Files
mgmt/lang/core/map_lookup_default.go

62 lines
2.3 KiB
Go

// Mgmt
// Copyright (C) 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"
"github.com/purpleidea/mgmt/lang/funcs/simple"
"github.com/purpleidea/mgmt/lang/types"
)
const (
// MapLookupDefaultFuncName is the name this function is registered as.
MapLookupDefaultFuncName = "map_lookup_default"
)
func init() {
simple.Register(MapLookupDefaultFuncName, &simple.Scaffold{
T: types.NewType("func(map map{?1: ?2}, key ?1, default ?2) ?2"),
F: MapLookupDefault,
})
}
// MapLookupDefault returns the value corresponding to the input key in the map.
// If the value is not present, it returns the default value supplied.
func MapLookupDefault(ctx context.Context, input []types.Value) (types.Value, error) {
m := input[0].(*types.MapValue)
val, exists := m.Lookup(input[1])
if !exists {
return input[2], nil // default value
}
return val, nil
}