From 8c12c6939aab9106db14ec2d11d983bc5b29fb2c Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sun, 7 Jul 2019 21:33:44 +0100 Subject: Switch to modules --- vendor/golang.org/x/text/transform/transform.go | 705 ------------------------ 1 file changed, 705 deletions(-) delete mode 100644 vendor/golang.org/x/text/transform/transform.go (limited to 'vendor/golang.org/x/text/transform/transform.go') diff --git a/vendor/golang.org/x/text/transform/transform.go b/vendor/golang.org/x/text/transform/transform.go deleted file mode 100644 index fe47b9b..0000000 --- a/vendor/golang.org/x/text/transform/transform.go +++ /dev/null @@ -1,705 +0,0 @@ -// 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 transform provides reader and writer wrappers that transform the -// bytes passing through as well as various transformations. Example -// transformations provided by other packages include normalization and -// conversion between character sets. -package transform // import "golang.org/x/text/transform" - -import ( - "bytes" - "errors" - "io" - "unicode/utf8" -) - -var ( - // ErrShortDst means that the destination buffer was too short to - // receive all of the transformed bytes. - ErrShortDst = errors.New("transform: short destination buffer") - - // ErrShortSrc means that the source buffer has insufficient data to - // complete the transformation. - ErrShortSrc = errors.New("transform: short source buffer") - - // ErrEndOfSpan means that the input and output (the transformed input) - // are not identical. - ErrEndOfSpan = errors.New("transform: input and output are not identical") - - // errInconsistentByteCount means that Transform returned success (nil - // error) but also returned nSrc inconsistent with the src argument. - errInconsistentByteCount = errors.New("transform: inconsistent byte count returned") - - // errShortInternal means that an internal buffer is not large enough - // to make progress and the Transform operation must be aborted. - errShortInternal = errors.New("transform: short internal buffer") -) - -// Transformer transforms bytes. -type Transformer interface { - // Transform writes to dst the transformed bytes read from src, and - // returns the number of dst bytes written and src bytes read. The - // atEOF argument tells whether src represents the last bytes of the - // input. - // - // Callers should always process the nDst bytes produced and account - // for the nSrc bytes consumed before considering the error err. - // - // A nil error means that all of the transformed bytes (whether freshly - // transformed from src or left over from previous Transform calls) - // were written to dst. A nil error can be returned regardless of - // whether atEOF is true. If err is nil then nSrc must equal len(src); - // the converse is not necessarily true. - // - // ErrShortDst means that dst was too short to receive all of the - // transformed bytes. ErrShortSrc means that src had insufficient data - // to complete the transformation. If both conditions apply, then - // either error may be returned. Other than the error conditions listed - // here, implementations are free to report other errors that arise. - Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) - - // Reset resets the state and allows a Transformer to be reused. - Reset() -} - -// SpanningTransformer extends the Transformer interface with a Span method -// that determines how much of the input already conforms to the Transformer. -type SpanningTransformer interface { - Transformer - - // Span returns a position in src such that transforming src[:n] results in - // identical output src[:n] for these bytes. It does not necessarily return - // the largest such n. The atEOF argument tells whether src represents the - // last bytes of the input. - // - // Callers should always account for the n bytes consumed before - // considering the error err. - // - // A nil error means that all input bytes are known to be identical to the - // output produced by the Transformer. A nil error can be be returned - // regardless of whether atEOF is true. If err is nil, then then n must - // equal len(src); the converse is not necessarily true. - // - // ErrEndOfSpan means that the Transformer output may differ from the - // input after n bytes. Note that n may be len(src), meaning that the output - // would contain additional bytes after otherwise identical output. - // ErrShortSrc means that src had insufficient data to determine whether the - // remaining bytes would change. Other than the error conditions listed - // here, implementations are free to report other errors that arise. - // - // Calling Span can modify the Transformer state as a side effect. In - // effect, it does the transformation just as calling Transform would, only - // without copying to a destination buffer and only up to a point it can - // determine the input and output bytes are the same. This is obviously more - // limited than calling Transform, but can be more efficient in terms of - // copying and allocating buffers. Calls to Span and Transform may be - // interleaved. - Span(src []byte, atEOF bool) (n int, err error) -} - -// NopResetter can be embedded by implementations of Transformer to add a nop -// Reset method. -type NopResetter struct{} - -// Reset implements the Reset method of the Transformer interface. -func (NopResetter) Reset() {} - -// Reader wraps another io.Reader by transforming the bytes read. -type Reader struct { - r io.Reader - t Transformer - err error - - // dst[dst0:dst1] contains bytes that have been transformed by t but - // not yet copied out via Read. - dst []byte - dst0, dst1 int - - // src[src0:src1] contains bytes that have been read from r but not - // yet transformed through t. - src []byte - src0, src1 int - - // transformComplete is whether the transformation is complete, - // regardless of whether or not it was successful. - transformComplete bool -} - -const defaultBufSize = 4096 - -// NewReader returns a new Reader that wraps r by transforming the bytes read -// via t. It calls Reset on t. -func NewReader(r io.Reader, t Transformer) *Reader { - t.Reset() - return &Reader{ - r: r, - t: t, - dst: make([]byte, defaultBufSize), - src: make([]byte, defaultBufSize), - } -} - -// Read implements the io.Reader interface. -func (r *Reader) Read(p []byte) (int, error) { - n, err := 0, error(nil) - for { - // Copy out any transformed bytes and return the final error if we are done. - if r.dst0 != r.dst1 { - n = copy(p, r.dst[r.dst0:r.dst1]) - r.dst0 += n - if r.dst0 == r.dst1 && r.transformComplete { - return n, r.err - } - return n, nil - } else if r.transformComplete { - return 0, r.err - } - - // Try to transform some source bytes, or to flush the transformer if we - // are out of source bytes. We do this even if r.r.Read returned an error. - // As the io.Reader documentation says, "process the n > 0 bytes returned - // before considering the error". - if r.src0 != r.src1 || r.err != nil { - r.dst0 = 0 - r.dst1, n, err = r.t.Transform(r.dst, r.src[r.src0:r.src1], r.err == io.EOF) - r.src0 += n - - switch { - case err == nil: - if r.src0 != r.src1 { - r.err = errInconsistentByteCount - } - // The Transform call was successful; we are complete if we - // cannot read more bytes into src. - r.transformComplete = r.err != nil - continue - case err == ErrShortDst && (r.dst1 != 0 || n != 0): - // Make room in dst by copying out, and try again. - continue - case err == ErrShortSrc && r.src1-r.src0 != len(r.src) && r.err == nil: - // Read more bytes into src via the code below, and try again. - default: - r.transformComplete = true - // The reader error (r.err) takes precedence over the - // transformer error (err) unless r.err is nil or io.EOF. - if r.err == nil || r.err == io.EOF { - r.err = err - } - continue - } - } - - // Move any untransformed source bytes to the start of the buffer - // and read more bytes. - if r.src0 != 0 { - r.src0, r.src1 = 0, copy(r.src, r.src[r.src0:r.src1]) - } - n, r.err = r.r.Read(r.src[r.src1:]) - r.src1 += n - } -} - -// TODO: implement ReadByte (and ReadRune??). - -// Writer wraps another io.Writer by transforming the bytes read. -// The user needs to call Close to flush unwritten bytes that may -// be buffered. -type Writer struct { - w io.Writer - t Transformer - dst []byte - - // src[:n] contains bytes that have not yet passed through t. - src []byte - n int -} - -// NewWriter returns a new Writer that wraps w by transforming the bytes written -// via t. It calls Reset on t. -func NewWriter(w io.Writer, t Transformer) *Writer { - t.Reset() - return &Writer{ - w: w, - t: t, - dst: make([]byte, defaultBufSize), - src: make([]byte, defaultBufSize), - } -} - -// Write implements the io.Writer interface. If there are not enough -// bytes available to complete a Transform, the bytes will be buffered -// for the next write. Call Close to convert the remaining bytes. -func (w *Writer) Write(data []byte) (n int, err error) { - src := data - if w.n > 0 { - // Append bytes from data to the last remainder. - // TODO: limit the amount copied on first try. - n = copy(w.src[w.n:], data) - w.n += n - src = w.src[:w.n] - } - for { - nDst, nSrc, err := w.t.Transform(w.dst, src, false) - if _, werr := w.w.Write(w.dst[:nDst]); werr != nil { - return n, werr - } - src = src[nSrc:] - if w.n == 0 { - n += nSrc - } else if len(src) <= n { - // Enough bytes from w.src have been consumed. We make src point - // to data instead to reduce the copying. - w.n = 0 - n -= len(src) - src = data[n:] - if n < len(data) && (err == nil || err == ErrShortSrc) { - continue - } - } - switch err { - case ErrShortDst: - // This error is okay as long as we are making progress. - if nDst > 0 || nSrc > 0 { - continue - } - case ErrShortSrc: - if len(src) < len(w.src) { - m := copy(w.src, src) - // If w.n > 0, bytes from data were already copied to w.src and n - // was already set to the number of bytes consumed. - if w.n == 0 { - n += m - } - w.n = m - err = nil - } else if nDst > 0 || nSrc > 0 { - // Not enough buffer to store the remainder. Keep processing as - // long as there is progress. Without this case, transforms that - // require a lookahead larger than the buffer may result in an - // error. This is not something one may expect to be common in - // practice, but it may occur when buffers are set to small - // sizes during testing. - continue - } - case nil: - if w.n > 0 { - err = errInconsistentByteCount - } - } - return n, err - } -} - -// Close implements the io.Closer interface. -func (w *Writer) Close() error { - src := w.src[:w.n] - for { - nDst, nSrc, err := w.t.Transform(w.dst, src, true) - if _, werr := w.w.Write(w.dst[:nDst]); werr != nil { - return werr - } - if err != ErrShortDst { - return err - } - src = src[nSrc:] - } -} - -type nop struct{ NopResetter } - -func (nop) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { - n := copy(dst, src) - if n < len(src) { - err = ErrShortDst - } - return n, n, err -} - -func (nop) Span(src []byte, atEOF bool) (n int, err error) { - return len(src), nil -} - -type discard struct{ NopResetter } - -func (discard) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { - return 0, len(src), nil -} - -var ( - // Discard is a Transformer for which all Transform calls succeed - // by consuming all bytes and writing nothing. - Discard Transformer = discard{} - - // Nop is a SpanningTransformer that copies src to dst. - Nop SpanningTransformer = nop{} -) - -// chain is a sequence of links. A chain with N Transformers has N+1 links and -// N+1 buffers. Of those N+1 buffers, the first and last are the src and dst -// buffers given to chain.Transform and the middle N-1 buffers are intermediate -// buffers owned by the chain. The i'th link transforms bytes from the i'th -// buffer chain.link[i].b at read offset chain.link[i].p to the i+1'th buffer -// chain.link[i+1].b at write offset chain.link[i+1].n, for i in [0, N). -type chain struct { - link []link - err error - // errStart is the index at which the error occurred plus 1. Processing - // errStart at this level at the next call to Transform. As long as - // errStart > 0, chain will not consume any more source bytes. - errStart int -} - -func (c *chain) fatalError(errIndex int, err error) { - if i := errIndex + 1; i > c.errStart { - c.errStart = i - c.err = err - } -} - -type link struct { - t Transformer - // b[p:n] holds the bytes to be transformed by t. - b []byte - p int - n int -} - -func (l *link) src() []byte { - return l.b[l.p:l.n] -} - -func (l *link) dst() []byte { - return l.b[l.n:] -} - -// Chain returns a Transformer that applies t in sequence. -func Chain(t ...Transformer) Transformer { - if len(t) == 0 { - return nop{} - } - c := &chain{link: make([]link, len(t)+1)} - for i, tt := range t { - c.link[i].t = tt - } - // Allocate intermediate buffers. - b := make([][defaultBufSize]byte, len(t)-1) - for i := range b { - c.link[i+1].b = b[i][:] - } - return c -} - -// Reset resets the state of Chain. It calls Reset on all the Transformers. -func (c *chain) Reset() { - for i, l := range c.link { - if l.t != nil { - l.t.Reset() - } - c.link[i].p, c.link[i].n = 0, 0 - } -} - -// TODO: make chain use Span (is going to be fun to implement!) - -// Transform applies the transformers of c in sequence. -func (c *chain) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { - // Set up src and dst in the chain. - srcL := &c.link[0] - dstL := &c.link[len(c.link)-1] - srcL.b, srcL.p, srcL.n = src, 0, len(src) - dstL.b, dstL.n = dst, 0 - var lastFull, needProgress bool // for detecting progress - - // i is the index of the next Transformer to apply, for i in [low, high]. - // low is the lowest index for which c.link[low] may still produce bytes. - // high is the highest index for which c.link[high] has a Transformer. - // The error returned by Transform determines whether to increase or - // decrease i. We try to completely fill a buffer before converting it. - for low, i, high := c.errStart, c.errStart, len(c.link)-2; low <= i && i <= high; { - in, out := &c.link[i], &c.link[i+1] - nDst, nSrc, err0 := in.t.Transform(out.dst(), in.src(), atEOF && low == i) - out.n += nDst - in.p += nSrc - if i > 0 && in.p == in.n { - in.p, in.n = 0, 0 - } - needProgress, lastFull = lastFull, false - switch err0 { - case ErrShortDst: - // Process the destination buffer next. Return if we are already - // at the high index. - if i == high { - return dstL.n, srcL.p, ErrShortDst - } - if out.n != 0 { - i++ - // If the Transformer at the next index is not able to process any - // source bytes there is nothing that can be done to make progress - // and the bytes will remain unprocessed. lastFull is used to - // detect this and break out of the loop with a fatal error. - lastFull = true - continue - } - // The destination buffer was too small, but is completely empty. - // Return a fatal error as this transformation can never complete. - c.fatalError(i, errShortInternal) - case ErrShortSrc: - if i == 0 { - // Save ErrShortSrc in err. All other errors take precedence. - err = ErrShortSrc - break - } - // Source bytes were depleted before filling up the destination buffer. - // Verify we made some progress, move the remaining bytes to the errStart - // and try to get more source bytes. - if needProgress && nSrc == 0 || in.n-in.p == len(in.b) { - // There were not enough source bytes to proceed while the source - // buffer cannot hold any more bytes. Return a fatal error as this - // transformation can never complete. - c.fatalError(i, errShortInternal) - break - } - // in.b is an internal buffer and we can make progress. - in.p, in.n = 0, copy(in.b, in.src()) - fallthrough - case nil: - // if i == low, we have depleted the bytes at index i or any lower levels. - // In that case we increase low and i. In all other cases we decrease i to - // fetch more bytes before proceeding to the next index. - if i > low { - i-- - continue - } - default: - c.fatalError(i, err0) - } - // Exhausted level low or fatal error: increase low and continue - // to process the bytes accepted so far. - i++ - low = i - } - - // If c.errStart > 0, this means we found a fatal error. We will clear - // all upstream buffers. At this point, no more progress can be made - // downstream, as Transform would have bailed while handling ErrShortDst. - if c.errStart > 0 { - for i := 1; i < c.errStart; i++ { - c.link[i].p, c.link[i].n = 0, 0 - } - err, c.errStart, c.err = c.err, 0, nil - } - return dstL.n, srcL.p, err -} - -// Deprecated: use runes.Remove instead. -func RemoveFunc(f func(r rune) bool) Transformer { - return removeF(f) -} - -type removeF func(r rune) bool - -func (removeF) Reset() {} - -// Transform implements the Transformer interface. -func (t removeF) Transform(dst, src []byte, atEOF bool) (nDst, nSrc int, err error) { - for r, sz := rune(0), 0; len(src) > 0; src = src[sz:] { - - if r = rune(src[0]); r < utf8.RuneSelf { - sz = 1 - } else { - r, sz = utf8.DecodeRune(src) - - if sz == 1 { - // Invalid rune. - if !atEOF && !utf8.FullRune(src) { - err = ErrShortSrc - break - } - // We replace illegal bytes with RuneError. Not doing so might - // otherwise turn a sequence of invalid UTF-8 into valid UTF-8. - // The resulting byte sequence may subsequently contain runes - // for which t(r) is true that were passed unnoticed. - if !t(r) { - if nDst+3 > len(dst) { - err = ErrShortDst - break - } - nDst += copy(dst[nDst:], "\uFFFD") - } - nSrc++ - continue - } - } - - if !t(r) { - if nDst+sz > len(dst) { - err = ErrShortDst - break - } - nDst += copy(dst[nDst:], src[:sz]) - } - nSrc += sz - } - return -} - -// grow returns a new []byte that is longer than b, and copies the first n bytes -// of b to the start of the new slice. -func grow(b []byte, n int) []byte { - m := len(b) - if m <= 32 { - m = 64 - } else if m <= 256 { - m *= 2 - } else { - m += m >> 1 - } - buf := make([]byte, m) - copy(buf, b[:n]) - return buf -} - -const initialBufSize = 128 - -// String returns a string with the result of converting s[:n] using t, where -// n <= len(s). If err == nil, n will be len(s). It calls Reset on t. -func String(t Transformer, s string) (result string, n int, err error) { - t.Reset() - if s == "" { - // Fast path for the common case for empty input. Results in about a - // 86% reduction of running time for BenchmarkStringLowerEmpty. - if _, _, err := t.Transform(nil, nil, true); err == nil { - return "", 0, nil - } - } - - // Allocate only once. Note that both dst and src escape when passed to - // Transform. - buf := [2 * initialBufSize]byte{} - dst := buf[:initialBufSize:initialBufSize] - src := buf[initialBufSize : 2*initialBufSize] - - // The input string s is transformed in multiple chunks (starting with a - // chunk size of initialBufSize). nDst and nSrc are per-chunk (or - // per-Transform-call) indexes, pDst and pSrc are overall indexes. - nDst, nSrc := 0, 0 - pDst, pSrc := 0, 0 - - // pPrefix is the length of a common prefix: the first pPrefix bytes of the - // result will equal the first pPrefix bytes of s. It is not guaranteed to - // be the largest such value, but if pPrefix, len(result) and len(s) are - // all equal after the final transform (i.e. calling Transform with atEOF - // being true returned nil error) then we don't need to allocate a new - // result string. - pPrefix := 0 - for { - // Invariant: pDst == pPrefix && pSrc == pPrefix. - - n := copy(src, s[pSrc:]) - nDst, nSrc, err = t.Transform(dst, src[:n], pSrc+n == len(s)) - pDst += nDst - pSrc += nSrc - - // TODO: let transformers implement an optional Spanner interface, akin - // to norm's QuickSpan. This would even allow us to avoid any allocation. - if !bytes.Equal(dst[:nDst], src[:nSrc]) { - break - } - pPrefix = pSrc - if err == ErrShortDst { - // A buffer can only be short if a transformer modifies its input. - break - } else if err == ErrShortSrc { - if nSrc == 0 { - // No progress was made. - break - } - // Equal so far and !atEOF, so continue checking. - } else if err != nil || pPrefix == len(s) { - return string(s[:pPrefix]), pPrefix, err - } - } - // Post-condition: pDst == pPrefix + nDst && pSrc == pPrefix + nSrc. - - // We have transformed the first pSrc bytes of the input s to become pDst - // transformed bytes. Those transformed bytes are discontiguous: the first - // pPrefix of them equal s[:pPrefix] and the last nDst of them equal - // dst[:nDst]. We copy them around, into a new dst buffer if necessary, so - // that they become one contiguous slice: dst[:pDst]. - if pPrefix != 0 { - newDst := dst - if pDst > len(newDst) { - newDst = make([]byte, len(s)+nDst-nSrc) - } - copy(newDst[pPrefix:pDst], dst[:nDst]) - copy(newDst[:pPrefix], s[:pPrefix]) - dst = newDst - } - - // Prevent duplicate Transform calls with atEOF being true at the end of - // the input. Also return if we have an unrecoverable error. - if (err == nil && pSrc == len(s)) || - (err != nil && err != ErrShortDst && err != ErrShortSrc) { - return string(dst[:pDst]), pSrc, err - } - - // Transform the remaining input, growing dst and src buffers as necessary. - for { - n := copy(src, s[pSrc:]) - nDst, nSrc, err := t.Transform(dst[pDst:], src[:n], pSrc+n == len(s)) - pDst += nDst - pSrc += nSrc - - // If we got ErrShortDst or ErrShortSrc, do not grow as long as we can - // make progress. This may avoid excessive allocations. - if err == ErrShortDst { - if nDst == 0 { - dst = grow(dst, pDst) - } - } else if err == ErrShortSrc { - if nSrc == 0 { - src = grow(src, 0) - } - } else if err != nil || pSrc == len(s) { - return string(dst[:pDst]), pSrc, err - } - } -} - -// Bytes returns a new byte slice with the result of converting b[:n] using t, -// where n <= len(b). If err == nil, n will be len(b). It calls Reset on t. -func Bytes(t Transformer, b []byte) (result []byte, n int, err error) { - return doAppend(t, 0, make([]byte, len(b)), b) -} - -// Append appends the result of converting src[:n] using t to dst, where -// n <= len(src), If err == nil, n will be len(src). It calls Reset on t. -func Append(t Transformer, dst, src []byte) (result []byte, n int, err error) { - if len(dst) == cap(dst) { - n := len(src) + len(dst) // It is okay for this to be 0. - b := make([]byte, n) - dst = b[:copy(b, dst)] - } - return doAppend(t, len(dst), dst[:cap(dst)], src) -} - -func doAppend(t Transformer, pDst int, dst, src []byte) (result []byte, n int, err error) { - t.Reset() - pSrc := 0 - for { - nDst, nSrc, err := t.Transform(dst[pDst:], src[pSrc:], true) - pDst += nDst - pSrc += nSrc - if err != ErrShortDst { - return dst[:pDst], pSrc, err - } - - // Grow the destination buffer, but do not grow as long as we can make - // progress. This may avoid excessive allocations. - if nDst == 0 { - dst = grow(dst, pDst) - } - } -} -- cgit v1.2.3