diff options
Diffstat (limited to 'libgo/go/net/http/internal/ascii/print.go')
-rw-r--r-- | libgo/go/net/http/internal/ascii/print.go | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/libgo/go/net/http/internal/ascii/print.go b/libgo/go/net/http/internal/ascii/print.go new file mode 100644 index 0000000..585e5ba --- /dev/null +++ b/libgo/go/net/http/internal/ascii/print.go @@ -0,0 +1,61 @@ +// Copyright 2021 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ascii + +import ( + "strings" + "unicode" +) + +// EqualFold is strings.EqualFold, ASCII only. It reports whether s and t +// are equal, ASCII-case-insensitively. +func EqualFold(s, t string) bool { + if len(s) != len(t) { + return false + } + for i := 0; i < len(s); i++ { + if lower(s[i]) != lower(t[i]) { + return false + } + } + return true +} + +// lower returns the ASCII lowercase version of b. +func lower(b byte) byte { + if 'A' <= b && b <= 'Z' { + return b + ('a' - 'A') + } + return b +} + +// IsPrint returns whether s is ASCII and printable according to +// https://tools.ietf.org/html/rfc20#section-4.2. +func IsPrint(s string) bool { + for i := 0; i < len(s); i++ { + if s[i] < ' ' || s[i] > '~' { + return false + } + } + return true +} + +// Is returns whether s is ASCII. +func Is(s string) bool { + for i := 0; i < len(s); i++ { + if s[i] > unicode.MaxASCII { + return false + } + } + return true +} + +// ToLower returns the lowercase version of s if s is ASCII and printable. +func ToLower(s string) (lower string, ok bool) { + if !IsPrint(s) { + return "", false + } + return strings.ToLower(s), true +} |