cel-expr · copybara-service · Jul 30, 2025 · Jul 30, 2025
diff --git a/bundle/src/main/java/dev/cel/bundle/CelEnvironmentExporter.java b/bundle/src/main/java/dev/cel/bundle/CelEnvironmentExporter.java
@@ -113,6 +113,7 @@ public abstract static class Builder {
    @CanIgnoreReturnValue
    public Builder addStandardExtensions(CelOptions options) {
      addExtensionLibraries(
+          CelExtensions.getExtensionLibrary("bindings", options),
          CelExtensions.getExtensionLibrary("math", options),
          CelExtensions.getExtensionLibrary("lists", options));
      // TODO: add support for remaining standard extensions

diff --git a/extensions/src/main/java/dev/cel/extensions/BUILD.bazel b/extensions/src/main/java/dev/cel/extensions/BUILD.bazel
@@ -138,6 +138,7 @@ java_library(
        "//common:compiler_common",
        "//common/ast",
        "//compiler:compiler_builder",
+        "//extensions:extension_library",
        "//parser:macro",
        "//parser:parser_builder",
        "@maven//:com_google_errorprone_error_prone_annotations",

diff --git a/extensions/src/main/java/dev/cel/extensions/CelBindingsExtensions.java b/extensions/src/main/java/dev/cel/extensions/CelBindingsExtensions.java
@@ -18,7 +18,9 @@
 import static com.google.common.base.Preconditions.checkNotNull;

 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import com.google.errorprone.annotations.Immutable;
+import dev.cel.common.CelFunctionDecl;
 import dev.cel.common.CelIssue;
 import dev.cel.common.ast.CelExpr;
 import dev.cel.compiler.CelCompilerLibrary;
@@ -29,15 +31,47 @@

 /** Internal implementation of the CEL local binding extensions. */
 @Immutable
-final class CelBindingsExtensions implements CelCompilerLibrary {
-
+final class CelBindingsExtensions implements CelCompilerLibrary, CelExtensionLibrary.FeatureSet {
  private static final String CEL_NAMESPACE = "cel";
  private static final String UNUSED_ITER_VAR = "#unused";

+  private static final CelExtensionLibrary<CelBindingsExtensions> LIBRARY =
+      new CelExtensionLibrary<CelBindingsExtensions>() {
+        private final CelBindingsExtensions version0 = new CelBindingsExtensions();
+
+        @Override
+        public String name() {
+          return "bindings";
+        }
+
+        @Override
+        public ImmutableSet<CelBindingsExtensions> versions() {
+          return ImmutableSet.of(version0);
+        }
+      };
+
+  static CelExtensionLibrary<CelBindingsExtensions> library() {
+    return LIBRARY;
+  }
+
+  @Override
+  public int version() {
+    return 0;
+  }
+
+  @Override
+  public ImmutableSet<CelFunctionDecl> functions() {
+    return ImmutableSet.of();
+  }
+
+  @Override
+  public ImmutableSet<CelMacro> macros() {
+    return ImmutableSet.of(CelMacro.newReceiverMacro("bind", 3, CelBindingsExtensions::expandBind));
+  }
+
  @Override
  public void setParserOptions(CelParserBuilder parserBuilder) {
-    parserBuilder.addMacros(
-        CelMacro.newReceiverMacro("bind", 3, CelBindingsExtensions::expandBind));
+    parserBuilder.addMacros(macros());
  }

  /**

diff --git a/extensions/src/main/java/dev/cel/extensions/CelExtensions.java b/extensions/src/main/java/dev/cel/extensions/CelExtensions.java
@@ -303,6 +303,8 @@ public static ImmutableSet<String> getAllFunctionNames() {
  public static CelExtensionLibrary<? extends CelExtensionLibrary.FeatureSet> getExtensionLibrary(
      String name, CelOptions options) {
    switch (name) {
+      case "bindings":
+        return CelBindingsExtensions.library();
      case "math":
        return CelMathExtensions.library(options);
      case "lists":

diff --git a/extensions/src/test/java/dev/cel/extensions/BUILD.bazel b/extensions/src/test/java/dev/cel/extensions/BUILD.bazel
@@ -20,6 +20,7 @@ java_library(
        "//compiler",
        "//compiler:compiler_builder",
        "//extensions",
+        "//extensions:extension_library",
        "//extensions:lite_extensions",
        "//extensions:math",
        "//extensions:optional_library",

diff --git a/extensions/src/test/java/dev/cel/extensions/CelBindingsExtensionsTest.java b/extensions/src/test/java/dev/cel/extensions/CelBindingsExtensionsTest.java
@@ -24,13 +24,15 @@
 import com.google.testing.junit.testparameterinjector.TestParameters;
 import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelFunctionDecl;
+import dev.cel.common.CelOptions;
 import dev.cel.common.CelOverloadDecl;
 import dev.cel.common.CelValidationException;
 import dev.cel.common.types.SimpleType;
 import dev.cel.common.types.StructTypeReference;
 import dev.cel.compiler.CelCompiler;
 import dev.cel.compiler.CelCompilerFactory;
 import dev.cel.expr.conformance.proto3.TestAllTypes;
+import dev.cel.parser.CelMacro;
 import dev.cel.parser.CelStandardMacro;
 import dev.cel.runtime.CelFunctionBinding;
 import dev.cel.runtime.CelRuntime;
@@ -54,6 +56,17 @@ public final class CelBindingsExtensionsTest {
          .addLibraries(CelOptionalLibrary.INSTANCE)
          .build();

+  @Test
+  public void library() {
+    CelExtensionLibrary<?> library =
+        CelExtensions.getExtensionLibrary("bindings", CelOptions.DEFAULT);
+    assertThat(library.name()).isEqualTo("bindings");
+    assertThat(library.latest().version()).isEqualTo(0);
+    assertThat(library.version(0).functions()).isEmpty();
+    assertThat(library.version(0).macros().stream().map(CelMacro::getFunction))
+        .containsExactly("bind");
+  }
+
  private enum BindingTestCase {
    BOOL_LITERAL("cel.bind(t, true, t)"),
    STRING_CONCAT("cel.bind(msg, \"hello\", msg + msg + msg) == \"hellohellohello\""),