lang: funcs: funcgen: Allow []string as inputs

This allows us to have the strings.Join function generated.

lang/funcs/funcgen/config.go

@@ -19,6 +19,7 @@ package main
 
 import (
 	"fmt"
+	"math/bits"
 
 	"github.com/purpleidea/mgmt/lang/types"
 )
@@ -63,6 +64,8 @@ func (obj *arg) ToMcl() (string, error) {
 		return fmt.Sprintf("%s%s", prefix, types.TypeInt.String()), nil
 	case "float64":
 		return fmt.Sprintf("%s%s", prefix, types.TypeFloat.String()), nil
+	case "[]string":
+		return fmt.Sprintf("%s%s", prefix, types.NewType("[]str").String()), nil
 	default:
 		return "", fmt.Errorf("cannot convert %v to mcl", obj.Type)
 	}
@@ -87,6 +90,37 @@ func (obj *arg) OldToGolang() (string, error) {
 	}
 }
 
+// ToGolang prints the arg signature as expected by golang.
+func (obj *arg) ToGolang(val string) (string, error) {
+	switch obj.Type {
+	case "bool":
+		return fmt.Sprintf("%s.Bool()", val), nil
+
+	case "string", "[]byte":
+		return fmt.Sprintf("%s.Str()", val), nil
+
+	case "int":
+		// TODO: consider switching types.Value int64 to int everywhere
+		if bits.UintSize == 32 { // special case for 32 bit golang
+			return fmt.Sprintf("int(%s.Int())", val), nil
+		}
+		fallthrough
+	case "int64":
+		return fmt.Sprintf("%s.Int()", val), nil
+
+	case "float64":
+		return fmt.Sprintf("%s.Float()", val), nil
+
+	case "[]string":
+		// This function is in the child util package and is imported by
+		// the template.
+		return fmt.Sprintf("util.MclListToGolang(%s)", val), nil
+
+	default:
+		return "", fmt.Errorf("cannot convert %v to golang", obj)
+	}
+}
+
 // ToTestInput prints the arg signature as expected by tests.
 func (obj *arg) ToTestInput() (string, error) {
 	switch obj.Type {

lang/funcs/funcgen/fixtures/func_base.tpl

@@ -20,6 +20,7 @@ package core
 import (
 	"testpkg"
 
+	"github.com/purpleidea/mgmt/lang/funcs/funcgen/util"
 	"github.com/purpleidea/mgmt/lang/funcs/simple"
 	"github.com/purpleidea/mgmt/lang/types"
 )

lang/funcs/funcgen/func.go

@@ -101,18 +101,19 @@ func generateTemplate(c config, f functions, path, templateFile, finalName strin
 func (obj *function) MakeGolangArgs() (string, error) {
 	var args []string
 	for i, a := range obj.Args {
-		gol, err := a.ToGolang()
+		input := fmt.Sprintf("input[%d]", i)
+		gol, err := a.ToGolang(input)
 		if err != nil {
 			return "", err
 		}
-		input := fmt.Sprintf("input[%d].%s()", i, gol)
+
 		switch a.Type {
 		case "int":
-			input = fmt.Sprintf("int(%s)", input)
+			gol = fmt.Sprintf("int(%s)", gol)
 		case "[]byte":
-			input = fmt.Sprintf("[]byte(%s)", input)
+			gol = fmt.Sprintf("[]byte(%s)", gol)
 		}
-		args = append(args, input)
+		args = append(args, gol)
 	}
 	for _, a := range obj.ExtraGolangArgs {
 		args = append(args, a.Value)

lang/funcs/funcgen/pkg.go

@@ -33,7 +33,7 @@ import (
 )
 
 var (
-	validSignature = regexp.MustCompile(`^func (?P<name>[A-Z][a-zA-Z0-9]+)\((?P<args>([a-zA-Z]+( (bool|string|int|int64|float64|\[\]byte))?(, )?){0,})\) (?P<return>(bool|string|int|int64|float64|\[\]byte|)|\((bool|string|int|int64|float64|\[\]byte), error\))$`)
+	validSignature = regexp.MustCompile(`^func (?P<name>[A-Z][a-zA-Z0-9]+)\((?P<args>([a-zA-Z]+( (bool|string|int|int64|float64|\[\]byte|\[\]string))?(, )?){0,})\) (?P<return>(bool|string|int|int64|float64|\[\]byte|)|\((bool|string|int|int64|float64|\[\]byte|), error\))$`)
 	errExcluded    = errors.New("function is excluded")
 )
 

lang/funcs/funcgen/templates/generated_funcs.go.tpl

@@ -20,6 +20,7 @@ package core
 import (
 {{ range $i, $func := .Packages }}	{{ if not (eq .Alias "") }}{{.Alias}} {{end}}"{{.Name}}"
 {{ end }}
+	"github.com/purpleidea/mgmt/lang/funcs/funcgen/util"
 	"github.com/purpleidea/mgmt/lang/funcs/simple"
 	"github.com/purpleidea/mgmt/lang/types"
 )

lang/funcs/funcgen/util/util.go

@@ -0,0 +1,33 @@
+// Mgmt
+// Copyright (C) 2013-2023+ James Shubin and the project contributors
+// Written by James Shubin <james@shubin.ca> and the project contributors
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+// Package util provides some functions to be imported by the generated file.
+package util
+
+import (
+	"github.com/purpleidea/mgmt/lang/types"
+)
+
+// MclListToGolang is a helper function that converts an mcl []str to the golang
+// equivalent of []string. This is imported by the generated functions.
+func MclListToGolang(val types.Value) []string {
+	ret := []string{}
+	for _, x := range val.List() {
+		ret = append(ret, x.Str())
+	}
+	return ret
+}