diff options
Diffstat (limited to 'vendor/github.com/gomarkdown/markdown/html/smartypants.go')
| -rw-r--r-- | vendor/github.com/gomarkdown/markdown/html/smartypants.go | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/vendor/github.com/gomarkdown/markdown/html/smartypants.go b/vendor/github.com/gomarkdown/markdown/html/smartypants.go new file mode 100644 index 00000000..a09866b0 --- /dev/null +++ b/vendor/github.com/gomarkdown/markdown/html/smartypants.go @@ -0,0 +1,444 @@ +package html + +import ( + "bytes" + "io" +) + +// SmartyPants rendering + +// SPRenderer is a struct containing state of a Smartypants renderer. +type SPRenderer struct { + inSingleQuote bool + inDoubleQuote bool + callbacks [256]smartCallback +} + +func wordBoundary(c byte) bool { + return c == 0 || isSpace(c) || isPunctuation(c) +} + +func tolower(c byte) byte { + if c >= 'A' && c <= 'Z' { + return c - 'A' + 'a' + } + return c +} + +func isdigit(c byte) bool { + return c >= '0' && c <= '9' +} + +func smartQuoteHelper(out *bytes.Buffer, previousChar byte, nextChar byte, quote byte, isOpen *bool, addNBSP bool) bool { + // edge of the buffer is likely to be a tag that we don't get to see, + // so we treat it like text sometimes + + // enumerate all sixteen possibilities for (previousChar, nextChar) + // each can be one of {0, space, punct, other} + switch { + case previousChar == 0 && nextChar == 0: + // context is not any help here, so toggle + *isOpen = !*isOpen + case isSpace(previousChar) && nextChar == 0: + // [ "] might be [ "<code>foo...] + *isOpen = true + case isPunctuation(previousChar) && nextChar == 0: + // [!"] hmm... could be [Run!"] or [("<code>...] + *isOpen = false + case /* isnormal(previousChar) && */ nextChar == 0: + // [a"] is probably a close + *isOpen = false + case previousChar == 0 && isSpace(nextChar): + // [" ] might be [...foo</code>" ] + *isOpen = false + case isSpace(previousChar) && isSpace(nextChar): + // [ " ] context is not any help here, so toggle + *isOpen = !*isOpen + case isPunctuation(previousChar) && isSpace(nextChar): + // [!" ] is probably a close + *isOpen = false + case /* isnormal(previousChar) && */ isSpace(nextChar): + // [a" ] this is one of the easy cases + *isOpen = false + case previousChar == 0 && isPunctuation(nextChar): + // ["!] hmm... could be ["$1.95] or [</code>"!...] + *isOpen = false + case isSpace(previousChar) && isPunctuation(nextChar): + // [ "!] looks more like [ "$1.95] + *isOpen = true + case isPunctuation(previousChar) && isPunctuation(nextChar): + // [!"!] context is not any help here, so toggle + *isOpen = !*isOpen + case /* isnormal(previousChar) && */ isPunctuation(nextChar): + // [a"!] is probably a close + *isOpen = false + case previousChar == 0 /* && isnormal(nextChar) */ : + // ["a] is probably an open + *isOpen = true + case isSpace(previousChar) /* && isnormal(nextChar) */ : + // [ "a] this is one of the easy cases + *isOpen = true + case isPunctuation(previousChar) /* && isnormal(nextChar) */ : + // [!"a] is probably an open + *isOpen = true + default: + // [a'b] maybe a contraction? + *isOpen = false + } + + // Note that with the limited lookahead, this non-breaking + // space will also be appended to single double quotes. + if addNBSP && !*isOpen { + out.WriteString(" ") + } + + out.WriteByte('&') + if *isOpen { + out.WriteByte('l') + } else { + out.WriteByte('r') + } + out.WriteByte(quote) + out.WriteString("quo;") + + if addNBSP && *isOpen { + out.WriteString(" ") + } + + return true +} + +func (r *SPRenderer) smartSingleQuote(out *bytes.Buffer, previousChar byte, text []byte) int { + if len(text) >= 2 { + t1 := tolower(text[1]) + + if t1 == '\'' { + nextChar := byte(0) + if len(text) >= 3 { + nextChar = text[2] + } + if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) { + return 1 + } + } + + if (t1 == 's' || t1 == 't' || t1 == 'm' || t1 == 'd') && (len(text) < 3 || wordBoundary(text[2])) { + out.WriteString("’") + return 0 + } + + if len(text) >= 3 { + t2 := tolower(text[2]) + + if ((t1 == 'r' && t2 == 'e') || (t1 == 'l' && t2 == 'l') || (t1 == 'v' && t2 == 'e')) && + (len(text) < 4 || wordBoundary(text[3])) { + out.WriteString("’") + return 0 + } + } + } + + nextChar := byte(0) + if len(text) > 1 { + nextChar = text[1] + } + if smartQuoteHelper(out, previousChar, nextChar, 's', &r.inSingleQuote, false) { + return 0 + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartParens(out *bytes.Buffer, previousChar byte, text []byte) int { + if len(text) >= 3 { + t1 := tolower(text[1]) + t2 := tolower(text[2]) + + if t1 == 'c' && t2 == ')' { + out.WriteString("©") + return 2 + } + + if t1 == 'r' && t2 == ')' { + out.WriteString("®") + return 2 + } + + if len(text) >= 4 && t1 == 't' && t2 == 'm' && text[3] == ')' { + out.WriteString("™") + return 3 + } + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartDash(out *bytes.Buffer, previousChar byte, text []byte) int { + if len(text) >= 2 { + if text[1] == '-' { + out.WriteString("—") + return 1 + } + + if wordBoundary(previousChar) && wordBoundary(text[1]) { + out.WriteString("–") + return 0 + } + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartDashLatex(out *bytes.Buffer, previousChar byte, text []byte) int { + if len(text) >= 3 && text[1] == '-' && text[2] == '-' { + out.WriteString("—") + return 2 + } + if len(text) >= 2 && text[1] == '-' { + out.WriteString("–") + return 1 + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartAmpVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte, addNBSP bool) int { + if bytes.HasPrefix(text, []byte(""")) { + nextChar := byte(0) + if len(text) >= 7 { + nextChar = text[6] + } + if smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, addNBSP) { + return 5 + } + } + + if bytes.HasPrefix(text, []byte("�")) { + return 3 + } + + out.WriteByte('&') + return 0 +} + +func (r *SPRenderer) smartAmp(angledQuotes, addNBSP bool) func(*bytes.Buffer, byte, []byte) int { + var quote byte = 'd' + if angledQuotes { + quote = 'a' + } + + return func(out *bytes.Buffer, previousChar byte, text []byte) int { + return r.smartAmpVariant(out, previousChar, text, quote, addNBSP) + } +} + +func (r *SPRenderer) smartPeriod(out *bytes.Buffer, previousChar byte, text []byte) int { + if len(text) >= 3 && text[1] == '.' && text[2] == '.' { + out.WriteString("…") + return 2 + } + + if len(text) >= 5 && text[1] == ' ' && text[2] == '.' && text[3] == ' ' && text[4] == '.' { + out.WriteString("…") + return 4 + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartBacktick(out *bytes.Buffer, previousChar byte, text []byte) int { + if len(text) >= 2 && text[1] == '`' { + nextChar := byte(0) + if len(text) >= 3 { + nextChar = text[2] + } + if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) { + return 1 + } + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartNumberGeneric(out *bytes.Buffer, previousChar byte, text []byte) int { + if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 { + // is it of the form digits/digits(word boundary)?, i.e., \d+/\d+\b + // note: check for regular slash (/) or fraction slash (⁄, 0x2044, or 0xe2 81 84 in utf-8) + // and avoid changing dates like 1/23/2005 into fractions. + numEnd := 0 + for len(text) > numEnd && isdigit(text[numEnd]) { + numEnd++ + } + if numEnd == 0 { + out.WriteByte(text[0]) + return 0 + } + denStart := numEnd + 1 + if len(text) > numEnd+3 && text[numEnd] == 0xe2 && text[numEnd+1] == 0x81 && text[numEnd+2] == 0x84 { + denStart = numEnd + 3 + } else if len(text) < numEnd+2 || text[numEnd] != '/' { + out.WriteByte(text[0]) + return 0 + } + denEnd := denStart + for len(text) > denEnd && isdigit(text[denEnd]) { + denEnd++ + } + if denEnd == denStart { + out.WriteByte(text[0]) + return 0 + } + if len(text) == denEnd || wordBoundary(text[denEnd]) && text[denEnd] != '/' { + out.WriteString("<sup>") + out.Write(text[:numEnd]) + out.WriteString("</sup>⁄<sub>") + out.Write(text[denStart:denEnd]) + out.WriteString("</sub>") + return denEnd - 1 + } + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartNumber(out *bytes.Buffer, previousChar byte, text []byte) int { + if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 { + if text[0] == '1' && text[1] == '/' && text[2] == '2' { + if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' { + out.WriteString("½") + return 2 + } + } + + if text[0] == '1' && text[1] == '/' && text[2] == '4' { + if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 5 && tolower(text[3]) == 't' && tolower(text[4]) == 'h') { + out.WriteString("¼") + return 2 + } + } + + if text[0] == '3' && text[1] == '/' && text[2] == '4' { + if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 6 && tolower(text[3]) == 't' && tolower(text[4]) == 'h' && tolower(text[5]) == 's') { + out.WriteString("¾") + return 2 + } + } + } + + out.WriteByte(text[0]) + return 0 +} + +func (r *SPRenderer) smartDoubleQuoteVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte) int { + nextChar := byte(0) + if len(text) > 1 { + nextChar = text[1] + } + if !smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, false) { + out.WriteString(""") + } + + return 0 +} + +func (r *SPRenderer) smartDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int { + return r.smartDoubleQuoteVariant(out, previousChar, text, 'd') +} + +func (r *SPRenderer) smartAngledDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int { + return r.smartDoubleQuoteVariant(out, previousChar, text, 'a') +} + +func (r *SPRenderer) smartLeftAngle(out *bytes.Buffer, previousChar byte, text []byte) int { + i := 0 + + for i < len(text) && text[i] != '>' { + i++ + } + + out.Write(text[:i+1]) + return i +} + +type smartCallback func(out *bytes.Buffer, previousChar byte, text []byte) int + +// NewSmartypantsRenderer constructs a Smartypants renderer object. +func NewSmartypantsRenderer(flags Flags) *SPRenderer { + var ( + r SPRenderer + + smartAmpAngled = r.smartAmp(true, false) + smartAmpAngledNBSP = r.smartAmp(true, true) + smartAmpRegular = r.smartAmp(false, false) + smartAmpRegularNBSP = r.smartAmp(false, true) + + addNBSP = flags&SmartypantsQuotesNBSP != 0 + ) + + if flags&SmartypantsAngledQuotes == 0 { + r.callbacks['"'] = r.smartDoubleQuote + if !addNBSP { + r.callbacks['&'] = smartAmpRegular + } else { + r.callbacks['&'] = smartAmpRegularNBSP + } + } else { + r.callbacks['"'] = r.smartAngledDoubleQuote + if !addNBSP { + r.callbacks['&'] = smartAmpAngled + } else { + r.callbacks['&'] = smartAmpAngledNBSP + } + } + r.callbacks['\''] = r.smartSingleQuote + r.callbacks['('] = r.smartParens + if flags&SmartypantsDashes != 0 { + if flags&SmartypantsLatexDashes == 0 { + r.callbacks['-'] = r.smartDash + } else { + r.callbacks['-'] = r.smartDashLatex + } + } + r.callbacks['.'] = r.smartPeriod + if flags&SmartypantsFractions == 0 { + r.callbacks['1'] = r.smartNumber + r.callbacks['3'] = r.smartNumber + } else { + for ch := '1'; ch <= '9'; ch++ { + r.callbacks[ch] = r.smartNumberGeneric + } + } + r.callbacks['<'] = r.smartLeftAngle + r.callbacks['`'] = r.smartBacktick + return &r +} + +// Process is the entry point of the Smartypants renderer. +func (r *SPRenderer) Process(w io.Writer, text []byte) { + mark := 0 + for i := 0; i < len(text); i++ { + if action := r.callbacks[text[i]]; action != nil { + if i > mark { + w.Write(text[mark:i]) + } + previousChar := byte(0) + if i > 0 { + previousChar = text[i-1] + } + var tmp bytes.Buffer + i += action(&tmp, previousChar, text[i:]) + w.Write(tmp.Bytes()) + mark = i + 1 + } + } + if mark < len(text) { + w.Write(text[mark:]) + } +} |