mirror of
https://github.com/go-gitea/gitea.git
synced 2024-12-04 14:46:57 -05:00
458 lines
11 KiB
Go
458 lines
11 KiB
Go
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//
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// Blackfriday Markdown Processor
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// Available at http://github.com/russross/blackfriday
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//
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// Copyright © 2011 Russ Ross <russ@russross.com>.
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// Distributed under the Simplified BSD License.
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// See README.md for details.
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//
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//
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//
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// SmartyPants rendering
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//
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//
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package blackfriday
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import (
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"bytes"
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"io"
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)
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// SPRenderer is a struct containing state of a Smartypants renderer.
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type SPRenderer struct {
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inSingleQuote bool
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inDoubleQuote bool
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callbacks [256]smartCallback
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}
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func wordBoundary(c byte) bool {
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return c == 0 || isspace(c) || ispunct(c)
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}
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func tolower(c byte) byte {
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if c >= 'A' && c <= 'Z' {
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return c - 'A' + 'a'
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}
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return c
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}
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func isdigit(c byte) bool {
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return c >= '0' && c <= '9'
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}
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func smartQuoteHelper(out *bytes.Buffer, previousChar byte, nextChar byte, quote byte, isOpen *bool, addNBSP bool) bool {
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// edge of the buffer is likely to be a tag that we don't get to see,
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// so we treat it like text sometimes
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// enumerate all sixteen possibilities for (previousChar, nextChar)
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// each can be one of {0, space, punct, other}
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switch {
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case previousChar == 0 && nextChar == 0:
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// context is not any help here, so toggle
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*isOpen = !*isOpen
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case isspace(previousChar) && nextChar == 0:
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// [ "] might be [ "<code>foo...]
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*isOpen = true
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case ispunct(previousChar) && nextChar == 0:
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// [!"] hmm... could be [Run!"] or [("<code>...]
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*isOpen = false
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case /* isnormal(previousChar) && */ nextChar == 0:
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// [a"] is probably a close
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*isOpen = false
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case previousChar == 0 && isspace(nextChar):
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// [" ] might be [...foo</code>" ]
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*isOpen = false
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case isspace(previousChar) && isspace(nextChar):
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// [ " ] context is not any help here, so toggle
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*isOpen = !*isOpen
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case ispunct(previousChar) && isspace(nextChar):
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// [!" ] is probably a close
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*isOpen = false
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case /* isnormal(previousChar) && */ isspace(nextChar):
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// [a" ] this is one of the easy cases
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*isOpen = false
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case previousChar == 0 && ispunct(nextChar):
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// ["!] hmm... could be ["$1.95] or [</code>"!...]
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*isOpen = false
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case isspace(previousChar) && ispunct(nextChar):
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// [ "!] looks more like [ "$1.95]
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*isOpen = true
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case ispunct(previousChar) && ispunct(nextChar):
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// [!"!] context is not any help here, so toggle
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*isOpen = !*isOpen
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case /* isnormal(previousChar) && */ ispunct(nextChar):
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// [a"!] is probably a close
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*isOpen = false
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case previousChar == 0 /* && isnormal(nextChar) */ :
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// ["a] is probably an open
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*isOpen = true
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case isspace(previousChar) /* && isnormal(nextChar) */ :
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// [ "a] this is one of the easy cases
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*isOpen = true
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case ispunct(previousChar) /* && isnormal(nextChar) */ :
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// [!"a] is probably an open
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*isOpen = true
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default:
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// [a'b] maybe a contraction?
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*isOpen = false
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}
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// Note that with the limited lookahead, this non-breaking
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// space will also be appended to single double quotes.
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if addNBSP && !*isOpen {
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out.WriteString(" ")
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}
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out.WriteByte('&')
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if *isOpen {
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out.WriteByte('l')
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} else {
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out.WriteByte('r')
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}
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out.WriteByte(quote)
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out.WriteString("quo;")
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if addNBSP && *isOpen {
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out.WriteString(" ")
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}
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return true
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}
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func (r *SPRenderer) smartSingleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
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if len(text) >= 2 {
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t1 := tolower(text[1])
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if t1 == '\'' {
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nextChar := byte(0)
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if len(text) >= 3 {
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nextChar = text[2]
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}
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if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) {
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return 1
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}
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}
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if (t1 == 's' || t1 == 't' || t1 == 'm' || t1 == 'd') && (len(text) < 3 || wordBoundary(text[2])) {
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out.WriteString("’")
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return 0
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}
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if len(text) >= 3 {
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t2 := tolower(text[2])
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if ((t1 == 'r' && t2 == 'e') || (t1 == 'l' && t2 == 'l') || (t1 == 'v' && t2 == 'e')) &&
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(len(text) < 4 || wordBoundary(text[3])) {
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out.WriteString("’")
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return 0
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}
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}
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}
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nextChar := byte(0)
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if len(text) > 1 {
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nextChar = text[1]
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}
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if smartQuoteHelper(out, previousChar, nextChar, 's', &r.inSingleQuote, false) {
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return 0
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartParens(out *bytes.Buffer, previousChar byte, text []byte) int {
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if len(text) >= 3 {
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t1 := tolower(text[1])
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t2 := tolower(text[2])
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if t1 == 'c' && t2 == ')' {
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out.WriteString("©")
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return 2
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}
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if t1 == 'r' && t2 == ')' {
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out.WriteString("®")
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return 2
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}
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if len(text) >= 4 && t1 == 't' && t2 == 'm' && text[3] == ')' {
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out.WriteString("™")
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return 3
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}
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartDash(out *bytes.Buffer, previousChar byte, text []byte) int {
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if len(text) >= 2 {
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if text[1] == '-' {
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out.WriteString("—")
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return 1
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}
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if wordBoundary(previousChar) && wordBoundary(text[1]) {
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out.WriteString("–")
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return 0
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}
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartDashLatex(out *bytes.Buffer, previousChar byte, text []byte) int {
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if len(text) >= 3 && text[1] == '-' && text[2] == '-' {
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out.WriteString("—")
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return 2
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}
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if len(text) >= 2 && text[1] == '-' {
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out.WriteString("–")
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return 1
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartAmpVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte, addNBSP bool) int {
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if bytes.HasPrefix(text, []byte(""")) {
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nextChar := byte(0)
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if len(text) >= 7 {
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nextChar = text[6]
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}
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if smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, addNBSP) {
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return 5
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}
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}
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if bytes.HasPrefix(text, []byte("�")) {
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return 3
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}
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out.WriteByte('&')
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return 0
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}
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func (r *SPRenderer) smartAmp(angledQuotes, addNBSP bool) func(*bytes.Buffer, byte, []byte) int {
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var quote byte = 'd'
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if angledQuotes {
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quote = 'a'
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}
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return func(out *bytes.Buffer, previousChar byte, text []byte) int {
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return r.smartAmpVariant(out, previousChar, text, quote, addNBSP)
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}
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}
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func (r *SPRenderer) smartPeriod(out *bytes.Buffer, previousChar byte, text []byte) int {
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if len(text) >= 3 && text[1] == '.' && text[2] == '.' {
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out.WriteString("…")
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return 2
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}
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if len(text) >= 5 && text[1] == ' ' && text[2] == '.' && text[3] == ' ' && text[4] == '.' {
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out.WriteString("…")
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return 4
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartBacktick(out *bytes.Buffer, previousChar byte, text []byte) int {
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if len(text) >= 2 && text[1] == '`' {
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nextChar := byte(0)
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if len(text) >= 3 {
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nextChar = text[2]
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}
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if smartQuoteHelper(out, previousChar, nextChar, 'd', &r.inDoubleQuote, false) {
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return 1
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}
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartNumberGeneric(out *bytes.Buffer, previousChar byte, text []byte) int {
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if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
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// is it of the form digits/digits(word boundary)?, i.e., \d+/\d+\b
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// note: check for regular slash (/) or fraction slash (⁄, 0x2044, or 0xe2 81 84 in utf-8)
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// and avoid changing dates like 1/23/2005 into fractions.
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numEnd := 0
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for len(text) > numEnd && isdigit(text[numEnd]) {
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numEnd++
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}
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if numEnd == 0 {
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out.WriteByte(text[0])
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return 0
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}
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denStart := numEnd + 1
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if len(text) > numEnd+3 && text[numEnd] == 0xe2 && text[numEnd+1] == 0x81 && text[numEnd+2] == 0x84 {
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denStart = numEnd + 3
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} else if len(text) < numEnd+2 || text[numEnd] != '/' {
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out.WriteByte(text[0])
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return 0
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}
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denEnd := denStart
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for len(text) > denEnd && isdigit(text[denEnd]) {
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denEnd++
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}
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if denEnd == denStart {
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out.WriteByte(text[0])
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return 0
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}
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if len(text) == denEnd || wordBoundary(text[denEnd]) && text[denEnd] != '/' {
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out.WriteString("<sup>")
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out.Write(text[:numEnd])
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out.WriteString("</sup>⁄<sub>")
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out.Write(text[denStart:denEnd])
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out.WriteString("</sub>")
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return denEnd - 1
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}
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartNumber(out *bytes.Buffer, previousChar byte, text []byte) int {
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if wordBoundary(previousChar) && previousChar != '/' && len(text) >= 3 {
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if text[0] == '1' && text[1] == '/' && text[2] == '2' {
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if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' {
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out.WriteString("½")
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return 2
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}
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}
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if text[0] == '1' && text[1] == '/' && text[2] == '4' {
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if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 5 && tolower(text[3]) == 't' && tolower(text[4]) == 'h') {
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out.WriteString("¼")
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return 2
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}
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}
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if text[0] == '3' && text[1] == '/' && text[2] == '4' {
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if len(text) < 4 || wordBoundary(text[3]) && text[3] != '/' || (len(text) >= 6 && tolower(text[3]) == 't' && tolower(text[4]) == 'h' && tolower(text[5]) == 's') {
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out.WriteString("¾")
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return 2
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}
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}
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}
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out.WriteByte(text[0])
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return 0
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}
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func (r *SPRenderer) smartDoubleQuoteVariant(out *bytes.Buffer, previousChar byte, text []byte, quote byte) int {
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nextChar := byte(0)
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if len(text) > 1 {
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nextChar = text[1]
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}
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if !smartQuoteHelper(out, previousChar, nextChar, quote, &r.inDoubleQuote, false) {
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out.WriteString(""")
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}
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return 0
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}
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func (r *SPRenderer) smartDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
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return r.smartDoubleQuoteVariant(out, previousChar, text, 'd')
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}
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func (r *SPRenderer) smartAngledDoubleQuote(out *bytes.Buffer, previousChar byte, text []byte) int {
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return r.smartDoubleQuoteVariant(out, previousChar, text, 'a')
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}
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func (r *SPRenderer) smartLeftAngle(out *bytes.Buffer, previousChar byte, text []byte) int {
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i := 0
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for i < len(text) && text[i] != '>' {
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i++
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}
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out.Write(text[:i+1])
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return i
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}
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type smartCallback func(out *bytes.Buffer, previousChar byte, text []byte) int
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// NewSmartypantsRenderer constructs a Smartypants renderer object.
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func NewSmartypantsRenderer(flags HTMLFlags) *SPRenderer {
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var (
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r SPRenderer
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smartAmpAngled = r.smartAmp(true, false)
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smartAmpAngledNBSP = r.smartAmp(true, true)
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smartAmpRegular = r.smartAmp(false, false)
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smartAmpRegularNBSP = r.smartAmp(false, true)
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addNBSP = flags&SmartypantsQuotesNBSP != 0
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)
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if flags&SmartypantsAngledQuotes == 0 {
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r.callbacks['"'] = r.smartDoubleQuote
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if !addNBSP {
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r.callbacks['&'] = smartAmpRegular
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} else {
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r.callbacks['&'] = smartAmpRegularNBSP
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}
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} else {
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r.callbacks['"'] = r.smartAngledDoubleQuote
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if !addNBSP {
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r.callbacks['&'] = smartAmpAngled
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} else {
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r.callbacks['&'] = smartAmpAngledNBSP
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}
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}
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|||
|
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:])
|
|||
|
}
|
|||
|
}
|