packer/hcl2template/function/length.go
hashicorp-copywrite[bot] 19055df3ec
[COMPLIANCE] License changes (#12568)
* Updating the license from MPL to Business Source License

Going forward, this project will be licensed under the Business Source License v1.1. Please see our blog post for more details at https://hashi.co/bsl-blog, FAQ at https://hashi.co/license-faq, and details of the license at www.hashicorp.com/bsl.

* Update copyright file headers to BUSL-1.1

---------

Co-authored-by: hashicorp-copywrite[bot] <110428419+hashicorp-copywrite[bot]@users.noreply.github.com>
2023-08-10 15:53:29 -07:00

62 lines
2 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package function
import (
"errors"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/function"
"github.com/zclconf/go-cty/cty/function/stdlib"
)
var LengthFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "value",
Type: cty.DynamicPseudoType,
AllowDynamicType: true,
AllowUnknown: true,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
collTy := args[0].Type()
switch {
case collTy == cty.String || collTy.IsTupleType() || collTy.IsObjectType() || collTy.IsListType() || collTy.IsMapType() || collTy.IsSetType() || collTy == cty.DynamicPseudoType:
return cty.Number, nil
default:
return cty.Number, errors.New("argument must be a string, a collection type, or a structural type")
}
},
Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
coll := args[0]
collTy := args[0].Type()
switch {
case collTy == cty.DynamicPseudoType:
return cty.UnknownVal(cty.Number), nil
case collTy.IsTupleType():
l := len(collTy.TupleElementTypes())
return cty.NumberIntVal(int64(l)), nil
case collTy.IsObjectType():
l := len(collTy.AttributeTypes())
return cty.NumberIntVal(int64(l)), nil
case collTy == cty.String:
// We'll delegate to the cty stdlib strlen function here, because
// it deals with all of the complexities of tokenizing unicode
// grapheme clusters.
return stdlib.Strlen(coll)
case collTy.IsListType() || collTy.IsSetType() || collTy.IsMapType():
return coll.Length(), nil
default:
// Should never happen, because of the checks in our Type func above
return cty.UnknownVal(cty.Number), errors.New("impossible value type for length(...)")
}
},
})
// Length returns the number of elements in the given collection or number of
// Unicode characters in the given string.
func Length(collection cty.Value) (cty.Value, error) {
return LengthFunc.Call([]cty.Value{collection})
}