--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/golang.org/x/text/runes/cond.go Tue Aug 23 22:39:43 2022 +0200
@@ -0,0 +1,187 @@
+// 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 runes
+
+import (
+ "unicode/utf8"
+
+ "golang.org/x/text/transform"
+)
+
+// Note: below we pass invalid UTF-8 to the tIn and tNotIn transformers as is.
+// This is done for various reasons:
+// - To retain the semantics of the Nop transformer: if input is passed to a Nop
+// one would expect it to be unchanged.
+// - It would be very expensive to pass a converted RuneError to a transformer:
+// a transformer might need more source bytes after RuneError, meaning that
+// the only way to pass it safely is to create a new buffer and manage the
+// intermingling of RuneErrors and normal input.
+// - Many transformers leave ill-formed UTF-8 as is, so this is not
+// inconsistent. Generally ill-formed UTF-8 is only replaced if it is a
+// logical consequence of the operation (as for Map) or if it otherwise would
+// pose security concerns (as for Remove).
+// - An alternative would be to return an error on ill-formed UTF-8, but this
+// would be inconsistent with other operations.
+
+// If returns a transformer that applies tIn to consecutive runes for which
+// s.Contains(r) and tNotIn to consecutive runes for which !s.Contains(r). Reset
+// is called on tIn and tNotIn at the start of each run. A Nop transformer will
+// substitute a nil value passed to tIn or tNotIn. Invalid UTF-8 is translated
+// to RuneError to determine which transformer to apply, but is passed as is to
+// the respective transformer.
+func If(s Set, tIn, tNotIn transform.Transformer) Transformer {
+ if tIn == nil && tNotIn == nil {
+ return Transformer{transform.Nop}
+ }
+ if tIn == nil {
+ tIn = transform.Nop
+ }
+ if tNotIn == nil {
+ tNotIn = transform.Nop
+ }
+ sIn, ok := tIn.(transform.SpanningTransformer)
+ if !ok {
+ sIn = dummySpan{tIn}
+ }
+ sNotIn, ok := tNotIn.(transform.SpanningTransformer)
+ if !ok {
+ sNotIn = dummySpan{tNotIn}
+ }
+
+ a := &cond{
+ tIn: sIn,
+ tNotIn: sNotIn,
+ f: s.Contains,
+ }
+ a.Reset()
+ return Transformer{a}
+}
+
+type dummySpan struct{ transform.Transformer }
+
+func (d dummySpan) Span(src []byte, atEOF bool) (n int, err error) {
+ return 0, transform.ErrEndOfSpan
+}
+
+type cond struct {
+ tIn, tNotIn transform.SpanningTransformer
+ f func(rune) bool
+ check func(rune) bool // current check to perform
+ t transform.SpanningTransformer // current transformer to use
+}
+
+// Reset implements transform.Transformer.
+func (t *cond) Reset() {
+ t.check = t.is
+ t.t = t.tIn
+ t.t.Reset() // notIn will be reset on first usage.
+}
+
+func (t *cond) is(r rune) bool {
+ if t.f(r) {
+ return true
+ }
+ t.check = t.isNot
+ t.t = t.tNotIn
+ t.tNotIn.Reset()
+ return false
+}
+
+func (t *cond) isNot(r rune) bool {
+ if !t.f(r) {
+ return true
+ }
+ t.check = t.is
+ t.t = t.tIn
+ t.tIn.Reset()
+ return false
+}
+
+// This implementation of Span doesn't help all too much, but it needs to be
+// there to satisfy this package's Transformer interface.
+// TODO: there are certainly room for improvements, though. For example, if
+// t.t == transform.Nop (which will a common occurrence) it will save a bundle
+// to special-case that loop.
+func (t *cond) Span(src []byte, atEOF bool) (n int, err error) {
+ p := 0
+ for n < len(src) && err == nil {
+ // Don't process too much at a time as the Spanner that will be
+ // called on this block may terminate early.
+ const maxChunk = 4096
+ max := len(src)
+ if v := n + maxChunk; v < max {
+ max = v
+ }
+ atEnd := false
+ size := 0
+ current := t.t
+ for ; p < max; p += size {
+ r := rune(src[p])
+ if r < utf8.RuneSelf {
+ size = 1
+ } else if r, size = utf8.DecodeRune(src[p:]); size == 1 {
+ if !atEOF && !utf8.FullRune(src[p:]) {
+ err = transform.ErrShortSrc
+ break
+ }
+ }
+ if !t.check(r) {
+ // The next rune will be the start of a new run.
+ atEnd = true
+ break
+ }
+ }
+ n2, err2 := current.Span(src[n:p], atEnd || (atEOF && p == len(src)))
+ n += n2
+ if err2 != nil {
+ return n, err2
+ }
+ // At this point either err != nil or t.check will pass for the rune at p.
+ p = n + size
+ }
+ return n, err
+}
+
+func (t *cond) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) {
+ p := 0
+ for nSrc < len(src) && err == nil {
+ // Don't process too much at a time, as the work might be wasted if the
+ // destination buffer isn't large enough to hold the result or a
+ // transform returns an error early.
+ const maxChunk = 4096
+ max := len(src)
+ if n := nSrc + maxChunk; n < len(src) {
+ max = n
+ }
+ atEnd := false
+ size := 0
+ current := t.t
+ for ; p < max; p += size {
+ r := rune(src[p])
+ if r < utf8.RuneSelf {
+ size = 1
+ } else if r, size = utf8.DecodeRune(src[p:]); size == 1 {
+ if !atEOF && !utf8.FullRune(src[p:]) {
+ err = transform.ErrShortSrc
+ break
+ }
+ }
+ if !t.check(r) {
+ // The next rune will be the start of a new run.
+ atEnd = true
+ break
+ }
+ }
+ nDst2, nSrc2, err2 := current.Transform(dst[nDst:], src[nSrc:p], atEnd || (atEOF && p == len(src)))
+ nDst += nDst2
+ nSrc += nSrc2
+ if err2 != nil {
+ return nDst, nSrc, err2
+ }
+ // At this point either err != nil or t.check will pass for the rune at p.
+ p = nSrc + size
+ }
+ return nDst, nSrc, err
+}