Files
mgmt/lang/funcs/structs/const.go
James Shubin 3e31ee9455 legal: Additional permission under GNU GPL version 3 section 7
With the recent merging of embedded package imports and the entry CLI
package, it is now possible for users to build in mcl code into a single
binary. This additional permission makes it explicitly clear that this
is permitted to make it easier for those users. The condition is phrased
so that the terms can be "patched" by the original author if it's
necessary for the project. For example, if the name of the language
(mcl) changes, has a differently named new version, someone finds a
phrasing improvement or a legal loophole, or for some other
reasonable circumstance. Now go write some beautiful embedded tools!
2024-03-05 01:04:09 -05:00

105 lines
3.3 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 <http://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 structs
import (
"context"
"fmt"
"github.com/purpleidea/mgmt/lang/interfaces"
"github.com/purpleidea/mgmt/lang/types"
)
const (
// ConstFuncName is the unique name identifier for this function.
ConstFuncName = "const"
)
// ConstFunc is a function that returns the constant value passed to Value.
type ConstFunc struct {
Value types.Value
NameHint string
init *interfaces.Init
}
// String returns a simple name for this function. This is needed so this struct
// can satisfy the pgraph.Vertex interface.
func (obj *ConstFunc) String() string {
if obj.NameHint != "" {
return obj.NameHint
}
return ConstFuncName
//return fmt.Sprintf("%s: %s(%s)", ConstFuncName, obj.Value.Type().String(), obj.Value.String())
//return fmt.Sprintf("%s(%s)", obj.Value.Type().String(), obj.Value.String())
}
// Validate makes sure we've built our struct properly.
func (obj *ConstFunc) Validate() error {
if obj.Value == nil {
return fmt.Errorf("must specify `Value` input")
}
return nil
}
// Info returns some static info about itself.
func (obj *ConstFunc) Info() *interfaces.Info {
var typ *types.Type
if obj.Value != nil { // don't panic if called speculatively
if t := obj.Value.Type(); t != nil {
typ = types.NewType(fmt.Sprintf("func() %s", t.String()))
}
}
return &interfaces.Info{
Pure: true,
Memo: false, // TODO: ???
Sig: typ,
Err: obj.Validate(), // XXX: implement this and check .Err in engine!
}
}
// Init runs some startup code for this const.
func (obj *ConstFunc) Init(init *interfaces.Init) error {
obj.init = init
return nil
}
// Stream returns the single value that this const has, and then closes.
func (obj *ConstFunc) Stream(ctx context.Context) error {
select {
case obj.init.Output <- obj.Value:
// pass
case <-ctx.Done():
return nil
}
close(obj.init.Output) // signal that we're done sending
return nil
}