mirror of
https://github.com/russross/blackfriday.git
synced 2024-03-22 13:40:34 +08:00
2126 lines
43 KiB
Go
2126 lines
43 KiB
Go
package main
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import (
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"bytes"
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"fmt"
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"html"
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"sort"
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"unicode"
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)
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const (
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MKDA_NOT_AUTOLINK = iota
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MKDA_NORMAL
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MKDA_EMAIL
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)
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const (
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MKDEXT_NO_INTRA_EMPHASIS = 1 << iota
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MKDEXT_TABLES
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MKDEXT_FENCED_CODE
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MKDEXT_AUTOLINK
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MKDEXT_STRIKETHROUGH
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MKDEXT_LAX_HTML_BLOCKS
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MKDEXT_SPACE_HEADERS
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)
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const (
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_ = iota
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MKD_LIST_ORDERED
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MKD_LI_BLOCK // <li> containing block data
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MKD_LI_END = 8
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)
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const (
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MKD_TABLE_ALIGN_L = 1 << iota
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MKD_TABLE_ALIGN_R
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MKD_TABLE_ALIGN_CENTER = (MKD_TABLE_ALIGN_L | MKD_TABLE_ALIGN_R)
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)
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var block_tags = map[string]int{
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"p": 1, // 0
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"dl": 2,
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"h1": 2,
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"h2": 2,
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"h3": 2,
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"h4": 2,
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"h5": 2,
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"h6": 2,
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"ol": 2,
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"ul": 2,
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"del": 3, // 10
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"div": 3,
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"ins": 3, // 12
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"pre": 3,
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"form": 4,
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"math": 4,
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"table": 5,
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"iframe": 6,
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"script": 6,
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"fieldset": 8,
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"noscript": 8,
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"blockquote": 10,
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}
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// functions for rendering parsed data
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type mkd_renderer struct {
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// block-level callbacks---nil skips the block
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blockcode func(ob *bytes.Buffer, text []byte, lang string, opaque interface{})
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blockquote func(ob *bytes.Buffer, text []byte, opaque interface{})
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blockhtml func(ob *bytes.Buffer, text []byte, opaque interface{})
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header func(ob *bytes.Buffer, text []byte, level int, opaque interface{})
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hrule func(ob *bytes.Buffer, opaque interface{})
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list func(ob *bytes.Buffer, text []byte, flags int, opaque interface{})
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listitem func(ob *bytes.Buffer, text []byte, flags int, opaque interface{})
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paragraph func(ob *bytes.Buffer, text []byte, opaque interface{})
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table func(ob *bytes.Buffer, header []byte, body []byte, opaque interface{})
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table_row func(ob *bytes.Buffer, text []byte, opaque interface{})
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table_cell func(ob *bytes.Buffer, text []byte, flags int, opaque interface{})
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// span-level callbacks---nil or return 0 prints the span verbatim
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autolink func(ob *bytes.Buffer, link []byte, kind int, opaque interface{}) int
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codespan func(ob *bytes.Buffer, text []byte, opaque interface{}) int
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double_emphasis func(ob *bytes.Buffer, text []byte, opaque interface{}) int
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emphasis func(ob *bytes.Buffer, text []byte, opaque interface{}) int
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image func(ob *bytes.Buffer, link []byte, title []byte, alt []byte, opaque interface{}) int
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linebreak func(ob *bytes.Buffer, opaque interface{}) int
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link func(ob *bytes.Buffer, link []byte, title []byte, content []byte, opaque interface{}) int
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raw_html_tag func(ob *bytes.Buffer, tag []byte, opaque interface{}) int
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triple_emphasis func(ob *bytes.Buffer, text []byte, opaque interface{}) int
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strikethrough func(ob *bytes.Buffer, text []byte, opaque interface{}) int
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// low-level callbacks---nil copies input directly into the output
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entity func(ob *bytes.Buffer, entity []byte, opaque interface{})
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normal_text func(ob *bytes.Buffer, text []byte, opaque interface{})
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// header and footer
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doc_header func(ob *bytes.Buffer, opaque interface{})
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doc_footer func(ob *bytes.Buffer, opaque interface{})
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// user data---passed back to every callback
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opaque interface{}
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}
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type link_ref struct {
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id []byte
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link []byte
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title []byte
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}
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type link_ref_array []*link_ref
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// implement the sorting interface
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func (elt link_ref_array) Len() int {
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return len(elt)
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}
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func (elt link_ref_array) Less(i, j int) bool {
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a, b := elt[i].id, elt[j].id
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// adapted from bytes.Compare in stdlib
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m := len(a)
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if m > len(b) {
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m = len(b)
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}
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for i, ac := range a[0:m] {
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// do a case-insensitive comparison
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ai, bi := unicode.ToLower(int(ac)), unicode.ToLower(int(b[i]))
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switch {
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case ai > bi:
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return false
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case ai < bi:
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return true
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}
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}
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switch {
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case len(a) < len(b):
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return true
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case len(a) > len(b):
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return false
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}
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return false
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}
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func (elt link_ref_array) Swap(i, j int) {
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elt[i], elt[j] = elt[j], elt[i]
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}
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// returns whether or not a line is a reference
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func is_ref(data []byte, beg int, last *int, rndr *render) bool {
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// up to 3 optional leading spaces
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if beg+3 > len(data) {
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return false
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}
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i := 0
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if data[beg] == ' ' {
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i++
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if data[beg+1] == ' ' {
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i++
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if data[beg+2] == ' ' {
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i++
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if data[beg+3] == ' ' {
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return false
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}
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}
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}
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}
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i += beg
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// id part: anything but a newline between brackets
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if data[i] != '[' {
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return false
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}
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i++
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id_offset := i
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for i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != ']' {
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i++
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}
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if i >= len(data) || data[i] != ']' {
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return false
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}
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id_end := i
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// spacer: colon (space | tab)* newline? (space | tab)*
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i++
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if i >= len(data) || data[i] != ':' {
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return false
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}
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i++
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for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
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i++
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}
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if i < len(data) && (data[i] == '\n' || data[i] == '\r') {
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i++
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if i < len(data) && data[i] == '\r' && data[i-1] == '\n' {
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i++
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}
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}
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for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
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i++
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}
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if i >= len(data) {
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return false
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}
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// link: whitespace-free sequence, optionally between angle brackets
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if data[i] == '<' {
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i++
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}
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link_offset := i
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for i < len(data) && data[i] != ' ' && data[i] != '\t' && data[i] != '\n' && data[i] != '\r' {
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i++
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}
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var link_end int
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if data[i-1] == '>' {
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link_end = i - 1
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} else {
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link_end = i
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}
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// optional spacer: (space | tab)* (newline | '\'' | '"' | '(' )
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for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
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i++
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}
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if i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != '\'' && data[i] != '"' && data[i] != '(' {
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return false
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}
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// compute end-of-line
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line_end := 0
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if i >= len(data) || data[i] == '\r' || data[i] == '\n' {
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line_end = i
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}
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if i+1 < len(data) && data[i] == '\n' && data[i+1] == '\r' {
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line_end = i + 1
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}
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// optional (space|tab)* spacer after a newline
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if line_end > 0 {
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i = line_end + 1
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for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
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i++
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}
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}
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// optional title: any non-newline sequence enclosed in '"() alone on its line
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title_offset, title_end := 0, 0
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if i+1 < len(data) && (data[i] == '\'' || data[i] == '"' || data[i] == '(') {
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i++
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title_offset = i
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// looking for EOL
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for i < len(data) && data[i] != '\n' && data[i] != '\r' {
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i++
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}
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if i+1 < len(data) && data[i] == '\n' && data[i+1] == '\r' {
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title_end = i + 1
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} else {
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title_end = i
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}
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// stepping back
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i--
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for i > title_offset && (data[i] == ' ' || data[i] == '\t') {
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i--
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}
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if i > title_offset && (data[i] == '\'' || data[i] == '"' || data[i] == ')') {
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line_end = title_end
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title_end = i
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}
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}
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if line_end == 0 { // garbage after the link
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return false
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}
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// a valid ref has been found; fill in return structures
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if last != nil {
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*last = line_end
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}
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if rndr == nil {
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return true
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}
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item := &link_ref{id: data[id_offset:id_end], link: data[link_offset:link_end], title: data[title_offset:title_end]}
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rndr.refs = append(rndr.refs, item)
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return true
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}
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type render struct {
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mk *mkd_renderer
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refs link_ref_array
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active_char [256]int
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ext_flags uint32
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nesting int
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max_nesting int
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}
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const (
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MD_CHAR_NONE = iota
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MD_CHAR_EMPHASIS
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MD_CHAR_CODESPAN
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MD_CHAR_LINEBREAK
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MD_CHAR_LINK
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MD_CHAR_LANGLE
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MD_CHAR_ESCAPE
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MD_CHAR_ENTITITY
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MD_CHAR_AUTOLINK
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)
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// closures to render active chars, each:
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// returns the number of chars taken care of
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// data is the complete block being rendered
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// offset is the number of valid chars before the data
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//
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// Note: this is filled in in Markdown to prevent an initilization loop
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var markdown_char_ptrs [9]func(ob *bytes.Buffer, rndr *render, data []byte, offset int) int
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func parse_inline(ob *bytes.Buffer, rndr *render, data []byte) {
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if rndr.nesting >= rndr.max_nesting {
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return
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}
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rndr.nesting++
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i, end := 0, 0
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for i < len(data) {
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// copy inactive chars into the output
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for end < len(data) && rndr.active_char[data[end]] == 0 {
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end++
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}
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if rndr.mk.normal_text != nil {
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rndr.mk.normal_text(ob, data[i:], rndr.mk.opaque)
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} else {
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ob.Write(data[i:])
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}
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if end >= len(data) {
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break
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}
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i = end
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// call the trigger
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action := rndr.active_char[data[end]]
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end = markdown_char_ptrs[action](ob, rndr, data, i)
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if end == 0 { // no action from the callback
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end = i + 1
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} else {
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i += end
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end = i
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}
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}
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rndr.nesting--
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}
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// single and double emphasis parsing
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func char_emphasis(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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c := data[0]
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ret := 0
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if len(data) > 2 && data[1] != c {
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// whitespace cannot follow an opening emphasis;
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// strikethrough only takes two characters '~~'
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if c == '~' || unicode.IsSpace(int(data[1])) {
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return 0
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}
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if ret = parse_emph1(ob, rndr, data[1:], c); ret == 0 {
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return 0
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}
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return ret + 1
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}
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if len(data) > 3 && data[1] == c && data[2] != c {
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if unicode.IsSpace(int(data[2])) {
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return 0
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}
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if ret = parse_emph2(ob, rndr, data[2:], c); ret == 0 {
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return 0
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}
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return ret + 2
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}
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if len(data) > 4 && data[1] == c && data[2] == c && data[3] != c {
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if c == '~' || unicode.IsSpace(int(data[3])) {
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return 0
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}
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if ret = parse_emph3(ob, rndr, data, 3, c); ret == 0 {
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return 0
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}
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return ret + 3
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}
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return 0
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}
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func char_codespan(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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return 0
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}
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func char_linebreak(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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return 0
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}
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func char_link(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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return 0
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}
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func char_langle_tag(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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return 0
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}
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func char_escape(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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return 0
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}
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func char_entity(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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data = data[offset:]
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return 0
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}
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func char_autolink(ob *bytes.Buffer, rndr *render, data []byte, offset int) int {
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//orig_data := data
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data = data[offset:]
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return 0
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}
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// taken from regexp in the stdlib
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func ispunct(c int) bool {
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for _, r := range "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~" {
|
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if c == r {
|
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return true
|
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}
|
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}
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return false
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}
|
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|
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// look for the next emph char, skipping other constructs
|
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func find_emph_char(data []byte, c byte) int {
|
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i := 1
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|
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for i < len(data) {
|
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for i < len(data) && data[i] != c && data[i] != '`' && data[i] != '[' {
|
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i++
|
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}
|
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if data[i] == c {
|
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return i
|
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}
|
|
|
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// do not count escaped chars
|
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if i != 0 && data[i-1] == '\\' {
|
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i++
|
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continue
|
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}
|
|
|
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if data[i] == '`' {
|
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// skip a code span
|
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tmp_i := 0
|
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i++
|
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for i < len(data) && data[i] != '`' {
|
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if tmp_i == 0 && data[i] == c {
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tmp_i = i
|
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}
|
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i++
|
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}
|
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if i >= len(data) {
|
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return tmp_i
|
|
}
|
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i++
|
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} else {
|
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if data[i] == '[' {
|
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// skip a link
|
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tmp_i := 0
|
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i++
|
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for i < len(data) && data[i] != ']' {
|
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if tmp_i == 0 && data[i] == c {
|
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tmp_i = i
|
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}
|
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i++
|
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}
|
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i++
|
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for i < len(data) && (data[i] == ' ' || data[i] == '\t' || data[i] == '\n') {
|
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i++
|
|
}
|
|
if i >= len(data) {
|
|
return tmp_i
|
|
}
|
|
if data[i] != '[' && data[i] != '(' { // not a link
|
|
if tmp_i > 0 {
|
|
return tmp_i
|
|
} else {
|
|
continue
|
|
}
|
|
}
|
|
cc := data[i]
|
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i++
|
|
for i < len(data) && data[i] != cc {
|
|
if tmp_i == 0 && data[i] == c {
|
|
tmp_i = i
|
|
}
|
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i++
|
|
}
|
|
if i >= len(data) {
|
|
return tmp_i
|
|
}
|
|
i++
|
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}
|
|
}
|
|
}
|
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return 0
|
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}
|
|
|
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func parse_emph1(ob *bytes.Buffer, rndr *render, data []byte, c byte) int {
|
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i := 0
|
|
|
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if rndr.mk.emphasis == nil {
|
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return 0
|
|
}
|
|
|
|
// skip one symbol if coming from emph3
|
|
if len(data) > 1 && data[0] == c && data[1] == c {
|
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i = 1
|
|
}
|
|
|
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for i < len(data) {
|
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length := find_emph_char(data[i:], c)
|
|
if length == 0 {
|
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return 0
|
|
}
|
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i += length
|
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if i >= len(data) {
|
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return 0
|
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}
|
|
|
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if i+1 < len(data) && data[i+1] == c {
|
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i++
|
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continue
|
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}
|
|
|
|
if data[i] == c && !unicode.IsSpace(int(data[i-1])) {
|
|
|
|
if rndr.ext_flags&MKDEXT_NO_INTRA_EMPHASIS != 0 {
|
|
if !(i+1 == len(data) || unicode.IsSpace(int(data[i+1])) || ispunct(int(data[i+1]))) {
|
|
continue
|
|
}
|
|
}
|
|
|
|
work := bytes.NewBuffer(nil)
|
|
parse_inline(work, rndr, data[:i])
|
|
r := rndr.mk.emphasis(ob, work.Bytes(), rndr.mk.opaque)
|
|
if r > 0 {
|
|
return i + 1
|
|
} else {
|
|
return 0
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0
|
|
}
|
|
|
|
func parse_emph2(ob *bytes.Buffer, rndr *render, data []byte, c byte) int {
|
|
render_method := rndr.mk.double_emphasis
|
|
if c == '~' {
|
|
render_method = rndr.mk.strikethrough
|
|
}
|
|
|
|
if render_method == nil {
|
|
return 0
|
|
}
|
|
|
|
i := 0
|
|
|
|
for i < len(data) {
|
|
length := find_emph_char(data[i:], c)
|
|
if length == 0 {
|
|
return 0
|
|
}
|
|
i += length
|
|
|
|
if i+1 < len(data) && data[i] == c && data[i+1] == c && i > 0 && !unicode.IsSpace(int(data[i-1])) {
|
|
work := bytes.NewBuffer(nil)
|
|
parse_inline(work, rndr, data[:i])
|
|
r := render_method(ob, work.Bytes(), rndr.mk.opaque)
|
|
if r > 0 {
|
|
return i + 2
|
|
} else {
|
|
return 0
|
|
}
|
|
}
|
|
i++
|
|
}
|
|
return 0
|
|
}
|
|
|
|
func parse_emph3(ob *bytes.Buffer, rndr *render, data []byte, offset int, c byte) int {
|
|
i := 0
|
|
orig_data := data
|
|
data = data[offset:]
|
|
|
|
for i < len(data) {
|
|
length := find_emph_char(data[i:], c)
|
|
if length == 0 {
|
|
return 0
|
|
}
|
|
i += length
|
|
|
|
// skip whitespace preceded symbols
|
|
if data[i] != c || unicode.IsSpace(int(data[i-1])) {
|
|
continue
|
|
}
|
|
|
|
switch {
|
|
case (i+2 < len(data) && data[i+1] == c && data[i+2] == c && rndr.mk.triple_emphasis != nil):
|
|
// triple symbol found
|
|
work := bytes.NewBuffer(nil)
|
|
|
|
parse_inline(work, rndr, data[:i])
|
|
r := rndr.mk.triple_emphasis(ob, work.Bytes(), rndr.mk.opaque)
|
|
if r > 0 {
|
|
return i + 3
|
|
} else {
|
|
return 0
|
|
}
|
|
case (i+1 < len(data) && data[i+1] == c):
|
|
// double symbol found, handing over to emph1
|
|
length = parse_emph1(ob, rndr, orig_data[offset-2:], c)
|
|
if length == 0 {
|
|
return 0
|
|
} else {
|
|
return length - 2
|
|
}
|
|
default:
|
|
// single symbol found, handing over to emph2
|
|
length = parse_emph2(ob, rndr, orig_data[offset-1:], c)
|
|
if length == 0 {
|
|
return 0
|
|
} else {
|
|
return length - 1
|
|
}
|
|
}
|
|
}
|
|
return 0
|
|
}
|
|
|
|
// parse block-level data
|
|
func parse_block(ob *bytes.Buffer, rndr *render, data []byte) {
|
|
if rndr.nesting >= rndr.max_nesting {
|
|
return
|
|
}
|
|
rndr.nesting++
|
|
|
|
for len(data) > 0 {
|
|
if is_atxheader(rndr, data) {
|
|
data = data[parse_atxheader(ob, rndr, data):]
|
|
continue
|
|
}
|
|
if data[0] == '<' && rndr.mk.blockhtml != nil {
|
|
if i := parse_htmlblock(ob, rndr, data, true); i > 0 {
|
|
data = data[i:]
|
|
continue
|
|
}
|
|
}
|
|
if i := is_empty(data); i > 0 {
|
|
data = data[i:]
|
|
continue
|
|
}
|
|
if is_hrule(data) {
|
|
if rndr.mk.hrule != nil {
|
|
rndr.mk.hrule(ob, rndr.mk.opaque)
|
|
}
|
|
var i int
|
|
for i = 0; i < len(data) && data[i] != '\n'; i++ {
|
|
}
|
|
data = data[i:]
|
|
continue
|
|
}
|
|
if rndr.ext_flags&MKDEXT_FENCED_CODE != 0 {
|
|
if i := parse_fencedcode(ob, rndr, data); i > 0 {
|
|
data = data[i:]
|
|
continue
|
|
}
|
|
}
|
|
if rndr.ext_flags&MKDEXT_TABLES != 0 {
|
|
if i := parse_table(ob, rndr, data); i > 0 {
|
|
data = data[i:]
|
|
continue
|
|
}
|
|
}
|
|
if prefix_quote(data) > 0 {
|
|
data = data[parse_blockquote(ob, rndr, data):]
|
|
continue
|
|
}
|
|
if prefix_code(data) > 0 {
|
|
data = data[parse_blockcode(ob, rndr, data):]
|
|
continue
|
|
}
|
|
if prefix_uli(data) > 0 {
|
|
data = data[parse_list(ob, rndr, data, 0):]
|
|
continue
|
|
}
|
|
if prefix_oli(data) > 0 {
|
|
data = data[parse_list(ob, rndr, data, MKD_LIST_ORDERED):]
|
|
continue
|
|
}
|
|
|
|
data = data[parse_paragraph(ob, rndr, data):]
|
|
}
|
|
|
|
rndr.nesting--
|
|
}
|
|
|
|
func is_atxheader(rndr *render, data []byte) bool {
|
|
if data[0] != '#' {
|
|
return false
|
|
}
|
|
|
|
if rndr.ext_flags&MKDEXT_SPACE_HEADERS != 0 {
|
|
level := 0
|
|
for level < len(data) && level < 6 && data[level] == '#' {
|
|
level++
|
|
}
|
|
if level < len(data) && data[level] != ' ' && data[level] != '\t' {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
func parse_atxheader(ob *bytes.Buffer, rndr *render, data []byte) int {
|
|
level := 0
|
|
for level < len(data) && level < 6 && data[level] == '#' {
|
|
level++
|
|
}
|
|
i, end := 0, 0
|
|
for i = level; i < len(data) && (data[i] == ' ' || data[i] == '\t'); i++ {
|
|
}
|
|
for end = i; end < len(data) && data[end] != '\n'; end++ {
|
|
}
|
|
skip := end
|
|
for end > 0 && data[end-1] == '#' {
|
|
end--
|
|
}
|
|
for end > 0 && (data[end-1] == ' ' || data[end-1] == '\t') {
|
|
end--
|
|
}
|
|
if end > i {
|
|
work := bytes.NewBuffer(nil)
|
|
parse_inline(work, rndr, data[i:end])
|
|
if rndr.mk.header != nil {
|
|
rndr.mk.header(ob, work.Bytes(), level, rndr.mk.opaque)
|
|
}
|
|
}
|
|
return skip
|
|
}
|
|
|
|
func is_headerline(data []byte) int {
|
|
i := 0
|
|
|
|
// test of level 1 header
|
|
if data[i] == '=' {
|
|
for i = 1; i < len(data) && data[i] == '='; i++ {
|
|
}
|
|
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
|
i++
|
|
}
|
|
if i >= len(data) || data[i] == '\n' {
|
|
return 1
|
|
} else {
|
|
return 0
|
|
}
|
|
}
|
|
|
|
// test of level 2 header
|
|
if data[i] == '-' {
|
|
for i = 1; i < len(data) && data[i] == '-'; i++ {
|
|
}
|
|
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
|
i++
|
|
}
|
|
if i >= len(data) || data[i] == '\n' {
|
|
return 2
|
|
} else {
|
|
return 0
|
|
}
|
|
}
|
|
|
|
return 0
|
|
}
|
|
|
|
func parse_htmlblock(ob *bytes.Buffer, rndr *render, data []byte, do_render bool) int {
|
|
var i, j int
|
|
|
|
// identify the opening tag
|
|
if len(data) < 2 || data[0] != '<' {
|
|
return 0
|
|
}
|
|
curtag, tagfound := find_block_tag(data[1:])
|
|
|
|
// handle special cases
|
|
if !tagfound {
|
|
|
|
// HTML comment, laxist form
|
|
if len(data) > 5 && data[1] == '!' && data[2] == '-' && data[3] == '-' {
|
|
i = 5
|
|
|
|
for i < len(data) && !(data[i-2] == '-' && data[i-1] == '-' && data[i] == '>') {
|
|
i++
|
|
}
|
|
i++
|
|
|
|
if i < len(data) {
|
|
j = is_empty(data[i:])
|
|
}
|
|
|
|
if j > 0 {
|
|
size := i + j
|
|
if do_render && rndr.mk.blockhtml != nil {
|
|
rndr.mk.blockhtml(ob, data[:size], rndr.mk.opaque)
|
|
}
|
|
return size
|
|
}
|
|
}
|
|
|
|
// HR, which is the only self-closing block tag considered
|
|
if len(data) > 4 && (data[i] == 'h' || data[1] == 'H') && (data[2] == 'r' || data[2] == 'R') {
|
|
i = 3
|
|
for i < len(data) && data[i] != '>' {
|
|
i++
|
|
}
|
|
|
|
if i+1 < len(data) {
|
|
i++
|
|
j = is_empty(data[i:])
|
|
if j > 0 {
|
|
size := i + j
|
|
if do_render && rndr.mk.blockhtml != nil {
|
|
rndr.mk.blockhtml(ob, data[:size], rndr.mk.opaque)
|
|
}
|
|
return size
|
|
}
|
|
}
|
|
}
|
|
|
|
// no special case recognized
|
|
return 0
|
|
}
|
|
|
|
// look for an unindented matching closing tag
|
|
// followed by a blank line
|
|
i = 1
|
|
found := false
|
|
|
|
// if not found, try a second pass looking for indented match
|
|
// but not if tag is "ins" or "del" (following original Markdown.pl)
|
|
if curtag != "ins" && curtag != "del" {
|
|
i = 1
|
|
for i < len(data) {
|
|
i++
|
|
for i < len(data) && !(data[i-1] == '<' && data[i] == '/') {
|
|
i++
|
|
}
|
|
|
|
if i+2+len(curtag) >= len(data) {
|
|
break
|
|
}
|
|
|
|
j = htmlblock_end(curtag, rndr, data[i-1:])
|
|
|
|
if j > 0 {
|
|
i += j - 1
|
|
found = true
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
if !found {
|
|
return 0
|
|
}
|
|
|
|
// the end of the block has been found
|
|
if do_render && rndr.mk.blockhtml != nil {
|
|
rndr.mk.blockhtml(ob, data[:i], rndr.mk.opaque)
|
|
}
|
|
|
|
return i
|
|
}
|
|
|
|
func find_block_tag(data []byte) (string, bool) {
|
|
i := 0
|
|
for i < len(data) && ((data[i] >= '0' && data[i] <= '9') || (data[i] >= 'A' && data[i] <= 'Z') || (data[i] >= 'a' && data[i] <= 'z')) {
|
|
i++
|
|
}
|
|
if i >= len(data) {
|
|
return "", false
|
|
}
|
|
key := string(data[:i])
|
|
if _, ok := block_tags[key]; ok {
|
|
return key, true
|
|
}
|
|
return "", false
|
|
}
|
|
|
|
func htmlblock_end(tag string, rndr *render, data []byte) int {
|
|
// assume data[0] == '<' && data[1] == '/' already tested
|
|
|
|
// check if tag is a match
|
|
if len(tag)+3 >= len(data) || bytes.Compare(data[2:2+len(tag)], []byte(tag)) != 0 || data[len(tag)+2] != '>' {
|
|
return 0
|
|
}
|
|
|
|
// check white lines
|
|
i := len(tag) + 3
|
|
w := 0
|
|
if i < len(data) {
|
|
if w = is_empty(data[i:]); w == 0 {
|
|
return 0 // non-blank after tag
|
|
}
|
|
}
|
|
i += w
|
|
w = 0
|
|
|
|
if rndr.ext_flags&MKDEXT_LAX_HTML_BLOCKS != 0 {
|
|
if i < len(data) {
|
|
w = is_empty(data[i:])
|
|
}
|
|
} else {
|
|
if i < len(data) {
|
|
if w = is_empty(data[i:]); w == 0 {
|
|
return 0 // non-blank line after tag line
|
|
}
|
|
}
|
|
}
|
|
|
|
return i + w
|
|
}
|
|
|
|
func is_empty(data []byte) int {
|
|
var i int
|
|
for i = 0; i < len(data) && data[i] != '\n'; i++ {
|
|
if data[i] != ' ' && data[i] != '\t' {
|
|
return 0
|
|
}
|
|
}
|
|
return i + 1
|
|
}
|
|
|
|
func is_hrule(data []byte) bool {
|
|
// skip initial spaces
|
|
if len(data) < 3 {
|
|
return false
|
|
}
|
|
i := 0
|
|
if data[0] == ' ' {
|
|
i++
|
|
if data[1] == ' ' {
|
|
i++
|
|
if data[2] == ' ' {
|
|
i++
|
|
}
|
|
}
|
|
}
|
|
|
|
// look at the hrule char
|
|
if i+2 >= len(data) || (data[i] != '*' && data[i] != '-' && data[i] != '_') {
|
|
return false
|
|
}
|
|
c := data[i]
|
|
|
|
// the whole line must be the char or whitespace
|
|
n := 0
|
|
for i < len(data) && data[i] != '\n' {
|
|
switch {
|
|
case data[i] == c:
|
|
n++
|
|
case data[i] != ' ' && data[i] != '\t':
|
|
return false
|
|
}
|
|
i++
|
|
}
|
|
|
|
return n >= 3
|
|
}
|
|
|
|
func is_codefence(data []byte, syntax **string) int {
|
|
i, n := 0, 0
|
|
|
|
// skip initial spaces
|
|
if len(data) < 3 {
|
|
return 0
|
|
}
|
|
if data[0] == ' ' {
|
|
i++
|
|
if data[1] == ' ' {
|
|
i++
|
|
if data[2] == ' ' {
|
|
i++
|
|
}
|
|
}
|
|
}
|
|
|
|
// look at the hrule char
|
|
if i+2 >= len(data) || !(data[i] == '~' || data[i] == '`') {
|
|
return 0
|
|
}
|
|
|
|
c := data[i]
|
|
|
|
// the whole line must be the char or whitespace
|
|
for i < len(data) && data[i] == c {
|
|
n++
|
|
i++
|
|
}
|
|
|
|
if n < 3 {
|
|
return 0
|
|
}
|
|
|
|
if syntax != nil {
|
|
syn := 0
|
|
|
|
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
|
i++
|
|
}
|
|
|
|
syntax_start := i
|
|
|
|
if i < len(data) && data[i] == '{' {
|
|
i++
|
|
syntax_start++
|
|
|
|
for i < len(data) && data[i] != '}' && data[i] != '\n' {
|
|
syn++
|
|
i++
|
|
}
|
|
|
|
if i == len(data) || data[i] != '}' {
|
|
return 0
|
|
}
|
|
|
|
// string all whitespace at the beginning and the end
|
|
// of the {} block
|
|
for syn > 0 && unicode.IsSpace(int(data[syntax_start])) {
|
|
syntax_start++
|
|
syn--
|
|
}
|
|
|
|
for syn > 0 && unicode.IsSpace(int(data[syntax_start+syn-1])) {
|
|
syn--
|
|
}
|
|
|
|
i++
|
|
} else {
|
|
for i < len(data) && !unicode.IsSpace(int(data[i])) {
|
|
syn++
|
|
i++
|
|
}
|
|
}
|
|
|
|
language := string(data[syntax_start : syntax_start+syn])
|
|
*syntax = &language
|
|
}
|
|
|
|
for i < len(data) && data[i] != '\n' {
|
|
if !unicode.IsSpace(int(data[i])) {
|
|
return 0
|
|
}
|
|
i++
|
|
}
|
|
|
|
return i + 1
|
|
}
|
|
|
|
func parse_fencedcode(ob *bytes.Buffer, rndr *render, data []byte) int {
|
|
var lang *string
|
|
beg := is_codefence(data, &lang)
|
|
if beg == 0 {
|
|
return 0
|
|
}
|
|
|
|
work := bytes.NewBuffer(nil)
|
|
|
|
for beg < len(data) {
|
|
fence_end := is_codefence(data[beg:], nil)
|
|
if fence_end != 0 {
|
|
beg += fence_end
|
|
break
|
|
}
|
|
|
|
var end int
|
|
for end = beg + 1; end < len(data) && data[end-1] != '\n'; end++ {
|
|
}
|
|
|
|
if beg < end {
|
|
// verbatim copy to the working buffer, escaping entities
|
|
if is_empty(data[beg:]) > 0 {
|
|
work.WriteByte('\n')
|
|
} else {
|
|
work.Write(data[beg:end])
|
|
}
|
|
}
|
|
beg = end
|
|
}
|
|
|
|
if work.Len() > 0 && work.Bytes()[work.Len()-1] != '\n' {
|
|
work.WriteByte('\n')
|
|
}
|
|
|
|
if rndr.mk.blockcode != nil {
|
|
syntax := ""
|
|
if lang != nil {
|
|
syntax = *lang
|
|
}
|
|
|
|
rndr.mk.blockcode(ob, work.Bytes(), syntax, rndr.mk.opaque)
|
|
}
|
|
|
|
return beg
|
|
}
|
|
|
|
func parse_table(ob *bytes.Buffer, rndr *render, data []byte) int {
|
|
header_work := bytes.NewBuffer(nil)
|
|
i, columns, col_data := parse_table_header(header_work, rndr, data)
|
|
if i > 0 {
|
|
body_work := bytes.NewBuffer(nil)
|
|
|
|
for i < len(data) {
|
|
pipes, row_start := 0, i
|
|
for ; i < len(data) && data[i] != '\n'; i++ {
|
|
if data[i] == '|' {
|
|
pipes++
|
|
}
|
|
}
|
|
|
|
if pipes == 0 || i == len(data) {
|
|
i = row_start
|
|
break
|
|
}
|
|
|
|
parse_table_row(body_work, rndr, data[row_start:i], columns, col_data)
|
|
i++
|
|
}
|
|
|
|
if rndr.mk.table != nil {
|
|
rndr.mk.table(ob, header_work.Bytes(), body_work.Bytes(), rndr.mk.opaque)
|
|
}
|
|
}
|
|
|
|
return i
|
|
}
|
|
|
|
func parse_table_header(ob *bytes.Buffer, rndr *render, data []byte) (size int, columns int, column_data []int) {
|
|
i, pipes := 0, 0
|
|
column_data = []int{}
|
|
for i = 0; i < len(data) && data[i] != '\n'; i++ {
|
|
if data[i] == '|' {
|
|
pipes++
|
|
}
|
|
}
|
|
|
|
if i == len(data) || pipes == 0 {
|
|
return 0, 0, column_data
|
|
}
|
|
|
|
header_end := i
|
|
|
|
if data[0] == '|' {
|
|
pipes--
|
|
}
|
|
|
|
if i > 2 && data[i-1] == '|' {
|
|
pipes--
|
|
}
|
|
|
|
columns = pipes + 1
|
|
column_data = make([]int, columns)
|
|
|
|
// parse the header underline
|
|
i++
|
|
if i < len(data) && data[i] == '|' {
|
|
i++
|
|
}
|
|
|
|
under_end := i
|
|
for under_end < len(data) && data[under_end] != '\n' {
|
|
under_end++
|
|
}
|
|
|
|
col := 0
|
|
for ; col < columns && i < under_end; col++ {
|
|
dashes := 0
|
|
|
|
for i < under_end && (data[i] == ' ' || data[i] == '\t') {
|
|
i++
|
|
}
|
|
|
|
if data[i] == ':' {
|
|
i++
|
|
column_data[col] |= MKD_TABLE_ALIGN_L
|
|
dashes++
|
|
}
|
|
|
|
for i < under_end && data[i] == '-' {
|
|
i++
|
|
dashes++
|
|
}
|
|
|
|
if i < under_end && data[i] == ':' {
|
|
i++
|
|
column_data[col] |= MKD_TABLE_ALIGN_R
|
|
dashes++
|
|
}
|
|
|
|
for i < under_end && (data[i] == ' ' || data[i] == '\t') {
|
|
i++
|
|
}
|
|
|
|
if i < under_end && data[i] != '|' {
|
|
break
|
|
}
|
|
|
|
if dashes < 3 {
|
|
break
|
|
}
|
|
|
|
i++
|
|
}
|
|
|
|
if col < columns {
|
|
return 0, 0, column_data
|
|
}
|
|
|
|
parse_table_row(ob, rndr, data[:header_end], columns, column_data)
|
|
size = under_end + 1
|
|
return
|
|
}
|
|
|
|
func parse_table_row(ob *bytes.Buffer, rndr *render, data []byte, columns int, col_data []int) {
|
|
i, col := 0, 0
|
|
row_work := bytes.NewBuffer(nil)
|
|
|
|
if i < len(data) && data[i] == '|' {
|
|
i++
|
|
}
|
|
|
|
for col = 0; col < columns && i < len(data); col++ {
|
|
for i < len(data) && unicode.IsSpace(int(data[i])) {
|
|
i++
|
|
}
|
|
|
|
cell_start := i
|
|
|
|
for i < len(data) && data[i] != '|' {
|
|
i++
|
|
}
|
|
|
|
cell_end := i - 1
|
|
|
|
for cell_end > cell_start && unicode.IsSpace(int(data[cell_end])) {
|
|
cell_end--
|
|
}
|
|
|
|
cell_work := bytes.NewBuffer(nil)
|
|
parse_inline(cell_work, rndr, data[cell_start:cell_end+1])
|
|
|
|
if rndr.mk.table_cell != nil {
|
|
cdata := 0
|
|
if col < len(col_data) {
|
|
cdata = col_data[col]
|
|
}
|
|
rndr.mk.table_cell(row_work, cell_work.Bytes(), cdata, rndr.mk.opaque)
|
|
}
|
|
|
|
i++
|
|
}
|
|
|
|
for ; col < columns; col++ {
|
|
empty_cell := []byte{}
|
|
if rndr.mk.table_cell != nil {
|
|
cdata := 0
|
|
if col < len(col_data) {
|
|
cdata = col_data[col]
|
|
}
|
|
rndr.mk.table_cell(row_work, empty_cell, cdata, rndr.mk.opaque)
|
|
}
|
|
}
|
|
|
|
if rndr.mk.table_row != nil {
|
|
rndr.mk.table_row(ob, row_work.Bytes(), rndr.mk.opaque)
|
|
}
|
|
}
|
|
|
|
// returns blockquote prefix length
|
|
func prefix_quote(data []byte) int {
|
|
i := 0
|
|
for i < len(data) && i < 3 && data[i] == ' ' {
|
|
i++
|
|
}
|
|
if i < len(data) && data[i] == '>' {
|
|
if i+1 < len(data) && (data[i+1] == ' ' || data[i+1] == '\t') {
|
|
return i + 2
|
|
}
|
|
return i + 1
|
|
}
|
|
return 0
|
|
}
|
|
|
|
// handles parsing of a blockquote fragment
|
|
func parse_blockquote(ob *bytes.Buffer, rndr *render, data []byte) int {
|
|
out := bytes.NewBuffer(nil)
|
|
work := bytes.NewBuffer(nil)
|
|
beg, end := 0, 0
|
|
for beg < len(data) {
|
|
for end = beg + 1; end < len(data) && data[end-1] != '\n'; end++ {
|
|
}
|
|
|
|
if pre := prefix_quote(data[beg:]); pre > 0 {
|
|
beg += pre // skip prefix
|
|
} else {
|
|
// empty line followed by non-quote line
|
|
if is_empty(data[beg:]) > 0 && (end >= len(data) || (prefix_quote(data[end:]) == 0 && is_empty(data[end:]) == 0)) {
|
|
break
|
|
}
|
|
}
|
|
|
|
if beg < end { // copy into the in-place working buffer
|
|
work.Write(data[beg:end])
|
|
}
|
|
beg = end
|
|
}
|
|
|
|
parse_block(out, rndr, work.Bytes())
|
|
if rndr.mk.blockquote != nil {
|
|
rndr.mk.blockquote(ob, out.Bytes(), rndr.mk.opaque)
|
|
}
|
|
return end
|
|
}
|
|
|
|
// returns prefix length for block code
|
|
func prefix_code(data []byte) int {
|
|
if len(data) > 0 && data[0] == '\t' {
|
|
return 1
|
|
}
|
|
if len(data) > 3 && data[0] == ' ' && data[1] == ' ' && data[2] == ' ' && data[3] == ' ' {
|
|
return 4
|
|
}
|
|
return 0
|
|
}
|
|
|
|
func parse_blockcode(ob *bytes.Buffer, rndr *render, data []byte) int {
|
|
work := bytes.NewBuffer(nil)
|
|
|
|
beg, end := 0, 0
|
|
for beg < len(data) {
|
|
for end = beg + 1; end < len(data) && data[end-1] != '\n'; end++ {
|
|
}
|
|
|
|
chunk := data[beg:end]
|
|
if pre := prefix_code(chunk); pre > 0 {
|
|
beg += pre
|
|
} else {
|
|
if is_empty(chunk) == 0 {
|
|
// non-empty non-prefixed line breaks the pre
|
|
break
|
|
}
|
|
}
|
|
|
|
if beg < end {
|
|
// verbatim copy to the working buffer, escaping entities
|
|
if is_empty(chunk) > 0 {
|
|
work.WriteByte('\n')
|
|
} else {
|
|
work.Write(chunk)
|
|
}
|
|
}
|
|
beg = end
|
|
}
|
|
|
|
// trim all the \n off the end of work
|
|
workbytes := work.Bytes()
|
|
n := 0
|
|
for len(workbytes) > n && workbytes[len(workbytes)-n-1] == '\n' {
|
|
n++
|
|
}
|
|
if n > 0 {
|
|
work = bytes.NewBuffer(workbytes[:len(workbytes)-n])
|
|
}
|
|
|
|
work.WriteByte('\n')
|
|
|
|
if rndr.mk.blockcode != nil {
|
|
rndr.mk.blockcode(ob, work.Bytes(), "", rndr.mk.opaque)
|
|
}
|
|
|
|
return beg
|
|
}
|
|
|
|
// returns unordered list item prefix
|
|
func prefix_uli(data []byte) int {
|
|
i := 0
|
|
for i < len(data) && i < 3 && data[i] == ' ' {
|
|
i++
|
|
}
|
|
if i+1 >= len(data) || (data[i] != '*' && data[i] != '+' && data[i] != '-') || (data[i+1] != ' ' && data[i+1] != '\t') {
|
|
return 0
|
|
}
|
|
return i + 2
|
|
}
|
|
|
|
// returns ordered list item prefix
|
|
func prefix_oli(data []byte) int {
|
|
i := 0
|
|
for i < len(data) && i < 3 && data[i] == ' ' {
|
|
i++
|
|
}
|
|
if i >= len(data) || data[i] < '0' || data[i] > '9' {
|
|
return 0
|
|
}
|
|
for i < len(data) && data[i] >= '0' && data[i] <= '9' {
|
|
i++
|
|
}
|
|
if i+1 >= len(data) || data[i] != '.' || (data[i+1] != ' ' && data[i+1] != '\t') {
|
|
return 0
|
|
}
|
|
return i + 2
|
|
}
|
|
|
|
// parsing ordered or unordered list block
|
|
func parse_list(ob *bytes.Buffer, rndr *render, data []byte, flags int) int {
|
|
work := bytes.NewBuffer(nil)
|
|
|
|
i, j := 0, 0
|
|
for i < len(data) {
|
|
j = parse_listitem(work, rndr, data[i:], &flags)
|
|
i += j
|
|
|
|
if j == 0 || flags&MKD_LI_END != 0 {
|
|
break
|
|
}
|
|
}
|
|
|
|
if rndr.mk.list != nil {
|
|
rndr.mk.list(ob, work.Bytes(), flags, rndr.mk.opaque)
|
|
}
|
|
return i
|
|
}
|
|
|
|
// parse a single list item
|
|
// assumes initial prefix is already removed
|
|
func parse_listitem(ob *bytes.Buffer, rndr *render, data []byte, flags *int) int {
|
|
// keep track of the first indentation prefix
|
|
beg, end, pre, sublist, orgpre, i := 0, 0, 0, 0, 0, 0
|
|
|
|
for orgpre < 3 && orgpre < len(data) && data[orgpre] == ' ' {
|
|
orgpre++
|
|
}
|
|
|
|
beg = prefix_uli(data)
|
|
if beg == 0 {
|
|
beg = prefix_oli(data)
|
|
}
|
|
if beg == 0 {
|
|
return 0
|
|
}
|
|
|
|
// skip to the beginning of the following line
|
|
end = beg
|
|
for end < len(data) && data[end-1] != '\n' {
|
|
end++
|
|
}
|
|
|
|
// get working buffers
|
|
work := bytes.NewBuffer(nil)
|
|
inter := bytes.NewBuffer(nil)
|
|
|
|
// put the first line into the working buffer
|
|
work.Write(data[beg:end])
|
|
beg = end
|
|
|
|
// process the following lines
|
|
in_empty, has_inside_empty := false, false
|
|
for beg < len(data) {
|
|
end++
|
|
|
|
for end < len(data) && data[end-1] != '\n' {
|
|
end++
|
|
}
|
|
|
|
// process an empty line
|
|
if is_empty(data[beg:end]) > 0 {
|
|
in_empty = true
|
|
beg = end
|
|
continue
|
|
}
|
|
|
|
// calculate the indentation
|
|
i = 0
|
|
for i < 4 && beg+i < end && data[beg+i] == ' ' {
|
|
i++
|
|
}
|
|
|
|
pre = i
|
|
if data[beg] == '\t' {
|
|
i = 1
|
|
pre = 8
|
|
}
|
|
|
|
// check for a new item
|
|
chunk := data[beg+i : end]
|
|
if (prefix_uli(chunk) > 0 && !is_hrule(chunk)) || prefix_oli(chunk) > 0 {
|
|
if in_empty {
|
|
has_inside_empty = true
|
|
}
|
|
|
|
if pre == orgpre { // the following item must have the same indentation
|
|
break
|
|
}
|
|
|
|
if sublist == 0 {
|
|
sublist = work.Len()
|
|
}
|
|
} else {
|
|
// only join indented stuff after empty lines
|
|
if in_empty && i < 4 && data[beg] != '\t' {
|
|
*flags |= MKD_LI_END
|
|
break
|
|
} else {
|
|
if in_empty {
|
|
work.WriteByte('\n')
|
|
has_inside_empty = true
|
|
}
|
|
}
|
|
}
|
|
|
|
in_empty = false
|
|
|
|
// add the line into the working buffer without prefix
|
|
work.Write(data[beg+i : end])
|
|
beg = end
|
|
}
|
|
|
|
// render li contents
|
|
if has_inside_empty {
|
|
*flags |= MKD_LI_BLOCK
|
|
}
|
|
|
|
workbytes := work.Bytes()
|
|
if *flags&MKD_LI_BLOCK != 0 {
|
|
// intermediate render of block li
|
|
if sublist > 0 && sublist < len(workbytes) {
|
|
parse_block(inter, rndr, workbytes[:sublist])
|
|
parse_block(inter, rndr, workbytes[sublist:])
|
|
} else {
|
|
parse_block(inter, rndr, workbytes)
|
|
}
|
|
} else {
|
|
// intermediate render of inline li
|
|
if sublist > 0 && sublist < len(workbytes) {
|
|
parse_inline(inter, rndr, workbytes[:sublist])
|
|
parse_inline(inter, rndr, workbytes[sublist:])
|
|
} else {
|
|
parse_inline(inter, rndr, workbytes)
|
|
}
|
|
}
|
|
|
|
// render li itself
|
|
if rndr.mk.listitem != nil {
|
|
rndr.mk.listitem(ob, inter.Bytes(), *flags, rndr.mk.opaque)
|
|
}
|
|
|
|
return beg
|
|
}
|
|
|
|
func parse_paragraph(ob *bytes.Buffer, rndr *render, data []byte) int {
|
|
i, end, level := 0, 0, 0
|
|
|
|
for i < len(data) {
|
|
for end = i + 1; end < len(data) && data[end-1] != '\n'; end++ {
|
|
}
|
|
|
|
if is_empty(data[i:]) > 0 {
|
|
break
|
|
}
|
|
if level = is_headerline(data[i:]); level > 0 {
|
|
break
|
|
}
|
|
|
|
if rndr.ext_flags&MKDEXT_LAX_HTML_BLOCKS != 0 {
|
|
if data[i] == '<' && rndr.mk.blockhtml != nil && parse_htmlblock(ob, rndr, data[i:], false) > 0 {
|
|
end = i
|
|
break
|
|
}
|
|
}
|
|
|
|
if is_atxheader(rndr, data[i:]) || is_hrule(data[i:]) {
|
|
end = i
|
|
break
|
|
}
|
|
|
|
i = end
|
|
}
|
|
|
|
work := data
|
|
size := i
|
|
for size > 0 && work[size-1] == '\n' {
|
|
size--
|
|
}
|
|
|
|
if level == 0 {
|
|
tmp := bytes.NewBuffer(nil)
|
|
parse_inline(tmp, rndr, work[:size])
|
|
if rndr.mk.paragraph != nil {
|
|
rndr.mk.paragraph(ob, tmp.Bytes(), rndr.mk.opaque)
|
|
}
|
|
} else {
|
|
if size > 0 {
|
|
beg := 0
|
|
i = size
|
|
size--
|
|
|
|
for size > 0 && work[size] != '\n' {
|
|
size--
|
|
}
|
|
|
|
beg = size + 1
|
|
for size > 0 && work[size-1] == '\n' {
|
|
size--
|
|
}
|
|
|
|
if size > 0 {
|
|
tmp := bytes.NewBuffer(nil)
|
|
parse_inline(tmp, rndr, work[:size])
|
|
if rndr.mk.paragraph != nil {
|
|
rndr.mk.paragraph(ob, tmp.Bytes(), rndr.mk.opaque)
|
|
}
|
|
|
|
work = work[beg:]
|
|
size = i - beg
|
|
} else {
|
|
size = i
|
|
}
|
|
}
|
|
|
|
header_work := bytes.NewBuffer(nil)
|
|
parse_inline(header_work, rndr, work[:size])
|
|
|
|
if rndr.mk.header != nil {
|
|
rndr.mk.header(ob, header_work.Bytes(), level, rndr.mk.opaque)
|
|
}
|
|
}
|
|
|
|
return end
|
|
}
|
|
|
|
|
|
//
|
|
//
|
|
// HTML rendering
|
|
//
|
|
//
|
|
|
|
const (
|
|
HTML_SKIP_HTML = 1 << iota
|
|
HTML_SKIP_STYLE
|
|
HTML_SKIP_IMAGES
|
|
HTML_SKIP_LINKS
|
|
HTML_EXPAND_TABS
|
|
HTML_SAFELINK
|
|
HTML_TOC
|
|
HTML_HARD_WRAP
|
|
HTML_GITHUB_BLOCKCODE
|
|
HTML_USE_XHTML
|
|
)
|
|
|
|
type html_renderopts struct {
|
|
toc_data struct {
|
|
header_count int
|
|
current_level int
|
|
}
|
|
flags uint32
|
|
close_tag string
|
|
}
|
|
|
|
func attr_escape(ob *bytes.Buffer, src []byte) {
|
|
ob.WriteString(html.EscapeString(string(src)))
|
|
}
|
|
|
|
func rndr_header(ob *bytes.Buffer, text []byte, level int, opaque interface{}) {
|
|
options := opaque.(*html_renderopts)
|
|
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
|
|
if options.flags&HTML_TOC != 0 {
|
|
ob.WriteString(fmt.Sprintf("<h%d id=\"toc_%d\">", level, options.toc_data.header_count))
|
|
options.toc_data.header_count++
|
|
} else {
|
|
ob.WriteString(fmt.Sprintf("<h%d>", level))
|
|
}
|
|
|
|
ob.Write(text)
|
|
ob.WriteString(fmt.Sprintf("</h%d>\n", level))
|
|
}
|
|
|
|
func rndr_raw_block(ob *bytes.Buffer, text []byte, opaque interface{}) {
|
|
sz := len(text)
|
|
for sz > 0 && text[sz-1] == '\n' {
|
|
sz--
|
|
}
|
|
org := 0
|
|
for org < sz && text[org] == '\n' {
|
|
org++
|
|
}
|
|
if org >= sz {
|
|
return
|
|
}
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
ob.Write(text[org:sz])
|
|
ob.WriteByte('\n')
|
|
}
|
|
|
|
func rndr_hrule(ob *bytes.Buffer, opaque interface{}) {
|
|
options := opaque.(*html_renderopts)
|
|
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
ob.WriteString("<hr")
|
|
ob.WriteString(options.close_tag)
|
|
}
|
|
|
|
func rndr_blockcode(ob *bytes.Buffer, text []byte, lang string, opaque interface{}) {
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
|
|
if lang != "" {
|
|
ob.WriteString("<pre><code class=\"")
|
|
|
|
for i, cls := 0, 0; i < len(lang); i, cls = i+1, cls+1 {
|
|
for i < len(lang) && unicode.IsSpace(int(lang[i])) {
|
|
i++
|
|
}
|
|
|
|
if i < len(lang) {
|
|
org := i
|
|
for i < len(lang) && !unicode.IsSpace(int(lang[i])) {
|
|
i++
|
|
}
|
|
|
|
if lang[org] == '.' {
|
|
org++
|
|
}
|
|
|
|
if cls > 0 {
|
|
ob.WriteByte(' ')
|
|
}
|
|
attr_escape(ob, []byte(lang[org:]))
|
|
}
|
|
}
|
|
|
|
ob.WriteString("\">")
|
|
} else {
|
|
ob.WriteString("<pre><code>")
|
|
}
|
|
|
|
if len(text) > 0 {
|
|
attr_escape(ob, text)
|
|
}
|
|
|
|
ob.WriteString("</code></pre>\n")
|
|
}
|
|
|
|
func rndr_table(ob *bytes.Buffer, header []byte, body []byte, opaque interface{}) {
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
ob.WriteString("<table><thead>\n")
|
|
ob.Write(header)
|
|
ob.WriteString("\n</thead><tbody>\n")
|
|
ob.Write(body)
|
|
ob.WriteString("\n</tbody></table>")
|
|
}
|
|
|
|
func rndr_tablerow(ob *bytes.Buffer, text []byte, opaque interface{}) {
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
ob.WriteString("<tr>\n")
|
|
ob.Write(text)
|
|
ob.WriteString("\n</tr>")
|
|
}
|
|
|
|
func rndr_tablecell(ob *bytes.Buffer, text []byte, align int, opaque interface{}) {
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
switch align {
|
|
case MKD_TABLE_ALIGN_L:
|
|
ob.WriteString("<td align=\"left\">")
|
|
case MKD_TABLE_ALIGN_R:
|
|
ob.WriteString("<td align=\"right\">")
|
|
case MKD_TABLE_ALIGN_CENTER:
|
|
ob.WriteString("<td align=\"center\">")
|
|
default:
|
|
ob.WriteString("<td>")
|
|
}
|
|
|
|
ob.Write(text)
|
|
ob.WriteString("</td>")
|
|
}
|
|
|
|
func rndr_list(ob *bytes.Buffer, text []byte, flags int, opaque interface{}) {
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
if flags&MKD_LIST_ORDERED != 0 {
|
|
ob.WriteString("<ol>\n")
|
|
} else {
|
|
ob.WriteString("<ul>\n")
|
|
}
|
|
ob.Write(text)
|
|
if flags&MKD_LIST_ORDERED != 0 {
|
|
ob.WriteString("</ol>\n")
|
|
} else {
|
|
ob.WriteString("</ul>\n")
|
|
}
|
|
}
|
|
|
|
func rndr_listitem(ob *bytes.Buffer, text []byte, flags int, opaque interface{}) {
|
|
ob.WriteString("<li>")
|
|
size := len(text)
|
|
for size > 0 && text[size-1] == '\n' {
|
|
size--
|
|
}
|
|
ob.Write(text[:size])
|
|
ob.WriteString("</li>\n")
|
|
}
|
|
|
|
func rndr_paragraph(ob *bytes.Buffer, text []byte, opaque interface{}) {
|
|
options := opaque.(*html_renderopts)
|
|
i := 0
|
|
|
|
if ob.Len() > 0 {
|
|
ob.WriteByte('\n')
|
|
}
|
|
|
|
if len(text) == 0 {
|
|
return
|
|
}
|
|
|
|
for i < len(text) && unicode.IsSpace(int(text[i])) {
|
|
i++
|
|
}
|
|
|
|
if i == len(text) {
|
|
return
|
|
}
|
|
|
|
ob.WriteString("<p>")
|
|
if options.flags&HTML_HARD_WRAP != 0 {
|
|
for i < len(text) {
|
|
org := i
|
|
for i < len(text) && text[i] != '\n' {
|
|
i++
|
|
}
|
|
|
|
if i > org {
|
|
ob.Write(text[org:i])
|
|
}
|
|
|
|
if i >= len(text) {
|
|
break
|
|
}
|
|
|
|
ob.WriteString("<br>")
|
|
ob.WriteString(options.close_tag)
|
|
i++
|
|
}
|
|
} else {
|
|
ob.Write(text[i:])
|
|
}
|
|
ob.WriteString("</p>\n")
|
|
}
|
|
|
|
|
|
func main() {
|
|
ob := bytes.NewBuffer(nil)
|
|
input := ""
|
|
input += "##Header##\n"
|
|
input += "\n"
|
|
input += "----------\n"
|
|
input += "\n"
|
|
input += "Underlined header\n"
|
|
input += "-----------------\n"
|
|
input += "\n"
|
|
input += "<p>Some block html\n"
|
|
input += "</p>\n"
|
|
input += "\n"
|
|
input += "Score | Grade\n"
|
|
input += "------|------\n"
|
|
input += "94 | A\n"
|
|
input += "85 | B\n"
|
|
input += "74 | C\n"
|
|
input += "65 | D\n"
|
|
input += "\n"
|
|
input += "``` go\n"
|
|
input += "func fib(n int) int {\n"
|
|
input += " if n <= 1 {\n"
|
|
input += " return n\n"
|
|
input += " }\n"
|
|
input += " return n * fib(n-1)\n"
|
|
input += "}\n"
|
|
input += "```\n"
|
|
input += "\n"
|
|
input += "> A blockquote\n"
|
|
input += "> or something like that\n"
|
|
input += "> With a table | of two columns\n"
|
|
input += "> -------------|---------------\n"
|
|
input += "> key | value \n"
|
|
input += "\n"
|
|
input += "\n"
|
|
input += "Some **bold** Some *italic* and [a link][1] \n"
|
|
input += "\n"
|
|
input += "A little code sample\n"
|
|
input += "\n"
|
|
input += " </head>\n"
|
|
input += " <title>Web Page Title</title>\n"
|
|
input += " </head>\n"
|
|
input += "\n"
|
|
input += "A picture\n"
|
|
input += "\n"
|
|
input += "![alt text][2]\n"
|
|
input += "\n"
|
|
input += "A list\n"
|
|
input += "\n"
|
|
input += "- apples\n"
|
|
input += "- oranges\n"
|
|
input += "- eggs\n"
|
|
input += "\n"
|
|
input += "A numbered list\n"
|
|
input += "\n"
|
|
input += "1. a\n"
|
|
input += "2. b\n"
|
|
input += "3. c\n"
|
|
input += "\n"
|
|
input += "A little quote\n"
|
|
input += "\n"
|
|
input += "> It is now time for all good men to come to the aid of their country. \n"
|
|
input += "\n"
|
|
input += "A final paragraph.\n"
|
|
input += "\n"
|
|
input += " [1]: http://www.google.com\n"
|
|
input += " [2]: http://www.google.com/intl/en_ALL/images/logo.gif\n"
|
|
|
|
ib := []byte(input)
|
|
rndrer := new(mkd_renderer)
|
|
rndrer.blockcode = rndr_blockcode
|
|
rndrer.blockhtml = rndr_raw_block
|
|
rndrer.header = rndr_header
|
|
rndrer.hrule = rndr_hrule
|
|
rndrer.list = rndr_list
|
|
rndrer.listitem = rndr_listitem
|
|
rndrer.paragraph = rndr_paragraph
|
|
rndrer.table = rndr_table
|
|
rndrer.table_row = rndr_tablerow
|
|
rndrer.table_cell = rndr_tablecell
|
|
rndrer.opaque = &html_renderopts{close_tag: " />"}
|
|
var extensions uint32 = MKDEXT_FENCED_CODE | MKDEXT_TABLES
|
|
Markdown(ob, ib, rndrer, extensions)
|
|
fmt.Print(ob.String())
|
|
}
|
|
|
|
func expand_tabs(ob *bytes.Buffer, line []byte) {
|
|
i, tab := 0, 0
|
|
|
|
for i < len(line) {
|
|
org := i
|
|
for i < len(line) && line[i] != '\t' {
|
|
i++
|
|
tab++
|
|
}
|
|
|
|
if i > org {
|
|
ob.Write(line[org:i])
|
|
}
|
|
|
|
if i >= len(line) {
|
|
break
|
|
}
|
|
|
|
for {
|
|
ob.WriteByte(' ')
|
|
tab++
|
|
if tab%4 == 0 {
|
|
break
|
|
}
|
|
}
|
|
|
|
i++
|
|
}
|
|
}
|
|
|
|
func Markdown(ob *bytes.Buffer, ib []byte, rndrer *mkd_renderer, extensions uint32) {
|
|
// no point in parsing if we can't render
|
|
if rndrer == nil {
|
|
return
|
|
}
|
|
|
|
// fill in the character-level parsers
|
|
markdown_char_ptrs[MD_CHAR_NONE] = nil
|
|
markdown_char_ptrs[MD_CHAR_EMPHASIS] = char_emphasis
|
|
markdown_char_ptrs[MD_CHAR_CODESPAN] = char_codespan
|
|
markdown_char_ptrs[MD_CHAR_LINEBREAK] = char_linebreak
|
|
markdown_char_ptrs[MD_CHAR_LINK] = char_link
|
|
markdown_char_ptrs[MD_CHAR_LANGLE] = char_langle_tag
|
|
markdown_char_ptrs[MD_CHAR_ESCAPE] = char_escape
|
|
markdown_char_ptrs[MD_CHAR_ENTITITY] = char_entity
|
|
markdown_char_ptrs[MD_CHAR_AUTOLINK] = char_autolink
|
|
|
|
// fill in the render structure
|
|
rndr := new(render)
|
|
rndr.mk = rndrer
|
|
rndr.ext_flags = extensions
|
|
rndr.max_nesting = 16
|
|
|
|
if rndr.mk.emphasis != nil || rndr.mk.double_emphasis != nil || rndr.mk.triple_emphasis != nil {
|
|
rndr.active_char['*'] = MD_CHAR_EMPHASIS
|
|
rndr.active_char['_'] = MD_CHAR_EMPHASIS
|
|
if extensions&MKDEXT_STRIKETHROUGH != 0 {
|
|
rndr.active_char['~'] = MD_CHAR_EMPHASIS
|
|
}
|
|
}
|
|
if rndr.mk.codespan != nil {
|
|
rndr.active_char['`'] = MD_CHAR_CODESPAN
|
|
}
|
|
if rndr.mk.linebreak != nil {
|
|
rndr.active_char['\n'] = MD_CHAR_LINEBREAK
|
|
}
|
|
if rndr.mk.image != nil || rndr.mk.link != nil {
|
|
rndr.active_char['['] = MD_CHAR_LINK
|
|
}
|
|
rndr.active_char['<'] = MD_CHAR_LANGLE
|
|
rndr.active_char['\\'] = MD_CHAR_ESCAPE
|
|
rndr.active_char['&'] = MD_CHAR_ENTITITY
|
|
|
|
if extensions&MKDEXT_AUTOLINK != 0 {
|
|
rndr.active_char['h'] = MD_CHAR_AUTOLINK // http, https
|
|
rndr.active_char['H'] = MD_CHAR_AUTOLINK
|
|
|
|
rndr.active_char['f'] = MD_CHAR_AUTOLINK // ftp
|
|
rndr.active_char['F'] = MD_CHAR_AUTOLINK
|
|
|
|
rndr.active_char['m'] = MD_CHAR_AUTOLINK // mailto
|
|
rndr.active_char['M'] = MD_CHAR_AUTOLINK
|
|
}
|
|
|
|
// first pass: look for references, copying everything else
|
|
text := bytes.NewBuffer(nil)
|
|
beg, end := 0, 0
|
|
for beg < len(ib) { // iterate over lines
|
|
if is_ref(ib, beg, &end, rndr) {
|
|
beg = end
|
|
} else { // skip to the next line
|
|
end = beg
|
|
for end < len(ib) && ib[end] != '\n' && ib[end] != '\r' {
|
|
end++
|
|
}
|
|
|
|
// add the line body if present
|
|
if end > beg {
|
|
expand_tabs(text, ib[beg:end])
|
|
}
|
|
|
|
for end < len(ib) && (ib[end] == '\n' || ib[end] == '\r') {
|
|
// add one \n per newline
|
|
if ib[end] == '\n' || (end+1 < len(ib) && ib[end+1] != '\n') {
|
|
text.WriteByte('\n')
|
|
}
|
|
end++
|
|
}
|
|
|
|
beg = end
|
|
}
|
|
}
|
|
|
|
// sort the reference array
|
|
if len(rndr.refs) > 1 {
|
|
sort.Sort(rndr.refs)
|
|
}
|
|
|
|
// second pass: actual rendering
|
|
if rndr.mk.doc_header != nil {
|
|
rndr.mk.doc_header(ob, rndr.mk.opaque)
|
|
}
|
|
|
|
if text.Len() > 0 {
|
|
// add a final newline if not already present
|
|
finalchar := text.Bytes()[text.Len()-1]
|
|
if finalchar != '\n' && finalchar != '\r' {
|
|
text.WriteByte('\n')
|
|
}
|
|
parse_block(ob, rndr, text.Bytes())
|
|
}
|
|
|
|
if rndr.mk.doc_footer != nil {
|
|
rndr.mk.doc_footer(ob, rndr.mk.opaque)
|
|
}
|
|
|
|
if rndr.nesting != 0 {
|
|
panic("Nesting level did not end at zero")
|
|
}
|
|
}
|