Support the rest of DuckDB's CREATE MACRO syntax

DuckDB's CREATE MACRO also takes `IF NOT EXISTS`, typed parameters (`a INTEGER`),
several overloads (`name (a TINYINT) AS ..., (a INT) AS ...`) and `FUNCTION` as an
alias of `MACRO`. All of these were rejected, and `CREATE FUNCTION f(a) AS a + 1`
was parsed as an opaque `CreateFunction`.

- `CreateMacro` keeps a list of `Overload`s, each with its parameters and body;
  `getParameters()`, `getExpression()`, `getSelect()` and their setters address the
  first one, as before. It also records `IF NOT EXISTS` and the `FUNCTION` keyword,
  and `Parameter` an optional type.
- `CREATE FUNCTION` is routed to `CreateMacro` only when `AS` directly follows the
  parameters and the body is not a string, so PostgreSQL functions
  (`... RETURNS ...`, `... AS $$ ... $$ LANGUAGE ...`) keep their current parse.
- `TablesNamesFinder` visits the queries of every overload.

Author: Jules Ivanic

src/main/java/net/sf/jsqlparser/statement/create/macro/CreateMacro.java

@@ -12,25 +12,33 @@
 import net.sf.jsqlparser.expression.Expression;
 import net.sf.jsqlparser.statement.Statement;
 import net.sf.jsqlparser.statement.StatementVisitor;
+import net.sf.jsqlparser.statement.create.table.ColDataType;
 import net.sf.jsqlparser.statement.select.Select;
 
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Consumer;
 
 /**
- * DuckDB's {@code CREATE [OR REPLACE] [TEMPORARY] MACRO name (parameters) AS [TABLE] body}, a named
- * expression or query that is inlined at call sites.
+ * DuckDB's
+ * {@code CREATE [OR REPLACE] [TEMPORARY] {MACRO | FUNCTION} [IF NOT EXISTS] name (parameters) AS [TABLE] body [, (parameters) AS [TABLE] body ...]},
+ * a named expression or query that is inlined at call sites, optionally overloaded on its
+ * parameters.
+ *
+ * <p>
+ * {@link #getParameters()}, {@link #getExpression()} and {@link #getSelect()} and their setters
+ * address the first overload.
  *
  * @see <a href="https://duckdb.org/docs/stable/sql/statements/create_macro">CREATE MACRO</a>
  */
 public class CreateMacro implements Statement {
     private boolean orReplace;
     private boolean temporary;
+    private boolean functionKeyword;
+    private boolean ifNotExists;
     private String name;
-    private List<Parameter> parameters;
-    private Expression expression;
-    private Select select;
+    private List<Overload> overloads = new ArrayList<>();
 
     public boolean isOrReplace() {
         return orReplace;
@@ -58,6 +66,33 @@ public CreateMacro withTemporary(boolean temporary) {
         return this;
     }
 
+    /** Whether it was written {@code CREATE FUNCTION}, DuckDB's alias of {@code CREATE MACRO}. */
+    public boolean isFunctionKeyword() {
+        return functionKeyword;
+    }
+
+    public void setFunctionKeyword(boolean functionKeyword) {
+        this.functionKeyword = functionKeyword;
+    }
+
+    public CreateMacro withFunctionKeyword(boolean functionKeyword) {
+        setFunctionKeyword(functionKeyword);
+        return this;
+    }
+
+    public boolean isIfNotExists() {
+        return ifNotExists;
+    }
+
+    public void setIfNotExists(boolean ifNotExists) {
+        this.ifNotExists = ifNotExists;
+    }
+
+    public CreateMacro withIfNotExists(boolean ifNotExists) {
+        setIfNotExists(ifNotExists);
+        return this;
+    }
+
     public String getName() {
         return name;
     }
@@ -71,12 +106,32 @@ public CreateMacro withName(String name) {
         return this;
     }
 
+    public List<Overload> getOverloads() {
+        return overloads;
+    }
+
+    public void setOverloads(List<Overload> overloads) {
+        this.overloads = overloads;
+    }
+
+    public CreateMacro withOverloads(List<Overload> overloads) {
+        setOverloads(overloads);
+        return this;
+    }
+
+    private Overload firstOverload() {
+        if (overloads.isEmpty()) {
+            overloads.add(new Overload());
+        }
+        return overloads.get(0);
+    }
+
     public List<Parameter> getParameters() {
-        return parameters;
+        return overloads.isEmpty() ? null : overloads.get(0).getParameters();
     }
 
     public void setParameters(List<Parameter> parameters) {
-        this.parameters = parameters;
+        firstOverload().setParameters(parameters);
     }
 
     public CreateMacro withParameters(List<Parameter> parameters) {
@@ -85,11 +140,11 @@ public CreateMacro withParameters(List<Parameter> parameters) {
     }
 
     public Expression getExpression() {
-        return expression;
+        return overloads.isEmpty() ? null : overloads.get(0).getExpression();
     }
 
     public void setExpression(Expression expression) {
-        this.expression = expression;
+        firstOverload().setExpression(expression);
     }
 
     public CreateMacro withExpression(Expression expression) {
@@ -98,11 +153,11 @@ public CreateMacro withExpression(Expression expression) {
     }
 
     public Select getSelect() {
-        return select;
+        return overloads.isEmpty() ? null : overloads.get(0).getSelect();
     }
 
     public void setSelect(Select select) {
-        this.select = select;
+        firstOverload().setSelect(select);
     }
 
     public CreateMacro withSelect(Select select) {
@@ -112,7 +167,7 @@ public CreateMacro withSelect(Select select) {
 
     /** A table macro returns a relation, a scalar macro an expression. */
     public boolean isTable() {
-        return select != null;
+        return getSelect() != null;
     }
 
     public StringBuilder appendTo(StringBuilder builder) {
@@ -129,19 +184,16 @@ public StringBuilder appendTo(StringBuilder builder, Consumer<Expression> expres
         if (temporary) {
             builder.append("TEMPORARY ");
         }
-        builder.append("MACRO ").append(name).append(" (");
-        for (int i = 0; i < parameters.size(); i++) {
+        builder.append(functionKeyword ? "FUNCTION " : "MACRO ");
+        if (ifNotExists) {
+            builder.append("IF NOT EXISTS ");
+        }
+        builder.append(name).append(" ");
+        for (int i = 0; i < overloads.size(); i++) {
             if (i > 0) {
                 builder.append(", ");
             }
-            parameters.get(i).appendTo(builder, expressionRenderer);
-        }
-        builder.append(") AS ");
-        if (select != null) {
-            builder.append("TABLE ");
-            selectRenderer.accept(select);
-        } else {
-            expressionRenderer.accept(expression);
+            overloads.get(i).appendTo(builder, expressionRenderer, selectRenderer);
         }
         return builder;
     }
@@ -156,24 +208,113 @@ public <T, S> T accept(StatementVisitor<T> statementVisitor, S context) {
         return statementVisitor.visit(this, context);
     }
 
-    /** A macro parameter, optionally carrying a default value ({@code b := 5}). */
+    /** One {@code (parameters) AS [TABLE] body} of a macro. */
+    public static class Overload implements Serializable {
+        private List<Parameter> parameters = new ArrayList<>();
+        private Expression expression;
+        private Select select;
+
+        public List<Parameter> getParameters() {
+            return parameters;
+        }
+
+        public void setParameters(List<Parameter> parameters) {
+            this.parameters = parameters;
+        }
+
+        public Overload withParameters(List<Parameter> parameters) {
+            setParameters(parameters);
+            return this;
+        }
+
+        public Expression getExpression() {
+            return expression;
+        }
+
+        public void setExpression(Expression expression) {
+            this.expression = expression;
+        }
+
+        public Overload withExpression(Expression expression) {
+            setExpression(expression);
+            return this;
+        }
+
+        public Select getSelect() {
+            return select;
+        }
+
+        public void setSelect(Select select) {
+            this.select = select;
+        }
+
+        public Overload withSelect(Select select) {
+            setSelect(select);
+            return this;
+        }
+
+        /** A table overload returns a relation, a scalar one an expression. */
+        public boolean isTable() {
+            return select != null;
+        }
+
+        @Override
+        public String toString() {
+            StringBuilder builder = new StringBuilder();
+            return appendTo(builder, builder::append, builder::append).toString();
+        }
+
+        private StringBuilder appendTo(StringBuilder builder,
+                Consumer<Expression> expressionRenderer, Consumer<Select> selectRenderer) {
+            builder.append("(");
+            for (int i = 0; i < parameters.size(); i++) {
+                if (i > 0) {
+                    builder.append(", ");
+                }
+                parameters.get(i).appendTo(builder, expressionRenderer);
+            }
+            builder.append(") AS ");
+            if (select != null) {
+                builder.append("TABLE ");
+                selectRenderer.accept(select);
+            } else {
+                expressionRenderer.accept(expression);
+            }
+            return builder;
+        }
+    }
+
+    /**
+     * A macro parameter, optionally typed ({@code a INTEGER}) and carrying a default value
+     * ({@code b := 5}).
+     */
     public static class Parameter implements Serializable {
         private final String name;
+        private final ColDataType type;
         private final Expression defaultValue;
 
         public Parameter(String name) {
-            this(name, null);
+            this(name, null, null);
         }
 
         public Parameter(String name, Expression defaultValue) {
+            this(name, null, defaultValue);
+        }
+
+        public Parameter(String name, ColDataType type, Expression defaultValue) {
             this.name = name;
+            this.type = type;
             this.defaultValue = defaultValue;
         }
 
         public String getName() {
             return name;
         }
 
+        public ColDataType getType() {
+            return type;
+        }
+
         public Expression getDefaultValue() {
             return defaultValue;
         }
@@ -187,6 +328,9 @@ public String toString() {
         private StringBuilder appendTo(StringBuilder builder,
                 Consumer<Expression> expressionRenderer) {
             builder.append(name);
+            if (type != null) {
+                builder.append(" ").append(type);
+            }
             if (defaultValue != null) {
                 builder.append(" := ");
                 expressionRenderer.accept(defaultValue);

src/main/java/net/sf/jsqlparser/util/TablesNamesFinder.java

@@ -2722,8 +2722,10 @@ public void visit(CopyStatement copyStatement) {
 
     @Override
     public <S> Void visit(CreateMacro createMacro, S context) {
-        if (createMacro.getSelect() != null) {
-            createMacro.getSelect().accept((SelectVisitor<?>) this, context);
+        for (CreateMacro.Overload overload : createMacro.getOverloads()) {
+            if (overload.getSelect() != null) {
+                overload.getSelect().accept((SelectVisitor<?>) this, context);
+            }
         }
         return null;
     }