diff options
Diffstat (limited to 'vendor/golang.org/x/text/unicode/norm/transform.go')
-rw-r--r-- | vendor/golang.org/x/text/unicode/norm/transform.go | 88 |
1 files changed, 88 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/unicode/norm/transform.go b/vendor/golang.org/x/text/unicode/norm/transform.go new file mode 100644 index 0000000..a1d366a --- /dev/null +++ b/vendor/golang.org/x/text/unicode/norm/transform.go @@ -0,0 +1,88 @@ +// Copyright 2013 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 norm + +import ( + "unicode/utf8" + + "golang.org/x/text/transform" +) + +// Reset implements the Reset method of the transform.Transformer interface. +func (Form) Reset() {} + +// Transform implements the Transform method of the transform.Transformer +// interface. It may need to write segments of up to MaxSegmentSize at once. +// Users should either catch ErrShortDst and allow dst to grow or have dst be at +// least of size MaxTransformChunkSize to be guaranteed of progress. +func (f Form) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + // Cap the maximum number of src bytes to check. + b := src + eof := atEOF + if ns := len(dst); ns < len(b) { + err = transform.ErrShortDst + eof = false + b = b[:ns] + } + i, ok := formTable[f].quickSpan(inputBytes(b), 0, len(b), eof) + n := copy(dst, b[:i]) + if !ok { + nDst, nSrc, err = f.transform(dst[n:], src[n:], atEOF) + return nDst + n, nSrc + n, err + } + + if err == nil && n < len(src) && !atEOF { + err = transform.ErrShortSrc + } + return n, n, err +} + +func flushTransform(rb *reorderBuffer) bool { + // Write out (must fully fit in dst, or else it is an ErrShortDst). + if len(rb.out) < rb.nrune*utf8.UTFMax { + return false + } + rb.out = rb.out[rb.flushCopy(rb.out):] + return true +} + +var errs = []error{nil, transform.ErrShortDst, transform.ErrShortSrc} + +// transform implements the transform.Transformer interface. It is only called +// when quickSpan does not pass for a given string. +func (f Form) transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { + // TODO: get rid of reorderBuffer. See CL 23460044. + rb := reorderBuffer{} + rb.init(f, src) + for { + // Load segment into reorder buffer. + rb.setFlusher(dst[nDst:], flushTransform) + end := decomposeSegment(&rb, nSrc, atEOF) + if end < 0 { + return nDst, nSrc, errs[-end] + } + nDst = len(dst) - len(rb.out) + nSrc = end + + // Next quickSpan. + end = rb.nsrc + eof := atEOF + if n := nSrc + len(dst) - nDst; n < end { + err = transform.ErrShortDst + end = n + eof = false + } + end, ok := rb.f.quickSpan(rb.src, nSrc, end, eof) + n := copy(dst[nDst:], rb.src.bytes[nSrc:end]) + nSrc += n + nDst += n + if ok { + if err == nil && n < rb.nsrc && !atEOF { + err = transform.ErrShortSrc + } + return nDst, nSrc, err + } + } +} |