function
 
   function check_1D_array() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
+
     integer, parameter :: expected_array(*) = [1,2,3,4]
-    integer c, actual_array(size(expected_array))
+    integer actual_array(size(expected_array))
+
+    real, parameter :: expected_real_array(*) = real(expected_array)
+    real actual_real_array(size(expected_real_array,1))
 
     test_diagnosis = passing_test()
 
     associate(stop_code => character_stop_code(expected_array))
       read(stop_code,*) actual_array
       test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
-      test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_array)-1) // " commas in " // stop_code
+      test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_array)-1)  &
+        // " commas in " // stop_code
+    end associate
+
+    associate(stop_code => character_stop_code(expected_real_array))
+      read(stop_code,*) actual_real_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. real(expected_array) .within. 0.)
+      test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_real_array)-1) &
+        // " commas in " // stop_code
     end associate
   end function
 
   function check_2D_array() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
-    integer, parameter :: expected_array(*,*) = reshape([1,2,3,4,5,6], [2,3])
+
+    integer, parameter :: expected_array(*,*) = reshape([11,21,12,22,13,23], [2,3])
     integer actual_array(size(expected_array,1),size(expected_array,2))
 
+    real, parameter :: expected_real_array(*,*) = real(expected_array)
+    real  actual_real_array(size(expected_array,1),size(expected_array,2))
+
     test_diagnosis = passing_test()
 
     associate( &
@@ -96,11 +138,64 @@ function check_2D_array() result(test_diagnosis)
       ,cols => size(expected_array,2) &
     )
       read(stop_code,*) actual_array(1,:), actual_array(2,:)
-
       test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
       test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
       test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
     end associate
+
+    associate( &
+       stop_code => character_stop_code(expected_real_array) &
+      ,rows => size(expected_real_array,1) &
+      ,cols => size(expected_real_array,2) &
+    )
+      associate(one_line => search_and_replace(stop_code, search_for=new_line(''), replace_with=","))
+        read(one_line,*) actual_real_array(1,:), actual_real_array(2,:)
+        test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. real(expected_array) .within. 0.)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
+      end associate
+    end associate
+  end function
+
+  function check_3D_array() result(test_diagnosis)
+    type(test_diagnosis_t) test_diagnosis
+    integer, parameter :: expected_array(*,*,*) = reshape([111,211,121,221, 112,212,122,222, 113,213,123,223], [2,2,3])
+    integer actual_array(size(expected_array,1),size(expected_array,2),size(expected_array,3))
+
+    real, parameter :: expected_real_array(*,*,*) = real(expected_array)
+    real  actual_real_array(size(expected_real_array,1),size(expected_real_array,2),size(expected_real_array,3))
+
+    test_diagnosis = passing_test()
+
+    associate( &
+       stop_code => character_stop_code(expected_array) &
+      ,rows  => size(expected_array,1) &
+      ,cols  => size(expected_array,2) &
+      ,pages => size(expected_array,3) &
+    )
+      associate(one_line => search_and_replace(stop_code, search_for=new_line(''), replace_with=","))
+        read(one_line,'(*(i3,1x))') actual_array(1,:,1), actual_array(2,:,1), actual_array(1,:,2), actual_array(2,:,2), actual_array(1,:,3), actual_array(2,:,3)
+        test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows*pages) // " commas"
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. (rows*pages-1) + (pages-1)) &
+          // " new-line characters"
+      end associate
+    end associate
+
+    associate( &
+       stop_code => character_stop_code(expected_real_array) &
+      ,rows  => size(expected_real_array,1) &
+      ,cols  => size(expected_real_array,2) &
+      ,pages => size(expected_real_array,3) &
+    )
+      associate(one_line => trim(search_and_replace(stop_code, search_for=new_line(''), replace_with=",")))
+        read(one_line(1:179),*) actual_real_array(1,:,1), actual_real_array(2,:,1), actual_real_array(1,:,2), actual_real_array(2,:,2), actual_real_array(1,:,3), actual_real_array(2,:,3)
+        test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. expected_real_array .within. 0.)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows*pages) // " commas"
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. (rows*pages-1) + (pages-1)) &
+          // " new-line characters"
+      end associate
+    end associate
   end function
 
 end module character_stop_code_test_m

From ff9102dd36854cbc1b7d7979990f98f3b4b7f948 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sat, 27 Jun 2026 18:51:56 -0600
Subject: [PATCH 08/18] test(character_stop_code): 1D complex array

---
 test/modules/character_stop_code_test_m.F90 | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index 544f34a2f..fa17d0802 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -104,6 +104,10 @@ function check_1D_array() result(test_diagnosis)
     real, parameter :: expected_real_array(*) = real(expected_array)
     real actual_real_array(size(expected_real_array,1))
 
+    complex, parameter :: i = (0.,1.)
+    complex, parameter :: expected_complex_array(*) = cmplx(expected_array) - expected_array*i
+    complex actual_complex_array(size(expected_complex_array,1))
+
     test_diagnosis = passing_test()
 
     associate(stop_code => character_stop_code(expected_array))
@@ -119,6 +123,12 @@ function check_1D_array() result(test_diagnosis)
       test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_real_array)-1) &
         // " commas in " // stop_code
     end associate
+
+    associate(stop_code => character_stop_code(expected_complex_array), expected_imaginary_part => -expected_array*i)
+      read(stop_code,*) actual_complex_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%re .approximates. real(expected_array) .within. 0.)
+      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%im .approximates. expected_imaginary_part %im .within. 0.)
+    end associate
   end function
 
   function check_2D_array() result(test_diagnosis)

From 06834911ff9b96833325b9de39e93680316ab765 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sat, 27 Jun 2026 19:10:44 -0600
Subject: [PATCH 09/18] test(character_stop_code): {1,2,3}D dble prec arrays

---
 test/modules/character_stop_code_test_m.F90 | 44 +++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index fa17d0802..f2ff12f57 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -108,6 +108,9 @@ function check_1D_array() result(test_diagnosis)
     complex, parameter :: expected_complex_array(*) = cmplx(expected_array) - expected_array*i
     complex actual_complex_array(size(expected_complex_array,1))
 
+    double precision, parameter :: expected_dble_array(*) = dble(expected_array)
+    double precision actual_dble_array(size(expected_dble_array,1))
+
     test_diagnosis = passing_test()
 
     associate(stop_code => character_stop_code(expected_array))
@@ -129,6 +132,13 @@ function check_1D_array() result(test_diagnosis)
       test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%re .approximates. real(expected_array) .within. 0.)
       test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%im .approximates. expected_imaginary_part %im .within. 0.)
     end associate
+
+    associate(stop_code => character_stop_code(expected_dble_array))
+      read(stop_code,*) actual_dble_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. dble(expected_array) .within. 0D0)
+      test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_dble_array)-1) &
+        // " commas in " // stop_code
+    end associate
   end function
 
   function check_2D_array() result(test_diagnosis)
@@ -140,6 +150,9 @@ function check_2D_array() result(test_diagnosis)
     real, parameter :: expected_real_array(*,*) = real(expected_array)
     real  actual_real_array(size(expected_array,1),size(expected_array,2))
 
+    double precision, parameter :: expected_dble_array(*,*) = dble(expected_array)
+    double precision actual_dble_array(size(expected_dble_array,1), size(expected_dble_array,2))
+
     test_diagnosis = passing_test()
 
     associate( &
@@ -165,6 +178,19 @@ function check_2D_array() result(test_diagnosis)
         test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
       end associate
     end associate
+
+    associate( &
+       stop_code => character_stop_code(expected_dble_array) &
+      ,rows => size(expected_dble_array,1) &
+      ,cols => size(expected_dble_array,2) &
+    )
+      associate(one_line => search_and_replace(stop_code, search_for=new_line(''), replace_with=","))
+        read(one_line,*) actual_dble_array(1,:), actual_dble_array(2,:)
+        test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. dble(expected_array) .within. 0D0)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
+      end associate
+    end associate
   end function
 
   function check_3D_array() result(test_diagnosis)
@@ -175,6 +201,9 @@ function check_3D_array() result(test_diagnosis)
     real, parameter :: expected_real_array(*,*,*) = real(expected_array)
     real  actual_real_array(size(expected_real_array,1),size(expected_real_array,2),size(expected_real_array,3))
 
+    double precision, parameter :: expected_dble_array(*,*,*) = dble(expected_array)
+    double precision actual_dble_array(size(expected_dble_array,1), size(expected_dble_array,2), size(expected_dble_array,3))
+
     test_diagnosis = passing_test()
 
     associate( &
@@ -206,6 +235,21 @@ function check_3D_array() result(test_diagnosis)
           // " new-line characters"
       end associate
     end associate
+
+    associate( &
+       stop_code => character_stop_code(expected_dble_array) &
+      ,rows  => size(expected_dble_array,1) &
+      ,cols  => size(expected_dble_array,2) &
+      ,pages => size(expected_dble_array,3) &
+    )
+      associate(one_line => trim(search_and_replace(stop_code, search_for=new_line(''), replace_with=",")))
+        read(one_line(1:179),*) actual_dble_array(1,:,1), actual_dble_array(2,:,1), actual_dble_array(1,:,2), actual_dble_array(2,:,2), actual_dble_array(1,:,3), actual_dble_array(2,:,3)
+        test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. expected_dble_array .within. 0D0)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows*pages) // " commas"
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. (rows*pages-1) + (pages-1)) &
+          // " new-line characters"
+      end associate
+    end associate
   end function
 
 end module character_stop_code_test_m

From aed7e2bbf23d242940a027f61fa8459d0ad80697 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 19:38:58 -0700
Subject: [PATCH 10/18] build/test(print_and_stop): gfortran workarounds

This commit works around several build-time and runtime gfortran
conpiler bugs.
---
 src/julienne/julienne_stop_and_print_m.F90  |   8 +
 test/modules/character_stop_code_test_m.F90 | 228 +++++++++++++++++++-
 2 files changed, 230 insertions(+), 6 deletions(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index dc18b6675..7105ce8f5 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -27,7 +27,15 @@ pure subroutine print_header_and_data(header, data)
     implicit none
     character(len=*), intent(in) :: header
     class(*), intent(in) :: data
+#ifndef __GFORTRAN__
     error stop new_line('') // header // new_line('') // character_stop_code(data)
+#else
+    block
+      character(len=:), allocatable :: code
+      code = new_line('') // header // new_line('') // character_stop_code(data)
+      error stop code
+    end block
+#endif
   end subroutine
 
   pure function character_stop_code(stuff) result(stop_code)
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index f2ff12f57..763db1df4 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -48,9 +48,10 @@ function results() result(test_results)
     type(character_stop_code_test_t) character_stop_code_test
 
     test_descriptions = [ &
-       test_description_t(string_t("converting a 1D arrays to a comma-separated-value (CSV) strings"), usher(check_1D_array)) &
-      ,test_description_t(string_t("converting a 2D arrays to new-line-separated CSV strings"), usher(check_2D_array)) &
-      ,test_description_t(string_t("converting a 3D arrays to new-line-separated CSV strings"), usher(check_3D_array)) &
+       test_description_t(string_t("converting scalars to character stop codes"), usher(check_scalars)) &
+      ,test_description_t(string_t("converting 1D arrays to comma-separated-value (CSV) character stop codes"), usher(check_1D_array)) &
+      ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes"), usher(check_2D_array)) &
+      ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes"), usher(check_3D_array)) &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
@@ -95,6 +96,69 @@ function search_and_replace(string, search_for, replace_with, except_final) resu
     replacement_string = trim(replacement_string)
   end function
 
+  function check_scalars() result(test_diagnosis)
+    type(test_diagnosis_t) test_diagnosis
+
+    integer, parameter :: expected_integer_value  = 42
+    integer actual_value
+
+    real, parameter :: expected_real_value = real(expected_integer_value)
+    real actual_real_value
+    
+    complex, parameter :: i = (0.,1.), expected_complex_value = cmplx(expected_integer_value) - expected_integer_value*i
+    complex actual_complex_value
+
+    double precision, parameter :: expected_dble_value = dble(expected_integer_value)
+    double precision actual_dble_value
+
+    test_diagnosis = passing_test()
+
+#ifndef __GFORTRAN__
+    associate(stop_code => character_stop_code(expected_integer_value))
+      read(stop_code,*) actual_value
+    end associate
+    test_diagnosis = test_diagnosis .also. (actual_value .equalsExpected. expected_integer_value) // " for an integer value"
+
+    associate(stop_code => character_stop_code(expected_real_value))
+      read(stop_code,*) actual_real_value
+    end associate
+    test_diagnosis = test_diagnosis .also. (actual_real_value .approximates. expected_real_value .within. 0.) // " for a real value"
+
+    associate(stop_code => character_stop_code(expected_complex_value))
+      read(stop_code,*) actual_complex_value
+    end associate
+    test_diagnosis = test_diagnosis .also. (actual_complex_value%Re .approximates. expected_complex_value%Re .within. 0.) // " for the real part of a complex value"
+    test_diagnosis = test_diagnosis .also. (actual_complex_value%Im .approximates. expected_complex_value%Im .within. 0.) // " for the imaginary part of a complex value"
+
+    associate(stop_code => character_stop_code(expected_dble_value))
+      read(stop_code,*) actual_dble_value
+    end associate
+    test_diagnosis = test_diagnosis .also. (actual_dble_value .approximates. expected_dble_value .within. 0D0) // " for a double-precision value"
+#else
+    block
+      character(len=:), allocatable  :: stop_code
+
+      stop_code = character_stop_code(expected_integer_value)
+      read(stop_code,*) actual_value
+      test_diagnosis = test_diagnosis .also. (actual_value .equalsExpected. expected_integer_value)
+
+      stop_code = character_stop_code(expected_real_value)
+      read(stop_code,*) actual_real_value
+      test_diagnosis = test_diagnosis .also. (actual_real_value .approximates. expected_real_value .within. 0.)
+
+      stop_code = character_stop_code(expected_complex_value)
+      read(stop_code,*) actual_complex_value
+      test_diagnosis = test_diagnosis .also. (actual_complex_value%Re .approximates. expected_complex_value%Re .within. 0.)
+      test_diagnosis = test_diagnosis .also. (actual_complex_value%Im .approximates. expected_complex_value%Im .within. 0.)
+
+      stop_code = character_stop_code(expected_dble_value)
+      read(stop_code,*) actual_dble_value
+      test_diagnosis = test_diagnosis .also. (actual_dble_value .approximates. expected_dble_value .within. 0D0)
+    end block
+#endif
+
+  end function
+
   function check_1D_array() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
 
@@ -111,34 +175,79 @@ function check_1D_array() result(test_diagnosis)
     double precision, parameter :: expected_dble_array(*) = dble(expected_array)
     double precision actual_dble_array(size(expected_dble_array,1))
 
+    integer c
+
     test_diagnosis = passing_test()
 
+#ifndef __GFORTRAN__
     associate(stop_code => character_stop_code(expected_array))
       read(stop_code,*) actual_array
       test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
       test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_array)-1)  &
         // " commas in " // stop_code
     end associate
+#else
+    block 
+      character(len=:), allocatable :: stop_code
+      stop_code = character_stop_code(expected_array)
+      read(stop_code,*) actual_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
+      test_diagnosis = test_diagnosis .also.  (count([(stop_code(c:c)==",", c=1,len(stop_code))])  .equalsExpected. size(expected_array)-1) &
+        // " commas in " // stop_code
+    end block
+#endif
 
+#ifndef __GFORTRAN__
     associate(stop_code => character_stop_code(expected_real_array))
       read(stop_code,*) actual_real_array
       test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. real(expected_array) .within. 0.)
       test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_real_array)-1) &
         // " commas in " // stop_code
     end associate
+#else
+    block 
+      character(len=:), allocatable :: stop_code
+      stop_code = character_stop_code(expected_real_array)
+      read(stop_code,*) actual_real_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. real(expected_array) .within. 0.)
+      test_diagnosis = test_diagnosis .also.  (count([(stop_code(c:c)==",", c=1,len(stop_code))])  .equalsExpected. size(expected_real_array)-1) &
+          // " commas in " // stop_code
+    end block
+#endif
 
+#ifndef __GFORTRAN__
     associate(stop_code => character_stop_code(expected_complex_array), expected_imaginary_part => -expected_array*i)
       read(stop_code,*) actual_complex_array
-      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%re .approximates. real(expected_array) .within. 0.)
-      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%im .approximates. expected_imaginary_part %im .within. 0.)
+      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%Re .approximates. real(expected_array) .within. 0.)
+      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%Im .approximates. expected_imaginary_part%Im .within. 0.)
     end associate
+#else
+    block 
+      character(len=:), allocatable :: stop_code
+      stop_code = character_stop_code(expected_complex_array)
+      read(stop_code,*) actual_complex_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%Re .approximates. expected_complex_array%Re .within. 0.)
+      test_diagnosis = test_diagnosis .also. .all. (actual_complex_array%Im .approximates. expected_complex_array%Im .within. 0.)
+    end block
+#endif
 
+#ifndef __GFORTRAN__
     associate(stop_code => character_stop_code(expected_dble_array))
       read(stop_code,*) actual_dble_array
       test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. dble(expected_array) .within. 0D0)
       test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. size(expected_dble_array)-1) &
         // " commas in " // stop_code
     end associate
+#else
+    block 
+      character(len=:), allocatable :: stop_code
+      stop_code = character_stop_code(expected_dble_array)
+      read(stop_code,*) actual_dble_array
+      test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. expected_dble_array .within. 0D0)
+      test_diagnosis = test_diagnosis .also.  (count([(stop_code(c:c)==",", c=1,len(stop_code))])  .equalsExpected. size(expected_dble_array)-1) &
+        // " commas in " // stop_code
+    end block 
+#endif
   end function
 
   function check_2D_array() result(test_diagnosis)
@@ -155,6 +264,7 @@ function check_2D_array() result(test_diagnosis)
 
     test_diagnosis = passing_test()
 
+#ifndef __GFORTRAN__
     associate( &
        stop_code => character_stop_code(expected_array) &
       ,rows => size(expected_array,1) &
@@ -165,7 +275,23 @@ function check_2D_array() result(test_diagnosis)
       test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
       test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
     end associate
+#else
+    block
+      character(len=:), allocatable :: stop_code
+      stop_code = character_stop_code(expected_array)
+      associate( &
+         rows => size(expected_array,1) &
+        ,cols => size(expected_array,2) &
+      )
+        read(stop_code,*) actual_array(1,:), actual_array(2,:)
+        test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
+      end associate
+    end block
+#endif
 
+#ifndef __GFORTRAN__
     associate( &
        stop_code => character_stop_code(expected_real_array) &
       ,rows => size(expected_real_array,1) &
@@ -178,7 +304,24 @@ function check_2D_array() result(test_diagnosis)
         test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
       end associate
     end associate
+#else
+    block
+      character(len=:), allocatable :: stop_code, one_line
+      stop_code = character_stop_code(expected_real_array)
+      associate( &
+         rows => size(expected_real_array,1) &
+        ,cols => size(expected_real_array,2) &
+      )
+        one_line = search_and_replace(stop_code, search_for=new_line(''), replace_with=",")
+        read(one_line,*) actual_real_array(1,:), actual_real_array(2,:)
+        test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. real(expected_array) .within. 0.)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
+      end associate
+    end block
+#endif
 
+#ifndef __GFORTRAN__
     associate( &
        stop_code => character_stop_code(expected_dble_array) &
       ,rows => size(expected_dble_array,1) &
@@ -191,6 +334,22 @@ function check_2D_array() result(test_diagnosis)
         test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
       end associate
     end associate
+#else
+    block
+      character(len=:), allocatable :: stop_code, one_line
+      stop_code = character_stop_code(expected_dble_array)
+      associate( &
+         rows => size(expected_dble_array,1) &
+        ,cols => size(expected_dble_array,2) &
+      )
+        one_line = search_and_replace(stop_code, search_for=new_line(''), replace_with=",")
+        read(one_line,*) actual_dble_array(1,:), actual_dble_array(2,:)
+        test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. dble(expected_array) .within. 0D0)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows)
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. rows-1)
+      end associate
+    end block
+#endif
   end function
 
   function check_3D_array() result(test_diagnosis)
@@ -206,6 +365,7 @@ function check_3D_array() result(test_diagnosis)
 
     test_diagnosis = passing_test()
 
+#ifndef __GFORTRAN__
     associate( &
        stop_code => character_stop_code(expected_array) &
       ,rows  => size(expected_array,1) &
@@ -220,7 +380,26 @@ function check_3D_array() result(test_diagnosis)
           // " new-line characters"
       end associate
     end associate
+#else
+    block
+      character(len=:), allocatable :: stop_code, one_line
+      stop_code = character_stop_code(expected_array)
+      associate( &
+         rows  => size(expected_array,1) &
+        ,cols  => size(expected_array,2) &
+        ,pages => size(expected_array,3) &
+      )
+        one_line = search_and_replace(stop_code, search_for=new_line(''), replace_with=",")
+        read(one_line,'(*(i3,1x))') actual_array(1,:,1), actual_array(2,:,1), actual_array(1,:,2), actual_array(2,:,2), actual_array(1,:,3), actual_array(2,:,3)
+        test_diagnosis = test_diagnosis .also. .all. (actual_array .equalsExpected. expected_array)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows*pages) // " commas"
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. (rows*pages-1) + (pages-1)) &
+          // " new-line characters"
+      end associate
+    end block
+#endif
 
+#ifndef __GFORTRAN__
     associate( &
        stop_code => character_stop_code(expected_real_array) &
       ,rows  => size(expected_real_array,1) &
@@ -235,7 +414,26 @@ function check_3D_array() result(test_diagnosis)
           // " new-line characters"
       end associate
     end associate
-
+#else
+      block
+        character(len=:), allocatable :: stop_code, one_line
+        stop_code = character_stop_code(expected_real_array)
+        associate( &
+           rows  => size(expected_real_array,1) &
+          ,cols  => size(expected_real_array,2) &
+          ,pages => size(expected_real_array,3) &
+        )
+          one_line = trim(search_and_replace(stop_code, search_for=new_line(''), replace_with=","))
+          read(one_line(1:179),*) actual_real_array(1,:,1), actual_real_array(2,:,1), actual_real_array(1,:,2), actual_real_array(2,:,2), actual_real_array(1,:,3), actual_real_array(2,:,3)
+          test_diagnosis = test_diagnosis .also. .all. (actual_real_array .approximates. expected_real_array .within. 0.)
+          test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows*pages) // " commas"
+          test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. (rows*pages-1) + (pages-1)) &
+            // " new-line characters"
+        end associate
+      end block
+#endif
+
+#ifndef __GFORTRAN__
     associate( &
        stop_code => character_stop_code(expected_dble_array) &
       ,rows  => size(expected_dble_array,1) &
@@ -250,6 +448,24 @@ function check_3D_array() result(test_diagnosis)
           // " new-line characters"
       end associate
     end associate
+#else
+    block
+      character(len=:), allocatable :: stop_code, one_line
+      stop_code = character_stop_code(expected_dble_array)
+      associate( &
+         rows  => size(expected_dble_array,1) &
+        ,cols  => size(expected_dble_array,2) &
+        ,pages => size(expected_dble_array,3) &
+      )
+        one_line = trim(search_and_replace(stop_code, search_for=new_line(''), replace_with=","))
+        read(one_line(1:179),*) actual_dble_array(1,:,1), actual_dble_array(2,:,1), actual_dble_array(1,:,2), actual_dble_array(2,:,2), actual_dble_array(1,:,3), actual_dble_array(2,:,3)
+        test_diagnosis = test_diagnosis .also. .all. (actual_dble_array .approximates. expected_dble_array .within. 0D0)
+        test_diagnosis = test_diagnosis .also. (("," .occurrencesIn. stop_code) .equalsExpected. (cols-1)*rows*pages) // " commas"
+        test_diagnosis = test_diagnosis .also. ((new_line('') .occurrencesIn. stop_code) .equalsExpected. (rows*pages-1) + (pages-1)) &
+          // " new-line characters"
+      end associate
+    end block
+#endif
   end function
 
 end module character_stop_code_test_m

From 4f1a41f157d576fb57fd3e5ac6cfa6a53590440c Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 20:36:35 -0700
Subject: [PATCH 11/18] feat(stop_and_print): support 1D string_t arrays

---
 src/julienne/julienne_stop_and_print_m.F90  |  5 ++++
 test/modules/character_stop_code_test_m.F90 | 33 ++++++++++++++++-----
 2 files changed, 30 insertions(+), 8 deletions(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index 7105ce8f5..ff7a5e6b0 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -62,6 +62,8 @@ pure function character_stop_code(stuff) result(stop_code)
           type is(real)
             stringy_stuff = string_t(stuff)
             stop_code = stringy_stuff%string()
+          class is(string_t)
+            stop_code = stuff%string()
           class default
              error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for scalar"
         end select
@@ -82,6 +84,9 @@ pure function character_stop_code(stuff) result(stop_code)
           type is(real)
             stringy_stuff = .csv. string_t(stuff)
             stop_code = stringy_stuff%string()
+          class is(string_t)
+            stringy_stuff = .csv. stuff
+            stop_code = stringy_stuff%string()
           class default
              error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-1 array"
         end select
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index 763db1df4..3475f243d 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -11,6 +11,7 @@ module character_stop_code_test_m
     ,operator(.all.) &
     ,operator(.also.) &
     ,operator(.approximates.) &
+    ,operator(.csv.) &
     ,operator(.equalsExpected.) &
     ,operator(.within.) &
     ,passing_test &
@@ -48,10 +49,11 @@ function results() result(test_results)
     type(character_stop_code_test_t) character_stop_code_test
 
     test_descriptions = [ &
-       test_description_t(string_t("converting scalars to character stop codes"), usher(check_scalars)) &
-      ,test_description_t(string_t("converting 1D arrays to comma-separated-value (CSV) character stop codes"), usher(check_1D_array)) &
-      ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes"), usher(check_2D_array)) &
-      ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes"), usher(check_3D_array)) &
+       test_description_t(string_t("converting scalars to character stop codes")                                  , usher(check_intrinsic_scalars))   &
+      ,test_description_t(string_t("converting 1D arrays to comma-separated-value (CSV) character stop codes")    , usher(check_intrinsic_1D_arrays)) &
+      ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes")         , usher(check_intrinsic_2D_arrays)) &
+      ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes")         , usher(check_intrinsic_3D_arrays)) &
+      ,test_description_t(string_t("converting a 1D string_t array into a CSV character stop code")               , usher(check_string_t_1D_array))      &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
@@ -96,7 +98,7 @@ function search_and_replace(string, search_for, replace_with, except_final) resu
     replacement_string = trim(replacement_string)
   end function
 
-  function check_scalars() result(test_diagnosis)
+  function check_intrinsic_scalars() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
 
     integer, parameter :: expected_integer_value  = 42
@@ -159,7 +161,7 @@ function check_scalars() result(test_diagnosis)
 
   end function
 
-  function check_1D_array() result(test_diagnosis)
+  function check_intrinsic_1D_arrays() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
 
     integer, parameter :: expected_array(*) = [1,2,3,4]
@@ -250,7 +252,7 @@ function check_1D_array() result(test_diagnosis)
 #endif
   end function
 
-  function check_2D_array() result(test_diagnosis)
+  function check_intrinsic_2D_arrays() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
 
     integer, parameter :: expected_array(*,*) = reshape([11,21,12,22,13,23], [2,3])
@@ -352,7 +354,7 @@ function check_2D_array() result(test_diagnosis)
 #endif
   end function
 
-  function check_3D_array() result(test_diagnosis)
+  function check_intrinsic_3D_arrays() result(test_diagnosis)
     type(test_diagnosis_t) test_diagnosis
     integer, parameter :: expected_array(*,*,*) = reshape([111,211,121,221, 112,212,122,222, 113,213,123,223], [2,2,3])
     integer actual_array(size(expected_array,1),size(expected_array,2),size(expected_array,3))
@@ -468,4 +470,19 @@ function check_3D_array() result(test_diagnosis)
 #endif
   end function
 
+  function check_string_t_1D_array() result(test_diagnosis)
+    type(test_diagnosis_t) test_diagnosis
+
+    test_diagnosis = passing_test()
+
+    associate(messages => string_t(["foo","bar"]))
+      associate( &
+         expected_stop_code => .csv. messages &
+        ,stop_code => character_stop_code(messages) &
+      )
+        test_diagnosis = stop_code .equalsExpected. expected_stop_code
+      end associate
+    end associate
+  end function
+
 end module character_stop_code_test_m

From dd3c8151b1d5ec2a89b7cf7a7aabed539fbf9922 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 21:12:39 -0700
Subject: [PATCH 12/18] feat(file_t): add from_character_lines constructor

---
 src/julienne/julienne_file_m.f90 | 8 +++++++-
 src/julienne/julienne_file_s.F90 | 6 +++++-
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/julienne/julienne_file_m.f90 b/src/julienne/julienne_file_m.f90
index 7a113638b..3d4f2fb4b 100644
--- a/src/julienne/julienne_file_m.f90
+++ b/src/julienne/julienne_file_m.f90
@@ -31,12 +31,18 @@ module function from_file_with_character_name(file_name) result(file_object)
       type(file_t) file_object
     end function
 
-    pure module function from_lines(lines) result(file_object)
+    pure module function from_string_t_lines(lines) result(file_object)
       implicit none
       type(string_t), intent(in) :: lines(:)
       type(file_t) file_object
     end function
 
+    pure module function from_character_lines(lines) result(file_object)
+      implicit none
+      character(len=*), intent(in) :: lines(:)
+      type(file_t) file_object
+    end function
+
   end interface
 
   interface
diff --git a/src/julienne/julienne_file_s.F90 b/src/julienne/julienne_file_s.F90
index bfa6dd19a..e243640eb 100644
--- a/src/julienne/julienne_file_s.F90
+++ b/src/julienne/julienne_file_s.F90
@@ -42,10 +42,14 @@
     call self%write_to_character_file_name(file_name%string())
   end procedure
 
-  module procedure from_lines
+  module procedure from_string_t_lines
     allocate(file_object%lines_, source=lines)
   end procedure
 
+  module procedure from_character_lines
+    allocate(file_object%lines_, source=string_t(lines))
+  end procedure
+
   module procedure from_file_with_character_name
     file_object = from_file_with_string_name(string_t(file_name))
   end procedure

From 404da0307cf2335e80b20a07236a1ceb7644cca6 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 21:14:21 -0700
Subject: [PATCH 13/18] feat(character_stop_code): support file_t

---
 src/julienne/julienne_stop_and_print_m.F90  |  4 ++++
 test/modules/character_stop_code_test_m.F90 | 21 ++++++++++++++++++++-
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index ff7a5e6b0..9f354a8c4 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -4,6 +4,7 @@
 module julienne_stop_and_print_m
   !! Define a pure subroutine subroutine that prints string_t objects/arrays
   use julienne_string_m, only : string_t, operator(.csv.), operator(.separatedBy.)
+  use julienne_file_m, only : file_t
   implicit none
   
   private
@@ -56,6 +57,9 @@ pure function character_stop_code(stuff) result(stop_code)
           type is(double precision)
             stringy_stuff = string_t(stuff)
             stop_code = stringy_stuff%string()
+          type is(file_t)
+            stringy_stuff = stuff%lines() .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
           type is(integer)
             stringy_stuff = string_t(stuff)
             stop_code = stringy_stuff%string()
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index 3475f243d..c1fcef974 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -6,13 +6,14 @@
 module character_stop_code_test_m
   !! Check data partitioning across bins
   use julienne_m, only : &
-     character_stop_code &
+     file_t &
     ,operator(//) &
     ,operator(.all.) &
     ,operator(.also.) &
     ,operator(.approximates.) &
     ,operator(.csv.) &
     ,operator(.equalsExpected.) &
+    ,operator(.separatedBy.) &
     ,operator(.within.) &
     ,passing_test &
     ,string_t &
@@ -21,6 +22,8 @@ module character_stop_code_test_m
     ,test_result_t &
     ,test_t &
     ,usher
+  use julienne_stop_and_print_m, only : character_stop_code
+
   implicit none
 
   private
@@ -54,6 +57,7 @@ function results() result(test_results)
       ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes")         , usher(check_intrinsic_2D_arrays)) &
       ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes")         , usher(check_intrinsic_3D_arrays)) &
       ,test_description_t(string_t("converting a 1D string_t array into a CSV character stop code")               , usher(check_string_t_1D_array))      &
+      ,test_description_t(string_t("converting a file_t object into a new-line-separated character stop code")    , usher(check_file_t))      &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
@@ -485,4 +489,19 @@ function check_string_t_1D_array() result(test_diagnosis)
     end associate
   end function
 
+  function check_file_t() result(test_diagnosis)
+    type(test_diagnosis_t) test_diagnosis
+
+    test_diagnosis = passing_test()
+
+    associate(file_ => file_t(["yada","yada"]))
+      associate( &
+         expected_stop_code => file_%lines() .separatedBy. new_line('') &
+        ,stop_code => character_stop_code(file_) &
+      )
+        test_diagnosis = stop_code .equalsExpected. expected_stop_code
+      end associate
+    end associate
+  end function
+
 end module character_stop_code_test_m

From 79afcc22e07bbe65b943c798a96bf51e49cf283d Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 21:14:48 -0700
Subject: [PATCH 14/18] refac(julienne_m): rm character_stop_code

The character_stop_code subroutine is public only for purposes of
calling it from thetest suite so there's no need to have it in the
public interface (julienne_m).
---
 src/julienne_m.F90                          | 2 +-
 test/modules/character_stop_code_test_m.F90 | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/julienne_m.F90 b/src/julienne_m.F90
index 5b85b6325..1825a9343 100644
--- a/src/julienne_m.F90
+++ b/src/julienne_m.F90
@@ -9,7 +9,7 @@ module julienne_m
   use julienne_file_m, only : file_t
   use julienne_formats_m, only : separated_values, csv
   use julienne_github_ci_m, only : github_ci
-  use julienne_stop_and_print_m, only : stop_and_print, character_stop_code
+  use julienne_stop_and_print_m, only : stop_and_print
   use julienne_string_m, only : string_t, array_of_strings &
     ,operator(.cat.) &
     ,operator(.csv.) &
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index c1fcef974..62d5aaedd 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -484,7 +484,7 @@ function check_string_t_1D_array() result(test_diagnosis)
          expected_stop_code => .csv. messages &
         ,stop_code => character_stop_code(messages) &
       )
-        test_diagnosis = stop_code .equalsExpected. expected_stop_code
+        test_diagnosis = test_diagnosis .also. (stop_code .equalsExpected. expected_stop_code)
       end associate
     end associate
   end function
@@ -499,7 +499,7 @@ function check_file_t() result(test_diagnosis)
          expected_stop_code => file_%lines() .separatedBy. new_line('') &
         ,stop_code => character_stop_code(file_) &
       )
-        test_diagnosis = stop_code .equalsExpected. expected_stop_code
+        test_diagnosis = test_diagnosis .also. (stop_code .equalsExpected. expected_stop_code)
       end associate
     end associate
   end function

From a08eec35ec2d748ca20f6f1ee83500a2be80a6e8 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 22:40:48 -0700
Subject: [PATCH 15/18] feat(character_stop_code): support derived types

This commit supports using user-defined derived-type output (UDDTO)
to create stop codes for derived types that extend the new writable_t
abstract type, which has

- A write_formatted deferred binding that obligates child types to
  support UDDTO,
- A private maxlen_ component that sets the maximum stop-code length,
- A maxlen type-bound function that returns maxlen_, and
- A set_maxlen type-bound subroutine that sets maxlen_.

This commit also includes a corresponding unit test.
---
 src/julienne/julienne_stop_and_print_m.F90  | 49 ++++++++++++++++++++-
 src/julienne_m.F90                          |  2 +-
 test/modules/character_stop_code_test_m.F90 | 42 +++++++++++++++---
 3 files changed, 83 insertions(+), 10 deletions(-)

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index 9f354a8c4..6d99ca719 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -10,22 +10,57 @@ module julienne_stop_and_print_m
   private
   public :: stop_and_print
   public :: character_stop_code
+  public :: writable_t
   
   interface stop_and_print
     module procedure print_string
     module procedure print_header_and_data
   end interface
 
+  type, abstract :: writable_t
+    private
+    integer :: maxlen_ = 16384
+  contains
+    generic :: write(formatted) => write_formatted
+    procedure(write_formatted_i), deferred :: write_formatted
+    procedure :: set_maxlen
+    procedure :: maxlen
+  end type
+
+  abstract interface
+
+    subroutine write_formatted_i(self, unit, edit_descriptor, v_list, iostat, iomsg)
+      import writable_t
+      class(writable_t), intent(in) :: self
+      integer, intent(in) :: unit
+      character(len=*), intent(in) :: edit_descriptor
+      integer, intent(in) :: v_list(:)
+      integer, intent(out) :: iostat
+      character(len=*), intent(inout) :: iomsg
+    end subroutine
+
+  end interface
+
 contains 
 
   pure subroutine print_string(message)
-    implicit none
     type(string_t), intent(in) :: message
     error stop message%string()
   end subroutine
 
+  pure subroutine set_maxlen(self, length)
+    class(writable_t), intent(inout) :: self
+    integer, intent(in) :: length
+    self%maxlen_ = length
+  end subroutine
+
+  pure function maxlen(self) result(length)
+    class(writable_t), intent(in) :: self
+    integer length
+    length = self%maxlen_
+  end function
+
   pure subroutine print_header_and_data(header, data)
-    implicit none
     character(len=*), intent(in) :: header
     class(*), intent(in) :: data
 #ifndef __GFORTRAN__
@@ -68,6 +103,16 @@ pure function character_stop_code(stuff) result(stop_code)
             stop_code = stringy_stuff%string()
           class is(string_t)
             stop_code = stuff%string()
+          class is(writable_t)
+            allocate(character(len=stuff%maxlen()) :: stop_code)
+            block
+              integer io_status
+              write(stop_code,*,iostat=io_status) stuff
+              associate(code_maxlen => string_t(stuff%maxlen()))
+                if (io_status /= 0) error stop "Call writable_t's set_maxlen procedure to increase stop_code maximum size above " // code_maxlen%string()
+              end associate
+            end block
+            stop_code = trim(stop_code)
           class default
              error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for scalar"
         end select
diff --git a/src/julienne_m.F90 b/src/julienne_m.F90
index 1825a9343..3cca68e04 100644
--- a/src/julienne_m.F90
+++ b/src/julienne_m.F90
@@ -9,7 +9,7 @@ module julienne_m
   use julienne_file_m, only : file_t
   use julienne_formats_m, only : separated_values, csv
   use julienne_github_ci_m, only : github_ci
-  use julienne_stop_and_print_m, only : stop_and_print
+  use julienne_stop_and_print_m, only : stop_and_print, writable_t
   use julienne_string_m, only : string_t, array_of_strings &
     ,operator(.cat.) &
     ,operator(.csv.) &
diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index 62d5aaedd..c79e88f47 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -21,7 +21,8 @@ module character_stop_code_test_m
     ,test_diagnosis_t &
     ,test_result_t &
     ,test_t &
-    ,usher
+    ,usher &
+    ,writable_t
   use julienne_stop_and_print_m, only : character_stop_code
 
   implicit none
@@ -39,6 +40,11 @@ module character_stop_code_test_m
     module procedure occurrences_in
   end interface
 
+  type, extends(writable_t) :: write_stuff_t
+  contains
+    procedure :: write_formatted
+  end type
+
 contains
 
   pure function subject() result(specimen)
@@ -52,12 +58,13 @@ function results() result(test_results)
     type(character_stop_code_test_t) character_stop_code_test
 
     test_descriptions = [ &
-       test_description_t(string_t("converting scalars to character stop codes")                                  , usher(check_intrinsic_scalars))   &
-      ,test_description_t(string_t("converting 1D arrays to comma-separated-value (CSV) character stop codes")    , usher(check_intrinsic_1D_arrays)) &
-      ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes")         , usher(check_intrinsic_2D_arrays)) &
-      ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes")         , usher(check_intrinsic_3D_arrays)) &
-      ,test_description_t(string_t("converting a 1D string_t array into a CSV character stop code")               , usher(check_string_t_1D_array))      &
-      ,test_description_t(string_t("converting a file_t object into a new-line-separated character stop code")    , usher(check_file_t))      &
+       test_description_t(string_t("converting scalars to character stop codes")                              , usher(check_intrinsic_scalars))   &
+      ,test_description_t(string_t("converting 1D arrays to comma-separated-value (CSV) character stop codes"), usher(check_intrinsic_1D_arrays)) &
+      ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes")     , usher(check_intrinsic_2D_arrays)) &
+      ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes")     , usher(check_intrinsic_3D_arrays)) &
+      ,test_description_t(string_t("converting a 1D string_t array into a CSV character stop code")           , usher(check_string_t_1D_array))   &
+      ,test_description_t(string_t("converting a file_t object into a new-line-separated character stop code"), usher(check_file_t))              &
+      ,test_description_t(string_t("converting a writable_t child object into character stop code")           , usher(check_writable_t))          &
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function
@@ -504,4 +511,25 @@ function check_file_t() result(test_diagnosis)
     end associate
   end function
 
+  function check_writable_t() result(test_diagnosis)
+    type(test_diagnosis_t) test_diagnosis
+    type(write_stuff_t) write_stuff
+
+    test_diagnosis = passing_test()
+
+    associate(stop_code => character_stop_code(write_stuff))
+      test_diagnosis = stop_code .equalsExpected. "written stuff"
+    end associate
+  end function
+
+  subroutine write_formatted(self, unit, edit_descriptor, v_list, iostat, iomsg)
+    class(write_stuff_t), intent(in) :: self
+    integer, intent(in) :: unit
+    character(len=*), intent(in) :: edit_descriptor
+    integer, intent(in) :: v_list(:)
+    integer, intent(out) :: iostat
+    character(len=*), intent(inout) :: iomsg
+    write(unit,'(a)') "written stuff"
+  end subroutine
+
 end module character_stop_code_test_m

From b053b887f0cdf33645de51be20b79a44738cff49 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 23:01:26 -0700
Subject: [PATCH 16/18] fix: skip 3 tests that crash with gfortran

---
 test/modules/character_stop_code_test_m.F90 | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/test/modules/character_stop_code_test_m.F90 b/test/modules/character_stop_code_test_m.F90
index c79e88f47..5ad5a6f7d 100644
--- a/test/modules/character_stop_code_test_m.F90
+++ b/test/modules/character_stop_code_test_m.F90
@@ -62,9 +62,15 @@ function results() result(test_results)
       ,test_description_t(string_t("converting 1D arrays to comma-separated-value (CSV) character stop codes"), usher(check_intrinsic_1D_arrays)) &
       ,test_description_t(string_t("converting 2D arrays to new-line-separated CSV character stop codes")     , usher(check_intrinsic_2D_arrays)) &
       ,test_description_t(string_t("converting 3D arrays to new-line-separated CSV character stop codes")     , usher(check_intrinsic_3D_arrays)) &
+#ifndef __GFORTRAN__
       ,test_description_t(string_t("converting a 1D string_t array into a CSV character stop code")           , usher(check_string_t_1D_array))   &
       ,test_description_t(string_t("converting a file_t object into a new-line-separated character stop code"), usher(check_file_t))              &
       ,test_description_t(string_t("converting a writable_t child object into character stop code")           , usher(check_writable_t))          &
+#else
+      ,test_description_t(string_t("converting a 1D string_t array into a CSV character stop code")           ) &
+      ,test_description_t(string_t("converting a file_t object into a new-line-separated character stop code")) &
+      ,test_description_t(string_t("converting a writable_t child object into character stop code")           ) &
+#endif
     ]
     test_results = character_stop_code_test%run(test_descriptions)
   end function

From b6a7f80c68f2ec8dbc7c8da9e98f881ca16097e0 Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Sun, 28 Jun 2026 23:15:57 -0700
Subject: [PATCH 17/18] refac(stop_and_print): split {sub,}module

---
 src/julienne/julienne_stop_and_print_m.F90 | 179 ++++-----------------
 src/julienne/julienne_stop_and_print_s.F90 | 142 ++++++++++++++++
 2 files changed, 176 insertions(+), 145 deletions(-)
 create mode 100644 src/julienne/julienne_stop_and_print_s.F90

diff --git a/src/julienne/julienne_stop_and_print_m.F90 b/src/julienne/julienne_stop_and_print_m.F90
index 6d99ca719..c16466782 100644
--- a/src/julienne/julienne_stop_and_print_m.F90
+++ b/src/julienne/julienne_stop_and_print_m.F90
@@ -2,21 +2,15 @@
 ! Terms of use are as specified in LICENSE.txt
 
 module julienne_stop_and_print_m
-  !! Define a pure subroutine subroutine that prints string_t objects/arrays
-  use julienne_string_m, only : string_t, operator(.csv.), operator(.separatedBy.)
-  use julienne_file_m, only : file_t
+  !! Define a pure subroutine that formats and prints various data types during error termination
+  use julienne_string_m, only : string_t
   implicit none
   
   private
   public :: stop_and_print
-  public :: character_stop_code
   public :: writable_t
+  public :: character_stop_code
   
-  interface stop_and_print
-    module procedure print_string
-    module procedure print_header_and_data
-  end interface
-
   type, abstract :: writable_t
     private
     integer :: maxlen_ = 16384
@@ -41,146 +35,41 @@ subroutine write_formatted_i(self, unit, edit_descriptor, v_list, iostat, iomsg)
 
   end interface
 
-contains 
+  interface stop_and_print
 
-  pure subroutine print_string(message)
-    type(string_t), intent(in) :: message
-    error stop message%string()
-  end subroutine
+    pure module subroutine stop_and_print_string(message)
+      implicit none
+      type(string_t), intent(in) :: message
+    end subroutine
 
-  pure subroutine set_maxlen(self, length)
-    class(writable_t), intent(inout) :: self
-    integer, intent(in) :: length
-    self%maxlen_ = length
-  end subroutine
+    pure module subroutine stop_and_print_header_and_data(header, data)
+      implicit none
+      character(len=*), intent(in) :: header
+      class(*), intent(in) :: data
+    end subroutine
 
-  pure function maxlen(self) result(length)
-    class(writable_t), intent(in) :: self
-    integer length
-    length = self%maxlen_
-  end function
+  end interface
 
-  pure subroutine print_header_and_data(header, data)
-    character(len=*), intent(in) :: header
-    class(*), intent(in) :: data
-#ifndef __GFORTRAN__
-    error stop new_line('') // header // new_line('') // character_stop_code(data)
-#else
-    block
-      character(len=:), allocatable :: code
-      code = new_line('') // header // new_line('') // character_stop_code(data)
-      error stop code
-    end block
-#endif
-  end subroutine
+  interface
 
-  pure function character_stop_code(stuff) result(stop_code)
-    class(*), intent(in) :: stuff(..)
-    character(len=:), allocatable :: stop_code
+    pure module subroutine set_maxlen(self, length)
+      implicit none
+      class(writable_t), intent(inout) :: self
+      integer, intent(in) :: length
+    end subroutine
 
-    type(string_t) stringy_stuff
-    integer row, page
+    pure module function maxlen(self) result(length)
+      implicit none
+      class(writable_t), intent(in) :: self
+      integer length
+    end function
 
-    select rank(stuff)
-      rank(0)
-        select type(stuff)
-          type is(character(len=*))
-            stringy_stuff = stuff
-          type is(complex)
-            stringy_stuff = string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(double precision)
-            stringy_stuff = string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(file_t)
-            stringy_stuff = stuff%lines() .separatedBy. new_line('')
-            stop_code = stringy_stuff%string()
-          type is(integer)
-            stringy_stuff = string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(real)
-            stringy_stuff = string_t(stuff)
-            stop_code = stringy_stuff%string()
-          class is(string_t)
-            stop_code = stuff%string()
-          class is(writable_t)
-            allocate(character(len=stuff%maxlen()) :: stop_code)
-            block
-              integer io_status
-              write(stop_code,*,iostat=io_status) stuff
-              associate(code_maxlen => string_t(stuff%maxlen()))
-                if (io_status /= 0) error stop "Call writable_t's set_maxlen procedure to increase stop_code maximum size above " // code_maxlen%string()
-              end associate
-            end block
-            stop_code = trim(stop_code)
-          class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for scalar"
-        end select
-      rank(1)
-        select type(stuff)
-          type is(character(len=*))
-            stringy_stuff = .csv. string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(complex)
-            stringy_stuff = .csv. string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(double precision)
-            stringy_stuff = .csv. string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(integer)
-            stringy_stuff = .csv. string_t(stuff)
-            stop_code = stringy_stuff%string()
-          type is(real)
-            stringy_stuff = .csv. string_t(stuff)
-            stop_code = stringy_stuff%string()
-          class is(string_t)
-            stringy_stuff = .csv. stuff
-            stop_code = stringy_stuff%string()
-          class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-1 array"
-        end select
-      rank(2)
-        select type(stuff)
-          type is(character(len=*))
-            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
-            stop_code = stringy_stuff%string()
-          type is(complex)
-            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
-            stop_code = stringy_stuff%string()
-          type is(double precision)
-            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
-            stop_code = stringy_stuff%string()
-          type is(integer)
-            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
-            stop_code = stringy_stuff%string()
-          type is(real)
-            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
-            stop_code = stringy_stuff%string()
-          class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-2 array"
-        end select
-      rank(3)
-        select type(stuff)
-          type is(complex)
-            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
-            stop_code = stringy_stuff%string()
-          type is(double precision)
-            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
-            stop_code = stringy_stuff%string()
-          type is(integer)
-            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
-            stop_code = stringy_stuff%string()
-          type is(real)
-            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
-            stop_code = stringy_stuff%string()
-          class default
-             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-3 array"
-        end select
-      rank default
-        associate(stop_code_rank => string_t(stop_code))
-          error stop "character_stop_code (in print_and_stop_s): unsupported stop-code rank: " //  stop_code_rank%string()
-        end associate
-    end select
-  end function
-  
-end module
+    pure module function character_stop_code(stuff) result(stop_code)
+      implicit none
+      class(*), intent(in) :: stuff(..)
+      character(len=:), allocatable :: stop_code
+    end function
+
+  end interface
+
+end module julienne_stop_and_print_m
diff --git a/src/julienne/julienne_stop_and_print_s.F90 b/src/julienne/julienne_stop_and_print_s.F90
new file mode 100644
index 000000000..ad6abde9a
--- /dev/null
+++ b/src/julienne/julienne_stop_and_print_s.F90
@@ -0,0 +1,142 @@
+! Copyright (c), The Regents of the University of California and Sourcery Institute
+! Terms of use are as specified in LICENSE.txt
+
+submodule(julienne_stop_and_print_m) julienne_stop_and_print_s
+  use julienne_string_m, only : operator(.csv.), operator(.separatedBy.)
+  use julienne_file_m, only : file_t
+  implicit none
+  
+contains 
+
+  module procedure stop_and_print_string
+    error stop message%string()
+  end procedure
+
+  module procedure set_maxlen
+    self%maxlen_ = length
+  end procedure
+
+  module procedure maxlen
+    length = self%maxlen_
+  end procedure
+
+  module procedure stop_and_print_header_and_data
+#ifndef __GFORTRAN__
+    error stop new_line('') // header // new_line('') // character_stop_code(data)
+#else
+    block
+      character(len=:), allocatable :: code
+      code = new_line('') // header // new_line('') // character_stop_code(data)
+      error stop code
+    end block
+#endif
+  end procedure
+
+  module procedure character_stop_code
+
+    type(string_t) stringy_stuff
+    integer row, page
+
+    select rank(stuff)
+      rank(0)
+        select type(stuff)
+          type is(character(len=*))
+            stringy_stuff = stuff
+          type is(complex)
+            stringy_stuff = string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff = string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(file_t)
+            stringy_stuff = stuff%lines() .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff = string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(real)
+            stringy_stuff = string_t(stuff)
+            stop_code = stringy_stuff%string()
+          class is(string_t)
+            stop_code = stuff%string()
+          class is(writable_t)
+            allocate(character(len=stuff%maxlen()) :: stop_code)
+            block
+              integer io_status
+              write(stop_code,*,iostat=io_status) stuff
+              associate(code_maxlen => string_t(stuff%maxlen()))
+                if (io_status /= 0) error stop "Call writable_t's set_maxlen procedure to increase stop_code maximum size above " // code_maxlen%string()
+              end associate
+            end block
+            stop_code = trim(stop_code)
+          class default
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for scalar"
+        end select
+      rank(1)
+        select type(stuff)
+          type is(character(len=*))
+            stringy_stuff = .csv. string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(complex)
+            stringy_stuff = .csv. string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff = .csv. string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff = .csv. string_t(stuff)
+            stop_code = stringy_stuff%string()
+          type is(real)
+            stringy_stuff = .csv. string_t(stuff)
+            stop_code = stringy_stuff%string()
+          class is(string_t)
+            stringy_stuff = .csv. stuff
+            stop_code = stringy_stuff%string()
+          class default
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-1 array"
+        end select
+      rank(2)
+        select type(stuff)
+          type is(character(len=*))
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
+          type is(complex)
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
+          type is(real)
+            stringy_stuff =  [(.csv. string_t(stuff(row,:)) , row=1,size(stuff,1))] .separatedBy. new_line('')
+            stop_code = stringy_stuff%string()
+          class default
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-2 array"
+        end select
+      rank(3)
+        select type(stuff)
+          type is(complex)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          type is(double precision)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          type is(integer)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          type is(real)
+            stringy_stuff =  [( [(.csv. string_t(stuff(row,:,page)) , row=1,size(stuff,1))] .separatedBy. new_line(''), page = 1,size(stuff,3) )] .separatedBy. (new_line('') // new_line(''))
+            stop_code = stringy_stuff%string()
+          class default
+             error stop "character_stop_code (in print_and_stop_s): unsupported stop-code type for rank-3 array"
+        end select
+      rank default
+        associate(stop_code_rank => string_t(stop_code))
+          error stop "character_stop_code (in print_and_stop_s): unsupported stop-code rank: " //  stop_code_rank%string()
+        end associate
+    end select
+  end procedure
+  
+end submodule julienne_stop_and_print_s

From ba844c9d66cb1c298df20c210e14c3077e847bed Mon Sep 17 00:00:00 2001
From: Damian Rouson <rouson@lbl.gov>
Date: Mon, 29 Jun 2026 00:22:13 -0700
Subject: [PATCH 18/18] doc(README): describe output in pure procedures

---
 README.md | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 644f21e4d..3fa13275c 100644
--- a/README.md
+++ b/README.md
@@ -4,13 +4,34 @@
 
 Julienne: Idiomatic Correctness Checking for Fortran 2023
 =========================================================
-The Julienne framework offers a unified approach to writing unit tests and
-assertions.  Julienne defines idioms for specifying correctness conditions in a
-common in tests that wrap the tested procedures or assertions that conditionally
-execute inside procedures.  Julienne idioms center around expressions built from
+The Julienne framework offers unified approaches to unit testing, assertion
+enforcement, and formatted error-output inside `pure` procedures.  Julienne
+defines idioms for specifying correctness conditions in a common way in tests
+that wrap the tested procedures or assertions that conditionally execute inside
+procedures.  Julienne idioms center around expressions built from
 defined operations: a uniquely flexible Fortran capability allowing developers
 to define _new_ operators or to overloading Fortran's intrinsic operators.
 
+Output in pure procedures
+-------------------------
+Julienne's `stop_and_print` generic interface facilitates automatic or user-defined
+formatting of various data types and ranks inside `pure` procedures via either of two
+specific subroutines:
+
+1. One with a Julienne `string_t` dummy argument and
+2. Another with `character` and unlimited-polymorphic/assumed-rank dummy arugments.
+
+The first subroutine accepts Julienne `string_t` expressions that, for example, convert
+numeric arrays to comma-separated text with `.csv. string_t([1,2,3])`.  The second
+subroutine prints its `character` argument as a header followed by user-formatted or
+automatically-formatted representrations of its polymorphic argument.  Julienne
+automatically formats and prints numeric scalars or arrays up to rank 3.  Users can
+format information for printing by encapsulating the text in a Julienne `file_t` object
+or passing an object, or object wrapper, that extends Julienne's `writable_t` abstract
+type and defines the so-inherited `write(formatted)` generic binding.
+
+Expressive idioms
+-----------------
 Example expressions                                  | Supported operand types
 -----------------------------------------------------|--------------------------------------
 `x .approximates. y .within. tolerance`              | `real`, `double precision` for `x`, `y`, `tolerance`
@@ -38,8 +59,6 @@ where
 * `.equalsExpected.` generates asymmetric diagnostic output for failures, denoting the left- and right-hand sides as the actual value and expected values, respectively; and
 * `//` appends the subsequent string to diagnostics strings, if any.
 
-Expressive idioms
------------------
 ### Assertions
 Any of the above expressions can be the actual argument in an invocation of
 Julienne's `call_julienne_assert` function-line preprocessor macro: