ext: add overloads for the individual comparable types

ext/README.md

@@ -408,8 +408,10 @@ Examples:
 ### Sort
 
 Sorts a list with comparable elements. If the element type is not comparable
+or the element types are not the same, the function will produce an error.
 
     <list(T)>.sort() -> <list(T)>
+    T in {int, uint, double, bool, duration, timestamp, string, bytes}
 
 Examples:
 

ext/lists.go

@@ -59,8 +59,10 @@ import (
 // # Sort
 //
 // Sorts a list with comparable elements. If the element type is not comparable
+// or the element types are not the same, the function will produce an error.
 //
 //	<list(T)>.sort() -> <list(T)>
+//	T in {int, uint, double, bool, duration, timestamp, string, bytes}
 //
 // Examples:
 //
@@ -108,6 +110,25 @@ func ListsVersion(version uint32) ListsOption {
 	}
 }
 
+var comparableTypes = []*cel.Type{
+	cel.IntType,
+	cel.UintType,
+	cel.DoubleType,
+	cel.BoolType,
+	cel.DurationType,
+	cel.TimestampType,
+	cel.StringType,
+	cel.BytesType,
+}
+
+func templatedOverloads(types []*cel.Type, template func(t *cel.Type) cel.FunctionOpt) []cel.FunctionOpt {
+	overloads := make([]cel.FunctionOpt, len(types))
+	for i, t := range types {
+		overloads[i] = template(t)
+	}
+	return overloads
+}
+
 // CompileOptions implements the Library interface method.
 func (lib listsLib) CompileOptions() []cel.EnvOption {
 	listType := cel.ListType(cel.TypeParamType("T"))
@@ -175,10 +196,11 @@ func (lib listsLib) CompileOptions() []cel.EnvOption {
 		)
 	}
 	if lib.version >= 2 {
-		opts = append(opts,
-			cel.Function("sort",
-				cel.MemberOverload("list_sort",
-					[]*cel.Type{listType}, listType,
+		sortDecl := cel.Function("sort",
+			templatedOverloads(comparableTypes, func(t *cel.Type) cel.FunctionOpt {
+				return cel.MemberOverload(
+					fmt.Sprintf("list_%s_sort", t.TypeName()),
+					[]*cel.Type{cel.ListType(t)}, cel.ListType(t),
 					cel.UnaryBinding(func(arg ref.Val) ref.Val {
 						list, ok := arg.(traits.Lister)
 						if !ok {
@@ -191,9 +213,10 @@ func (lib listsLib) CompileOptions() []cel.EnvOption {
 
 						return sorted
 					}),
-				),
-			),
+				)
+			})...,
 		)
+		opts = append(opts, sortDecl)
 	}
 
 	return opts

ext/lists_test.go

@@ -45,8 +45,6 @@ func TestLists(t *testing.T) {
 		{expr: `[4, 3, 2, 1].sort() == [1, 2, 3, 4]`},
 		{expr: `["d", "a", "b", "c"].sort() == ["a", "b", "c", "d"]`},
 		{expr: `["d", 3, 2, "c"].sort() == ["a", "b", "c", "d"]`, err: "list elements must have the same type"},
-		{expr: `[[1, 2, 3], [3, 2, 1]].sort()`, err: "list elements must be comparable"},
-		{expr: `[[1, 2, 3]].sort()`, err: "list elements must be comparable"},
 	}
 
 	env := testListsEnv(t)