Init function bindings on environment init (#1199)

beldmian · web-flow · commit fb02c9a55d96 · 2025-07-25T12:02:54.000-07:00
* Init function bindings on environment init

* Move calculation of function bindings under sync.Once call in new program creation
diff --git a/cel/env.go b/cel/env.go
@@ -27,6 +27,7 @@ import (
 	"github.com/google/cel-go/common/containers"
 	"github.com/google/cel-go/common/decls"
 	"github.com/google/cel-go/common/env"
+	"github.com/google/cel-go/common/functions"
 	"github.com/google/cel-go/common/stdlib"
 	"github.com/google/cel-go/common/types"
 	"github.com/google/cel-go/common/types/ref"
@@ -142,6 +143,9 @@ type Env struct {
 	validators      []ASTValidator
 	costOptions     []checker.CostOption
 
+	funcBindOnce     sync.Once
+	functionBindings []*functions.Overload
+
 	// Internal parser representation
 	prsr     *parser.Parser
 	prsrOpts []parser.Option
@@ -320,18 +324,19 @@ func NewCustomEnv(opts ...EnvOption) (*Env, error) {
 		return nil, err
 	}
 	return (&Env{
-		variables:       []*decls.VariableDecl{},
-		functions:       map[string]*decls.FunctionDecl{},
-		macros:          []parser.Macro{},
-		Container:       containers.DefaultContainer,
-		adapter:         registry,
-		provider:        registry,
-		features:        map[int]bool{},
-		appliedFeatures: map[int]bool{},
-		libraries:       map[string]SingletonLibrary{},
-		validators:      []ASTValidator{},
-		progOpts:        []ProgramOption{},
-		costOptions:     []checker.CostOption{},
+		variables:        []*decls.VariableDecl{},
+		functions:        map[string]*decls.FunctionDecl{},
+		functionBindings: []*functions.Overload{},
+		macros:           []parser.Macro{},
+		Container:        containers.DefaultContainer,
+		adapter:          registry,
+		provider:         registry,
+		features:         map[int]bool{},
+		appliedFeatures:  map[int]bool{},
+		libraries:        map[string]SingletonLibrary{},
+		validators:       []ASTValidator{},
+		progOpts:         []ProgramOption{},
+		costOptions:      []checker.CostOption{},
 	}).configure(opts)
 }
 
diff --git a/cel/program.go b/cel/program.go
@@ -20,6 +20,7 @@ import (
 	"sync"
 
 	"github.com/google/cel-go/common/ast"
+	"github.com/google/cel-go/common/functions"
 	"github.com/google/cel-go/common/types"
 	"github.com/google/cel-go/common/types/ref"
 	"github.com/google/cel-go/interpreter"
@@ -191,16 +192,25 @@ func newProgram(e *Env, a *ast.AST, opts []ProgramOption) (Program, error) {
 		}
 	}
 
-	// Add the function bindings created via Function() options.
-	for _, fn := range e.functions {
-		bindings, err := fn.Bindings()
-		if err != nil {
-			return nil, err
-		}
-		err = disp.Add(bindings...)
-		if err != nil {
-			return nil, err
+	e.funcBindOnce.Do(func() {
+		var bindings []*functions.Overload
+		e.functionBindings = []*functions.Overload{}
+		for _, fn := range e.functions {
+			bindings, err = fn.Bindings()
+			if err != nil {
+				return
+			}
+			e.functionBindings = append(e.functionBindings, bindings...)
 		}
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// Add the function bindings created via Function() options.
+	err = disp.Add(e.functionBindings...)
+	if err != nil {
+		return nil, err
 	}
 
 	// Set the attribute factory after the options have been set.
