summaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/text/secure/precis/nickname.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/text/secure/precis/nickname.go')
-rw-r--r--vendor/golang.org/x/text/secure/precis/nickname.go72
1 files changed, 72 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/secure/precis/nickname.go b/vendor/golang.org/x/text/secure/precis/nickname.go
new file mode 100644
index 0000000..11e0ccb
--- /dev/null
+++ b/vendor/golang.org/x/text/secure/precis/nickname.go
@@ -0,0 +1,72 @@
+// Copyright 2015 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 precis
+
+import (
+ "unicode"
+ "unicode/utf8"
+
+ "golang.org/x/text/transform"
+)
+
+type nickAdditionalMapping struct {
+ // TODO: This transformer needs to be stateless somehow…
+ notStart bool
+ prevSpace bool
+}
+
+func (t *nickAdditionalMapping) Reset() {
+ t.prevSpace = false
+ t.notStart = false
+}
+
+func (t *nickAdditionalMapping) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ // RFC 8266 §2.1. Rules
+ //
+ // 2. Additional Mapping Rule: The additional mapping rule consists of
+ // the following sub-rules.
+ //
+ // a. Map any instances of non-ASCII space to SPACE (U+0020); a
+ // non-ASCII space is any Unicode code point having a general
+ // category of "Zs", naturally with the exception of SPACE
+ // (U+0020). (The inclusion of only ASCII space prevents
+ // confusion with various non-ASCII space code points, many of
+ // which are difficult to reproduce across different input
+ // methods.)
+ //
+ // b. Remove any instances of the ASCII space character at the
+ // beginning or end of a nickname (e.g., "stpeter " is mapped to
+ // "stpeter").
+ //
+ // c. Map interior sequences of more than one ASCII space character
+ // to a single ASCII space character (e.g., "St Peter" is
+ // mapped to "St Peter").
+ for nSrc < len(src) {
+ r, size := utf8.DecodeRune(src[nSrc:])
+ if size == 0 { // Incomplete UTF-8 encoding
+ if !atEOF {
+ return nDst, nSrc, transform.ErrShortSrc
+ }
+ size = 1
+ }
+ if unicode.Is(unicode.Zs, r) {
+ t.prevSpace = true
+ } else {
+ if t.prevSpace && t.notStart {
+ dst[nDst] = ' '
+ nDst += 1
+ }
+ if size != copy(dst[nDst:], src[nSrc:nSrc+size]) {
+ nDst += size
+ return nDst, nSrc, transform.ErrShortDst
+ }
+ nDst += size
+ t.prevSpace = false
+ t.notStart = true
+ }
+ nSrc += size
+ }
+ return nDst, nSrc, nil
+}