pulumi/pkg/codegen/nodejs/utilities.go

70 lines
2.0 KiB
Go

// Copyright 2016-2018, Pulumi Corporation.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package nodejs
import (
"io"
"strings"
"unicode"
)
// isLegalIdentifierStart returns true if it is legal for c to be the first character of a JavaScript identifier as per
// ECMA-262.
func isLegalIdentifierStart(c rune) bool {
return c == '$' || c == '_' ||
unicode.In(c, unicode.Lu, unicode.Ll, unicode.Lt, unicode.Lm, unicode.Lo, unicode.Nl)
}
// isLegalIdentifierPart returns true if it is legal for c to be part of a JavaScript identifier (besides the first
// character) as per ECMA-262.
func isLegalIdentifierPart(c rune) bool {
return isLegalIdentifierStart(c) || unicode.In(c, unicode.Mn, unicode.Mc, unicode.Nd, unicode.Pc)
}
// isLegalIdentifier returns true if s is a legal JavaScript identifier as per ECMA-262.
func isLegalIdentifier(s string) bool {
reader := strings.NewReader(s)
c, _, _ := reader.ReadRune()
if !isLegalIdentifierStart(c) {
return false
}
for {
c, _, err := reader.ReadRune()
if err != nil {
return err == io.EOF
}
if !isLegalIdentifierPart(c) {
return false
}
}
}
// cleanName replaces characters that are not allowed in JavaScript identifiers with underscores. No attempt is made to
// ensure that the result is unique.
func cleanName(name string) string {
var builder strings.Builder
for i, c := range name {
if !isLegalIdentifierPart(c) {
builder.WriteRune('_')
} else {
if i == 0 && !isLegalIdentifierStart(c) {
builder.WriteRune('_')
}
builder.WriteRune(c)
}
}
return builder.String()
}