Add []string support to risor-modgen (#167)

cmd/risor-modgen/func.go

@@ -113,23 +113,20 @@ func (m *Module) parseFuncDeclName(decl *ast.FuncDecl) (string, error) {
 }
 
 func (m *Module) parseFuncDeclParam(name string, param *ast.Field) (FuncParam, error) {
-	switch expr := param.Type.(type) {
-	case *ast.Ident:
-		p, err := m.parseParamType(expr.Name)
-		if err != nil {
-			return FuncParam{}, err
-		}
-		p.Name = name
-		return p, nil
-	default:
-		return FuncParam{}, fmt.Errorf("unsupported parameter expression type: %T", param.Type)
+	p, err := m.parseParamType(m.sprintExpr(param.Type))
+	if err != nil {
+		return FuncParam{}, err
 	}
+	p.Name = name
+	return p, nil
 }
 
 func (m *Module) parseParamType(typeName string) (FuncParam, error) {
 	switch typeName {
 	case "string":
 		return FuncParam{ReadFunc: "AsString"}, nil
+	case "[]string":
+		return FuncParam{ReadFunc: "AsStringSlice"}, nil
 	case "bool":
 		return FuncParam{ReadFunc: "AsBool"}, nil
 	case "int64":
@@ -151,22 +148,19 @@ func (m *Module) parseParamType(typeName string) (FuncParam, error) {
 }
 
 func (m *Module) parseFuncDeclReturn(ret *ast.Field) (FuncReturn, error) {
-	switch expr := ret.Type.(type) {
-	case *ast.Ident:
-		p, err := m.parseReturnType(expr.Name)
-		if err != nil {
-			return FuncReturn{}, err
-		}
-		return p, nil
-	default:
-		return FuncReturn{}, fmt.Errorf("unsupported return expression type: %T", ret.Type)
+	p, err := m.parseReturnType(m.sprintExpr(ret.Type))
+	if err != nil {
+		return FuncReturn{}, err
 	}
+	return p, nil
 }
 
 func (m *Module) parseReturnType(typeName string) (FuncReturn, error) {
 	switch typeName {
 	case "string":
 		return FuncReturn{NewFunc: "NewString"}, nil
+	case "[]string":
+		return FuncReturn{NewFunc: "NewStringList"}, nil
 	case "bool":
 		return FuncReturn{NewFunc: "NewBool"}, nil
 	case "int64":

cmd/risor-modgen/main.go

@@ -1,11 +1,13 @@
 package main
 
 import (
+	"bytes"
 	"crypto/sha512"
 	"flag"
 	"fmt"
 	"go/ast"
 	"go/parser"
+	"go/printer"
 	"go/token"
 	"io"
 	"io/fs"
@@ -344,6 +346,12 @@ func (m *Module) addImport(pkg string) {
 	}
 }
 
+func (m *Module) sprintExpr(node any) string {
+	var buf bytes.Buffer
+	printer.Fprint(&buf, m.fset, node)
+	return buf.String()
+}
+
 func cutPrefixAndSpace(s, prefix string) (after string, ok bool) {
 	after, ok = strings.CutPrefix(s, prefix)
 	if !ok {

modules/strings/strings.go

@@ -1,22 +1,10 @@
 package strings
 
 import (
-	"context"
 	"strings"
-
-	"github.com/risor-io/risor/internal/arg"
-	"github.com/risor-io/risor/object"
 )
 
-//risor:generate no-module-func
-
-func asString(obj object.Object) (*object.String, *object.Error) {
-	s, ok := obj.(*object.String)
-	if !ok {
-		return nil, object.Errorf("type error: expected a string (got %v)", obj.Type())
-	}
-	return s, nil
-}
+//risor:generate
 
 //risor:export
 func contains(s, substr string) bool {
@@ -48,41 +36,19 @@ func repeat(s string, count int) string {
 	return strings.Repeat(s, count)
 }
 
-func Join(ctx context.Context, args ...object.Object) object.Object {
-	if err := arg.Require("strings.join", 2, args); err != nil {
-		return err
-	}
-	list, err := object.AsList(args[0])
-	if err != nil {
-		return err
-	}
-	sep, err := asString(args[1])
-	if err != nil {
-		return err
-	}
-	return sep.Join(list)
-}
-
-func Split(ctx context.Context, args ...object.Object) object.Object {
-	if err := arg.Require("strings.split", 2, args); err != nil {
-		return err
-	}
-	s, err := asString(args[0])
-	if err != nil {
-		return err
-	}
-	return s.Split(args[1])
-}
-
-func Fields(ctx context.Context, args ...object.Object) object.Object {
-	if err := arg.Require("strings.fields", 1, args); err != nil {
-		return err
-	}
-	s, err := asString(args[0])
-	if err != nil {
-		return err
-	}
-	return s.Fields()
+//risor:export
+func join(list []string, sep string) string {
+	return strings.Join(list, sep)
+}
+
+//risor:export
+func split(s, sep string) []string {
+	return strings.Split(s, sep)
+}
+
+//risor:export
+func fields(s string) []string {
+	return strings.Fields(s)
 }
 
 //risor:export
@@ -129,11 +95,3 @@ func trimSuffix(s, prefix string) string {
 func trimSpace(s string) string {
 	return strings.TrimSpace(s)
 }
-
-func Module() *object.Module {
-	return object.NewBuiltinsModule("strings", addGeneratedBuiltins(map[string]object.Object{
-		"fields": object.NewBuiltin("fields", Fields),
-		"join":   object.NewBuiltin("join", Join),
-		"split":  object.NewBuiltin("split", Split),
-	}))
-}