Group overloads to a single function to facilitate dynamic dispatch

runtime/src/main/java/dev/cel/runtime/BUILD.bazel

@@ -122,6 +122,7 @@ java_library(
     deps = [
         ":evaluation_exception",
         ":evaluation_exception_builder",
+        ":function_binding",
         ":function_overload",
         ":function_resolver",
         ":resolved_overload",
@@ -141,6 +142,7 @@ cel_android_library(
     deps = [
         ":evaluation_exception",
         ":evaluation_exception_builder",
+        ":function_binding_android",
         ":function_overload_android",
         ":function_resolver_android",
         ":resolved_overload_android",
@@ -609,6 +611,7 @@ java_library(
     deps = [
         ":function_binding",
         ":runtime_equality",
+        "//common:operator",
         "//common:options",
         "//common/annotations",
         "//runtime/standard:add",
@@ -666,6 +669,7 @@ cel_android_library(
     deps = [
         ":function_binding_android",
         ":runtime_equality_android",
+        "//common:operator_android",
         "//common:options",
         "//common/annotations",
         "//runtime/standard:add_android",
@@ -723,6 +727,7 @@ java_library(
     tags = [
     ],
     deps = [
+        ":evaluation_exception",
         ":function_overload",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_guava_guava",
@@ -735,6 +740,7 @@ cel_android_library(
     tags = [
     ],
     deps = [
+        ":evaluation_exception",
         ":function_overload_android",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven_android//:com_google_guava_guava",
@@ -774,7 +780,9 @@ java_library(
     ],
     deps = [
         ":evaluation_exception",
+        "//runtime:unknown_attributes",
         "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven//:com_google_guava_guava",
     ],
 )
 
@@ -785,7 +793,9 @@ cel_android_library(
     ],
     deps = [
         ":evaluation_exception",
+        "//runtime:unknown_attributes_android",
         "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven_android//:com_google_guava_guava",
     ],
 )
 
@@ -1173,7 +1183,6 @@ java_library(
     ],
     deps = [
         ":function_overload",
-        ":unknown_attributes",
         "//:auto_value",
         "//common/annotations",
         "@maven//:com_google_errorprone_error_prone_annotations",
@@ -1188,7 +1197,6 @@ cel_android_library(
     ],
     deps = [
         ":function_overload_android",
-        ":unknown_attributes_android",
         "//:auto_value",
         "//common/annotations",
         "@maven//:com_google_errorprone_error_prone_annotations",

runtime/src/main/java/dev/cel/runtime/CelFunctionBinding.java

@@ -14,8 +14,13 @@
 
 package dev.cel.runtime;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
+import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.annotations.Immutable;
+import java.util.Collection;
 
 /**
  * Binding consisting of an overload id, a Java-native argument signature, and an overload
@@ -35,7 +40,6 @@
  *
  * <p>Examples: string_startsWith_string, mathMax_list, lessThan_money_money
  */
-
 @Immutable
 public interface CelFunctionBinding {
   String getOverloadId();
@@ -70,4 +74,23 @@ static CelFunctionBinding from(
     return new FunctionBindingImpl(
         overloadId, ImmutableList.copyOf(argTypes), impl, /* isStrict= */ true);
   }
+
+  /** See {@link #fromOverloads(String, Collection)}. */
+  static ImmutableSet<CelFunctionBinding> fromOverloads(
+      String functionName, CelFunctionBinding... overloadBindings) {
+    return fromOverloads(functionName, ImmutableList.copyOf(overloadBindings));
+  }
+
+  /**
+   * Creates a set of bindings for a function, enabling dynamic dispatch logic to select the correct
+   * overload at runtime based on argument types.
+   */
+  static ImmutableSet<CelFunctionBinding> fromOverloads(
+      String functionName, Collection<CelFunctionBinding> overloadBindings) {
+    checkArgument(!Strings.isNullOrEmpty(functionName), "Function name cannot be null or empty");
+    checkArgument(!overloadBindings.isEmpty(), "You must provide at least one binding.");
+
+    return FunctionBindingImpl.groupOverloadsToFunction(
+        functionName, ImmutableSet.copyOf(overloadBindings));
+  }
 }

runtime/src/main/java/dev/cel/runtime/CelFunctionOverload.java

@@ -14,7 +14,9 @@
 
 package dev.cel.runtime;
 
+import com.google.common.collect.ImmutableList;
 import com.google.errorprone.annotations.Immutable;
+import java.util.Map;
 
 /** Interface describing the general signature of all CEL custom function implementations. */
 @Immutable
@@ -43,4 +45,39 @@ interface Unary<T> {
   interface Binary<T1, T2> {
     Object apply(T1 arg1, T2 arg2) throws CelEvaluationException;
   }
+
+  /**
+   * Returns true if the overload's expected argument types match the types of the given arguments.
+   */
+  static boolean canHandle(
+      Object[] arguments, ImmutableList<Class<?>> parameterTypes, boolean isStrict) {
+    if (parameterTypes.size() != arguments.length) {
+      return false;
+    }
+    for (int i = 0; i < parameterTypes.size(); i++) {
+      Class<?> paramType = parameterTypes.get(i);
+      Object arg = arguments[i];
+      if (arg == null) {
+        // null can be assigned to messages, maps, and to objects.
+        // TODO: Remove null special casing
+        if (paramType != Object.class && !Map.class.isAssignableFrom(paramType)) {
+          return false;
+        }
+        continue;
+      }
+
+      if (arg instanceof Exception || arg instanceof CelUnknownSet) {
+        // Only non-strict functions can accept errors/unknowns as arguments to a function
+        if (!isStrict) {
+          // Skip assignability check below, but continue to validate remaining args
+          continue;
+        }
+      }
+
+      if (!paramType.isAssignableFrom(arg.getClass())) {
+        return false;
+      }
+    }
+    return true;
+  }
 }

runtime/src/main/java/dev/cel/runtime/CelResolvedOverload.java

@@ -19,7 +19,6 @@
 import com.google.errorprone.annotations.Immutable;
 import dev.cel.common.annotations.Internal;
 import java.util.List;
-import java.util.Map;
 
 /**
  * Representation of a function overload which has been resolved to a specific set of argument types
@@ -80,41 +79,6 @@ public static CelResolvedOverload of(
    * Returns true if the overload's expected argument types match the types of the given arguments.
    */
   boolean canHandle(Object[] arguments) {
-    return canHandle(arguments, getParameterTypes(), isStrict());
-  }
-
-  /**
-   * Returns true if the overload's expected argument types match the types of the given arguments.
-   */
-  public static boolean canHandle(
-      Object[] arguments, ImmutableList<Class<?>> parameterTypes, boolean isStrict) {
-    if (parameterTypes.size() != arguments.length) {
-      return false;
-    }
-    for (int i = 0; i < parameterTypes.size(); i++) {
-      Class<?> paramType = parameterTypes.get(i);
-      Object arg = arguments[i];
-      if (arg == null) {
-        // null can be assigned to messages, maps, and to objects.
-        // TODO: Remove null special casing
-        if (paramType != Object.class && !Map.class.isAssignableFrom(paramType)) {
-          return false;
-        }
-        continue;
-      }
-
-      if (arg instanceof Exception || arg instanceof CelUnknownSet) {
-        // Only non-strict functions can accept errors/unknowns as arguments to a function
-        if (!isStrict) {
-          // Skip assignability check below, but continue to validate remaining args
-          continue;
-        }
-      }
-
-      if (!paramType.isAssignableFrom(arg.getClass())) {
-        return false;
-      }
-    }
-    return true;
+    return CelFunctionOverload.canHandle(arguments, getParameterTypes(), isStrict());
   }
 }