Files
mgmt/lang/core/len.go
James Shubin 018d3efc90 lang: funcs: Move standalone functions into core
Everything should be all together.
2024-11-21 22:56:17 -05:00

98 lines
3.1 KiB
Go

// Mgmt
// Copyright (C) 2013-2024+ 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 <https://www.gnu.org/licenses/>.
//
// Additional permission under GNU GPL version 3 section 7
//
// If you modify this program, or any covered work, by linking or combining it
// with embedded mcl code and modules (and that the embedded mcl code and
// modules which link with this program, contain a copy of their source code in
// the authoritative form) containing parts covered by the terms of any other
// license, the licensors of this program grant you additional permission to
// convey the resulting work. Furthermore, the licensors of this program grant
// the original author, James Shubin, additional permission to update this
// additional permission if he deems it necessary to achieve the goals of this
// additional permission.
package core
import (
"context"
"fmt"
"github.com/purpleidea/mgmt/lang/funcs/simple"
"github.com/purpleidea/mgmt/lang/types"
)
func init() {
simple.Register("len", &simple.Scaffold{
T: types.NewType("func(?1) int"),
// TODO: should we add support for struct or func lengths?
C: simple.TypeMatch([]string{
"func(str) int",
"func([]?1) int",
"func(map{?1: ?2}) int",
}),
//C: func(typ *types.Type) error {
// if typ == nil {
// return fmt.Errorf("nil type")
// }
// if typ.Kind != types.KindFunc {
// return fmt.Errorf("not a func")
// }
// if len(typ.Map) != 1 || len(typ.Ord) != 1 {
// return fmt.Errorf("arg count wrong")
// }
// if err := typ.Out.Cmp(types.TypeInt); err != nil {
// return err
// }
// t := typ.Map[typ.Ord[0]]
// if t.Cmp(types.TypeStr) == nil {
// return nil // func(str) int
// }
// if t.Kind == types.KindList {
// return nil // func([]?1) int
// }
// if t.Kind == types.KindMap {
// return nil // func(map{?1: ?2}) int
// }
// return fmt.Errorf("can't determine length of %s", t)
//},
F: Len,
})
}
// Len returns the number of elements in a list or the number of key pairs in a
// map. It can operate on either of these types.
func Len(ctx context.Context, input []types.Value) (types.Value, error) {
var length int
switch k := input[0].Type().Kind; k {
case types.KindStr:
length = len(input[0].Str())
case types.KindList:
length = len(input[0].List())
case types.KindMap:
length = len(input[0].Map())
default:
return nil, fmt.Errorf("unsupported kind: %+v", k)
}
return &types.IntValue{
V: int64(length),
}, nil
}