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author | Wim <wim@42.be> | 2017-01-17 23:57:47 +0100 |
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committer | Wim <wim@42.be> | 2017-01-18 00:02:37 +0100 |
commit | f8a6e65bfdeb89a7ec340442060c6c053b7d8083 (patch) | |
tree | 8d33c8376c21812e133a497027d9880da07fad25 /vendor/github.com/russross/blackfriday/block.go | |
parent | 6df6c5d615181e91006ac3ceb72a2e09f29d1bb9 (diff) | |
download | matterbridge-msglm-f8a6e65bfdeb89a7ec340442060c6c053b7d8083.tar.gz matterbridge-msglm-f8a6e65bfdeb89a7ec340442060c6c053b7d8083.tar.bz2 matterbridge-msglm-f8a6e65bfdeb89a7ec340442060c6c053b7d8083.zip |
Release v0.9.1v0.9.1
Diffstat (limited to 'vendor/github.com/russross/blackfriday/block.go')
-rw-r--r-- | vendor/github.com/russross/blackfriday/block.go | 1430 |
1 files changed, 1430 insertions, 0 deletions
diff --git a/vendor/github.com/russross/blackfriday/block.go b/vendor/github.com/russross/blackfriday/block.go new file mode 100644 index 00000000..9cf451f0 --- /dev/null +++ b/vendor/github.com/russross/blackfriday/block.go @@ -0,0 +1,1430 @@ +// +// Blackfriday Markdown Processor +// Available at http://github.com/russross/blackfriday +// +// Copyright © 2011 Russ Ross <russ@russross.com>. +// Distributed under the Simplified BSD License. +// See README.md for details. +// + +// +// Functions to parse block-level elements. +// + +package blackfriday + +import ( + "bytes" + + "github.com/shurcooL/sanitized_anchor_name" +) + +// Parse block-level data. +// Note: this function and many that it calls assume that +// the input buffer ends with a newline. +func (p *parser) block(out *bytes.Buffer, data []byte) { + if len(data) == 0 || data[len(data)-1] != '\n' { + panic("block input is missing terminating newline") + } + + // this is called recursively: enforce a maximum depth + if p.nesting >= p.maxNesting { + return + } + p.nesting++ + + // parse out one block-level construct at a time + for len(data) > 0 { + // prefixed header: + // + // # Header 1 + // ## Header 2 + // ... + // ###### Header 6 + if p.isPrefixHeader(data) { + data = data[p.prefixHeader(out, data):] + continue + } + + // block of preformatted HTML: + // + // <div> + // ... + // </div> + if data[0] == '<' { + if i := p.html(out, data, true); i > 0 { + data = data[i:] + continue + } + } + + // title block + // + // % stuff + // % more stuff + // % even more stuff + if p.flags&EXTENSION_TITLEBLOCK != 0 { + if data[0] == '%' { + if i := p.titleBlock(out, data, true); i > 0 { + data = data[i:] + continue + } + } + } + + // blank lines. note: returns the # of bytes to skip + if i := p.isEmpty(data); i > 0 { + data = data[i:] + continue + } + + // indented code block: + // + // func max(a, b int) int { + // if a > b { + // return a + // } + // return b + // } + if p.codePrefix(data) > 0 { + data = data[p.code(out, data):] + continue + } + + // fenced code block: + // + // ``` go + // func fact(n int) int { + // if n <= 1 { + // return n + // } + // return n * fact(n-1) + // } + // ``` + if p.flags&EXTENSION_FENCED_CODE != 0 { + if i := p.fencedCodeBlock(out, data, true); i > 0 { + data = data[i:] + continue + } + } + + // horizontal rule: + // + // ------ + // or + // ****** + // or + // ______ + if p.isHRule(data) { + p.r.HRule(out) + var i int + for i = 0; data[i] != '\n'; i++ { + } + data = data[i:] + continue + } + + // block quote: + // + // > A big quote I found somewhere + // > on the web + if p.quotePrefix(data) > 0 { + data = data[p.quote(out, data):] + continue + } + + // table: + // + // Name | Age | Phone + // ------|-----|--------- + // Bob | 31 | 555-1234 + // Alice | 27 | 555-4321 + if p.flags&EXTENSION_TABLES != 0 { + if i := p.table(out, data); i > 0 { + data = data[i:] + continue + } + } + + // an itemized/unordered list: + // + // * Item 1 + // * Item 2 + // + // also works with + or - + if p.uliPrefix(data) > 0 { + data = data[p.list(out, data, 0):] + continue + } + + // a numbered/ordered list: + // + // 1. Item 1 + // 2. Item 2 + if p.oliPrefix(data) > 0 { + data = data[p.list(out, data, LIST_TYPE_ORDERED):] + continue + } + + // definition lists: + // + // Term 1 + // : Definition a + // : Definition b + // + // Term 2 + // : Definition c + if p.flags&EXTENSION_DEFINITION_LISTS != 0 { + if p.dliPrefix(data) > 0 { + data = data[p.list(out, data, LIST_TYPE_DEFINITION):] + continue + } + } + + // anything else must look like a normal paragraph + // note: this finds underlined headers, too + data = data[p.paragraph(out, data):] + } + + p.nesting-- +} + +func (p *parser) isPrefixHeader(data []byte) bool { + if data[0] != '#' { + return false + } + + if p.flags&EXTENSION_SPACE_HEADERS != 0 { + level := 0 + for level < 6 && data[level] == '#' { + level++ + } + if data[level] != ' ' { + return false + } + } + return true +} + +func (p *parser) prefixHeader(out *bytes.Buffer, data []byte) int { + level := 0 + for level < 6 && data[level] == '#' { + level++ + } + i := skipChar(data, level, ' ') + end := skipUntilChar(data, i, '\n') + skip := end + id := "" + if p.flags&EXTENSION_HEADER_IDS != 0 { + j, k := 0, 0 + // find start/end of header id + for j = i; j < end-1 && (data[j] != '{' || data[j+1] != '#'); j++ { + } + for k = j + 1; k < end && data[k] != '}'; k++ { + } + // extract header id iff found + if j < end && k < end { + id = string(data[j+2 : k]) + end = j + skip = k + 1 + for end > 0 && data[end-1] == ' ' { + end-- + } + } + } + for end > 0 && data[end-1] == '#' { + if isBackslashEscaped(data, end-1) { + break + } + end-- + } + for end > 0 && data[end-1] == ' ' { + end-- + } + if end > i { + if id == "" && p.flags&EXTENSION_AUTO_HEADER_IDS != 0 { + id = sanitized_anchor_name.Create(string(data[i:end])) + } + work := func() bool { + p.inline(out, data[i:end]) + return true + } + p.r.Header(out, work, level, id) + } + return skip +} + +func (p *parser) isUnderlinedHeader(data []byte) int { + // test of level 1 header + if data[0] == '=' { + i := skipChar(data, 1, '=') + i = skipChar(data, i, ' ') + if data[i] == '\n' { + return 1 + } else { + return 0 + } + } + + // test of level 2 header + if data[0] == '-' { + i := skipChar(data, 1, '-') + i = skipChar(data, i, ' ') + if data[i] == '\n' { + return 2 + } else { + return 0 + } + } + + return 0 +} + +func (p *parser) titleBlock(out *bytes.Buffer, data []byte, doRender bool) int { + if data[0] != '%' { + return 0 + } + splitData := bytes.Split(data, []byte("\n")) + var i int + for idx, b := range splitData { + if !bytes.HasPrefix(b, []byte("%")) { + i = idx // - 1 + break + } + } + + data = bytes.Join(splitData[0:i], []byte("\n")) + p.r.TitleBlock(out, data) + + return len(data) +} + +func (p *parser) html(out *bytes.Buffer, data []byte, doRender bool) int { + var i, j int + + // identify the opening tag + if data[0] != '<' { + return 0 + } + curtag, tagfound := p.htmlFindTag(data[1:]) + + // handle special cases + if !tagfound { + // check for an HTML comment + if size := p.htmlComment(out, data, doRender); size > 0 { + return size + } + + // check for an <hr> tag + if size := p.htmlHr(out, data, doRender); size > 0 { + return size + } + + // check for HTML CDATA + if size := p.htmlCDATA(out, data, doRender); size > 0 { + return size + } + + // no special case recognized + return 0 + } + + // look for an unindented matching closing tag + // followed by a blank line + found := false + /* + closetag := []byte("\n</" + curtag + ">") + j = len(curtag) + 1 + for !found { + // scan for a closing tag at the beginning of a line + if skip := bytes.Index(data[j:], closetag); skip >= 0 { + j += skip + len(closetag) + } else { + break + } + + // see if it is the only thing on the line + if skip := p.isEmpty(data[j:]); skip > 0 { + // see if it is followed by a blank line/eof + j += skip + if j >= len(data) { + found = true + i = j + } else { + if skip := p.isEmpty(data[j:]); skip > 0 { + j += skip + found = true + i = j + } + } + } + } + */ + + // if not found, try a second pass looking for indented match + // but not if tag is "ins" or "del" (following original Markdown.pl) + if !found && 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 = p.htmlFindEnd(curtag, 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 doRender { + // trim newlines + end := i + for end > 0 && data[end-1] == '\n' { + end-- + } + p.r.BlockHtml(out, data[:end]) + } + + return i +} + +func (p *parser) renderHTMLBlock(out *bytes.Buffer, data []byte, start int, doRender bool) int { + // html block needs to end with a blank line + if i := p.isEmpty(data[start:]); i > 0 { + size := start + i + if doRender { + // trim trailing newlines + end := size + for end > 0 && data[end-1] == '\n' { + end-- + } + p.r.BlockHtml(out, data[:end]) + } + return size + } + return 0 +} + +// HTML comment, lax form +func (p *parser) htmlComment(out *bytes.Buffer, data []byte, doRender bool) int { + i := p.inlineHTMLComment(out, data) + return p.renderHTMLBlock(out, data, i, doRender) +} + +// HTML CDATA section +func (p *parser) htmlCDATA(out *bytes.Buffer, data []byte, doRender bool) int { + const cdataTag = "<![cdata[" + const cdataTagLen = len(cdataTag) + if len(data) < cdataTagLen+1 { + return 0 + } + if !bytes.Equal(bytes.ToLower(data[:cdataTagLen]), []byte(cdataTag)) { + return 0 + } + i := cdataTagLen + // scan for an end-of-comment marker, across lines if necessary + for i < len(data) && !(data[i-2] == ']' && data[i-1] == ']' && data[i] == '>') { + i++ + } + i++ + // no end-of-comment marker + if i >= len(data) { + return 0 + } + return p.renderHTMLBlock(out, data, i, doRender) +} + +// HR, which is the only self-closing block tag considered +func (p *parser) htmlHr(out *bytes.Buffer, data []byte, doRender bool) int { + if data[0] != '<' || (data[1] != 'h' && data[1] != 'H') || (data[2] != 'r' && data[2] != 'R') { + return 0 + } + if data[3] != ' ' && data[3] != '/' && data[3] != '>' { + // not an <hr> tag after all; at least not a valid one + return 0 + } + + i := 3 + for data[i] != '>' && data[i] != '\n' { + i++ + } + + if data[i] == '>' { + return p.renderHTMLBlock(out, data, i+1, doRender) + } + + return 0 +} + +func (p *parser) htmlFindTag(data []byte) (string, bool) { + i := 0 + for isalnum(data[i]) { + i++ + } + key := string(data[:i]) + if _, ok := blockTags[key]; ok { + return key, true + } + return "", false +} + +func (p *parser) htmlFindEnd(tag string, data []byte) int { + // assume data[0] == '<' && data[1] == '/' already tested + + // check if tag is a match + closetag := []byte("</" + tag + ">") + if !bytes.HasPrefix(data, closetag) { + return 0 + } + i := len(closetag) + + // check that the rest of the line is blank + skip := 0 + if skip = p.isEmpty(data[i:]); skip == 0 { + return 0 + } + i += skip + skip = 0 + + if i >= len(data) { + return i + } + + if p.flags&EXTENSION_LAX_HTML_BLOCKS != 0 { + return i + } + if skip = p.isEmpty(data[i:]); skip == 0 { + // following line must be blank + return 0 + } + + return i + skip +} + +func (*parser) isEmpty(data []byte) int { + // it is okay to call isEmpty on an empty buffer + if len(data) == 0 { + return 0 + } + + 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 (*parser) isHRule(data []byte) bool { + i := 0 + + // skip up to three spaces + for i < 3 && data[i] == ' ' { + i++ + } + + // look at the hrule char + if data[i] != '*' && data[i] != '-' && data[i] != '_' { + return false + } + c := data[i] + + // the whole line must be the char or whitespace + n := 0 + for data[i] != '\n' { + switch { + case data[i] == c: + n++ + case data[i] != ' ': + return false + } + i++ + } + + return n >= 3 +} + +// isFenceLine checks if there's a fence line (e.g., ``` or ``` go) at the beginning of data, +// and returns the end index if so, or 0 otherwise. It also returns the marker found. +// If syntax is not nil, it gets set to the syntax specified in the fence line. +// A final newline is mandatory to recognize the fence line, unless newlineOptional is true. +func isFenceLine(data []byte, syntax *string, oldmarker string, newlineOptional bool) (end int, marker string) { + i, size := 0, 0 + + // skip up to three spaces + for i < len(data) && i < 3 && data[i] == ' ' { + i++ + } + + // check for the marker characters: ~ or ` + if i >= len(data) { + return 0, "" + } + if data[i] != '~' && data[i] != '`' { + return 0, "" + } + + c := data[i] + + // the whole line must be the same char or whitespace + for i < len(data) && data[i] == c { + size++ + i++ + } + + // the marker char must occur at least 3 times + if size < 3 { + return 0, "" + } + marker = string(data[i-size : i]) + + // if this is the end marker, it must match the beginning marker + if oldmarker != "" && marker != oldmarker { + return 0, "" + } + + // TODO(shurcooL): It's probably a good idea to simplify the 2 code paths here + // into one, always get the syntax, and discard it if the caller doesn't care. + if syntax != nil { + syn := 0 + i = skipChar(data, i, ' ') + + if i >= len(data) { + if newlineOptional && i == len(data) { + return i, marker + } + return 0, "" + } + + syntaxStart := i + + if data[i] == '{' { + i++ + syntaxStart++ + + for i < len(data) && data[i] != '}' && data[i] != '\n' { + syn++ + i++ + } + + if i >= len(data) || data[i] != '}' { + return 0, "" + } + + // strip all whitespace at the beginning and the end + // of the {} block + for syn > 0 && isspace(data[syntaxStart]) { + syntaxStart++ + syn-- + } + + for syn > 0 && isspace(data[syntaxStart+syn-1]) { + syn-- + } + + i++ + } else { + for i < len(data) && !isspace(data[i]) { + syn++ + i++ + } + } + + *syntax = string(data[syntaxStart : syntaxStart+syn]) + } + + i = skipChar(data, i, ' ') + if i >= len(data) || data[i] != '\n' { + if newlineOptional && i == len(data) { + return i, marker + } + return 0, "" + } + + return i + 1, marker // Take newline into account. +} + +// fencedCodeBlock returns the end index if data contains a fenced code block at the beginning, +// or 0 otherwise. It writes to out if doRender is true, otherwise it has no side effects. +// If doRender is true, a final newline is mandatory to recognize the fenced code block. +func (p *parser) fencedCodeBlock(out *bytes.Buffer, data []byte, doRender bool) int { + var syntax string + beg, marker := isFenceLine(data, &syntax, "", false) + if beg == 0 || beg >= len(data) { + return 0 + } + + var work bytes.Buffer + + for { + // safe to assume beg < len(data) + + // check for the end of the code block + newlineOptional := !doRender + fenceEnd, _ := isFenceLine(data[beg:], nil, marker, newlineOptional) + if fenceEnd != 0 { + beg += fenceEnd + break + } + + // copy the current line + end := skipUntilChar(data, beg, '\n') + 1 + + // did we reach the end of the buffer without a closing marker? + if end >= len(data) { + return 0 + } + + // verbatim copy to the working buffer + if doRender { + work.Write(data[beg:end]) + } + beg = end + } + + if doRender { + p.r.BlockCode(out, work.Bytes(), syntax) + } + + return beg +} + +func (p *parser) table(out *bytes.Buffer, data []byte) int { + var header bytes.Buffer + i, columns := p.tableHeader(&header, data) + if i == 0 { + return 0 + } + + var body bytes.Buffer + + for i < len(data) { + pipes, rowStart := 0, i + for ; data[i] != '\n'; i++ { + if data[i] == '|' { + pipes++ + } + } + + if pipes == 0 { + i = rowStart + break + } + + // include the newline in data sent to tableRow + i++ + p.tableRow(&body, data[rowStart:i], columns, false) + } + + p.r.Table(out, header.Bytes(), body.Bytes(), columns) + + return i +} + +// check if the specified position is preceded by an odd number of backslashes +func isBackslashEscaped(data []byte, i int) bool { + backslashes := 0 + for i-backslashes-1 >= 0 && data[i-backslashes-1] == '\\' { + backslashes++ + } + return backslashes&1 == 1 +} + +func (p *parser) tableHeader(out *bytes.Buffer, data []byte) (size int, columns []int) { + i := 0 + colCount := 1 + for i = 0; data[i] != '\n'; i++ { + if data[i] == '|' && !isBackslashEscaped(data, i) { + colCount++ + } + } + + // doesn't look like a table header + if colCount == 1 { + return + } + + // include the newline in the data sent to tableRow + header := data[:i+1] + + // column count ignores pipes at beginning or end of line + if data[0] == '|' { + colCount-- + } + if i > 2 && data[i-1] == '|' && !isBackslashEscaped(data, i-1) { + colCount-- + } + + columns = make([]int, colCount) + + // move on to the header underline + i++ + if i >= len(data) { + return + } + + if data[i] == '|' && !isBackslashEscaped(data, i) { + i++ + } + i = skipChar(data, i, ' ') + + // each column header is of form: / *:?-+:? *|/ with # dashes + # colons >= 3 + // and trailing | optional on last column + col := 0 + for data[i] != '\n' { + dashes := 0 + + if data[i] == ':' { + i++ + columns[col] |= TABLE_ALIGNMENT_LEFT + dashes++ + } + for data[i] == '-' { + i++ + dashes++ + } + if data[i] == ':' { + i++ + columns[col] |= TABLE_ALIGNMENT_RIGHT + dashes++ + } + for data[i] == ' ' { + i++ + } + + // end of column test is messy + switch { + case dashes < 3: + // not a valid column + return + + case data[i] == '|' && !isBackslashEscaped(data, i): + // marker found, now skip past trailing whitespace + col++ + i++ + for data[i] == ' ' { + i++ + } + + // trailing junk found after last column + if col >= colCount && data[i] != '\n' { + return + } + + case (data[i] != '|' || isBackslashEscaped(data, i)) && col+1 < colCount: + // something else found where marker was required + return + + case data[i] == '\n': + // marker is optional for the last column + col++ + + default: + // trailing junk found after last column + return + } + } + if col != colCount { + return + } + + p.tableRow(out, header, columns, true) + size = i + 1 + return +} + +func (p *parser) tableRow(out *bytes.Buffer, data []byte, columns []int, header bool) { + i, col := 0, 0 + var rowWork bytes.Buffer + + if data[i] == '|' && !isBackslashEscaped(data, i) { + i++ + } + + for col = 0; col < len(columns) && i < len(data); col++ { + for data[i] == ' ' { + i++ + } + + cellStart := i + + for (data[i] != '|' || isBackslashEscaped(data, i)) && data[i] != '\n' { + i++ + } + + cellEnd := i + + // skip the end-of-cell marker, possibly taking us past end of buffer + i++ + + for cellEnd > cellStart && data[cellEnd-1] == ' ' { + cellEnd-- + } + + var cellWork bytes.Buffer + p.inline(&cellWork, data[cellStart:cellEnd]) + + if header { + p.r.TableHeaderCell(&rowWork, cellWork.Bytes(), columns[col]) + } else { + p.r.TableCell(&rowWork, cellWork.Bytes(), columns[col]) + } + } + + // pad it out with empty columns to get the right number + for ; col < len(columns); col++ { + if header { + p.r.TableHeaderCell(&rowWork, nil, columns[col]) + } else { + p.r.TableCell(&rowWork, nil, columns[col]) + } + } + + // silently ignore rows with too many cells + + p.r.TableRow(out, rowWork.Bytes()) +} + +// returns blockquote prefix length +func (p *parser) quotePrefix(data []byte) int { + i := 0 + for i < 3 && data[i] == ' ' { + i++ + } + if data[i] == '>' { + if data[i+1] == ' ' { + return i + 2 + } + return i + 1 + } + return 0 +} + +// blockquote ends with at least one blank line +// followed by something without a blockquote prefix +func (p *parser) terminateBlockquote(data []byte, beg, end int) bool { + if p.isEmpty(data[beg:]) <= 0 { + return false + } + if end >= len(data) { + return true + } + return p.quotePrefix(data[end:]) == 0 && p.isEmpty(data[end:]) == 0 +} + +// parse a blockquote fragment +func (p *parser) quote(out *bytes.Buffer, data []byte) int { + var raw bytes.Buffer + beg, end := 0, 0 + for beg < len(data) { + end = beg + // Step over whole lines, collecting them. While doing that, check for + // fenced code and if one's found, incorporate it altogether, + // irregardless of any contents inside it + for data[end] != '\n' { + if p.flags&EXTENSION_FENCED_CODE != 0 { + if i := p.fencedCodeBlock(out, data[end:], false); i > 0 { + // -1 to compensate for the extra end++ after the loop: + end += i - 1 + break + } + } + end++ + } + end++ + + if pre := p.quotePrefix(data[beg:]); pre > 0 { + // skip the prefix + beg += pre + } else if p.terminateBlockquote(data, beg, end) { + break + } + + // this line is part of the blockquote + raw.Write(data[beg:end]) + beg = end + } + + var cooked bytes.Buffer + p.block(&cooked, raw.Bytes()) + p.r.BlockQuote(out, cooked.Bytes()) + return end +} + +// returns prefix length for block code +func (p *parser) codePrefix(data []byte) int { + if data[0] == ' ' && data[1] == ' ' && data[2] == ' ' && data[3] == ' ' { + return 4 + } + return 0 +} + +func (p *parser) code(out *bytes.Buffer, data []byte) int { + var work bytes.Buffer + + i := 0 + for i < len(data) { + beg := i + for data[i] != '\n' { + i++ + } + i++ + + blankline := p.isEmpty(data[beg:i]) > 0 + if pre := p.codePrefix(data[beg:i]); pre > 0 { + beg += pre + } else if !blankline { + // non-empty, non-prefixed line breaks the pre + i = beg + break + } + + // verbatim copy to the working buffeu + if blankline { + work.WriteByte('\n') + } else { + work.Write(data[beg:i]) + } + } + + // trim all the \n off the end of work + workbytes := work.Bytes() + eol := len(workbytes) + for eol > 0 && workbytes[eol-1] == '\n' { + eol-- + } + if eol != len(workbytes) { + work.Truncate(eol) + } + + work.WriteByte('\n') + + p.r.BlockCode(out, work.Bytes(), "") + + return i +} + +// returns unordered list item prefix +func (p *parser) uliPrefix(data []byte) int { + i := 0 + + // start with up to 3 spaces + for i < 3 && data[i] == ' ' { + i++ + } + + // need a *, +, or - followed by a space + if (data[i] != '*' && data[i] != '+' && data[i] != '-') || + data[i+1] != ' ' { + return 0 + } + return i + 2 +} + +// returns ordered list item prefix +func (p *parser) oliPrefix(data []byte) int { + i := 0 + + // start with up to 3 spaces + for i < 3 && data[i] == ' ' { + i++ + } + + // count the digits + start := i + for data[i] >= '0' && data[i] <= '9' { + i++ + } + + // we need >= 1 digits followed by a dot and a space + if start == i || data[i] != '.' || data[i+1] != ' ' { + return 0 + } + return i + 2 +} + +// returns definition list item prefix +func (p *parser) dliPrefix(data []byte) int { + i := 0 + + // need a : followed by a spaces + if data[i] != ':' || data[i+1] != ' ' { + return 0 + } + for data[i] == ' ' { + i++ + } + return i + 2 +} + +// parse ordered or unordered list block +func (p *parser) list(out *bytes.Buffer, data []byte, flags int) int { + i := 0 + flags |= LIST_ITEM_BEGINNING_OF_LIST + work := func() bool { + for i < len(data) { + skip := p.listItem(out, data[i:], &flags) + i += skip + + if skip == 0 || flags&LIST_ITEM_END_OF_LIST != 0 { + break + } + flags &= ^LIST_ITEM_BEGINNING_OF_LIST + } + return true + } + + p.r.List(out, work, flags) + return i +} + +// Parse a single list item. +// Assumes initial prefix is already removed if this is a sublist. +func (p *parser) listItem(out *bytes.Buffer, data []byte, flags *int) int { + // keep track of the indentation of the first line + itemIndent := 0 + for itemIndent < 3 && data[itemIndent] == ' ' { + itemIndent++ + } + + i := p.uliPrefix(data) + if i == 0 { + i = p.oliPrefix(data) + } + if i == 0 { + i = p.dliPrefix(data) + // reset definition term flag + if i > 0 { + *flags &= ^LIST_TYPE_TERM + } + } + if i == 0 { + // if in defnition list, set term flag and continue + if *flags&LIST_TYPE_DEFINITION != 0 { + *flags |= LIST_TYPE_TERM + } else { + return 0 + } + } + + // skip leading whitespace on first line + for data[i] == ' ' { + i++ + } + + // find the end of the line + line := i + for i > 0 && data[i-1] != '\n' { + i++ + } + + // get working buffer + var raw bytes.Buffer + + // put the first line into the working buffer + raw.Write(data[line:i]) + line = i + + // process the following lines + containsBlankLine := false + sublist := 0 + +gatherlines: + for line < len(data) { + i++ + + // find the end of this line + for data[i-1] != '\n' { + i++ + } + + // if it is an empty line, guess that it is part of this item + // and move on to the next line + if p.isEmpty(data[line:i]) > 0 { + containsBlankLine = true + raw.Write(data[line:i]) + line = i + continue + } + + // calculate the indentation + indent := 0 + for indent < 4 && line+indent < i && data[line+indent] == ' ' { + indent++ + } + + chunk := data[line+indent : i] + + // evaluate how this line fits in + switch { + // is this a nested list item? + case (p.uliPrefix(chunk) > 0 && !p.isHRule(chunk)) || + p.oliPrefix(chunk) > 0 || + p.dliPrefix(chunk) > 0: + + if containsBlankLine { + // end the list if the type changed after a blank line + if indent <= itemIndent && + ((*flags&LIST_TYPE_ORDERED != 0 && p.uliPrefix(chunk) > 0) || + (*flags&LIST_TYPE_ORDERED == 0 && p.oliPrefix(chunk) > 0)) { + + *flags |= LIST_ITEM_END_OF_LIST + break gatherlines + } + *flags |= LIST_ITEM_CONTAINS_BLOCK + } + + // to be a nested list, it must be indented more + // if not, it is the next item in the same list + if indent <= itemIndent { + break gatherlines + } + + // is this the first item in the nested list? + if sublist == 0 { + sublist = raw.Len() + } + + // is this a nested prefix header? + case p.isPrefixHeader(chunk): + // if the header is not indented, it is not nested in the list + // and thus ends the list + if containsBlankLine && indent < 4 { + *flags |= LIST_ITEM_END_OF_LIST + break gatherlines + } + *flags |= LIST_ITEM_CONTAINS_BLOCK + + // anything following an empty line is only part + // of this item if it is indented 4 spaces + // (regardless of the indentation of the beginning of the item) + case containsBlankLine && indent < 4: + if *flags&LIST_TYPE_DEFINITION != 0 && i < len(data)-1 { + // is the next item still a part of this list? + next := i + for data[next] != '\n' { + next++ + } + for next < len(data)-1 && data[next] == '\n' { + next++ + } + if i < len(data)-1 && data[i] != ':' && data[next] != ':' { + *flags |= LIST_ITEM_END_OF_LIST + } + } else { + *flags |= LIST_ITEM_END_OF_LIST + } + break gatherlines + + // a blank line means this should be parsed as a block + case containsBlankLine: + *flags |= LIST_ITEM_CONTAINS_BLOCK + } + + containsBlankLine = false + + // add the line into the working buffer without prefix + raw.Write(data[line+indent : i]) + + line = i + } + + // If reached end of data, the Renderer.ListItem call we're going to make below + // is definitely the last in the list. + if line >= len(data) { + *flags |= LIST_ITEM_END_OF_LIST + } + + rawBytes := raw.Bytes() + + // render the contents of the list item + var cooked bytes.Buffer + if *flags&LIST_ITEM_CONTAINS_BLOCK != 0 && *flags&LIST_TYPE_TERM == 0 { + // intermediate render of block item, except for definition term + if sublist > 0 { + p.block(&cooked, rawBytes[:sublist]) + p.block(&cooked, rawBytes[sublist:]) + } else { + p.block(&cooked, rawBytes) + } + } else { + // intermediate render of inline item + if sublist > 0 { + p.inline(&cooked, rawBytes[:sublist]) + p.block(&cooked, rawBytes[sublist:]) + } else { + p.inline(&cooked, rawBytes) + } + } + + // render the actual list item + cookedBytes := cooked.Bytes() + parsedEnd := len(cookedBytes) + + // strip trailing newlines + for parsedEnd > 0 && cookedBytes[parsedEnd-1] == '\n' { + parsedEnd-- + } + p.r.ListItem(out, cookedBytes[:parsedEnd], *flags) + + return line +} + +// render a single paragraph that has already been parsed out +func (p *parser) renderParagraph(out *bytes.Buffer, data []byte) { + if len(data) == 0 { + return + } + + // trim leading spaces + beg := 0 + for data[beg] == ' ' { + beg++ + } + + // trim trailing newline + end := len(data) - 1 + + // trim trailing spaces + for end > beg && data[end-1] == ' ' { + end-- + } + + work := func() bool { + p.inline(out, data[beg:end]) + return true + } + p.r.Paragraph(out, work) +} + +func (p *parser) paragraph(out *bytes.Buffer, data []byte) int { + // prev: index of 1st char of previous line + // line: index of 1st char of current line + // i: index of cursor/end of current line + var prev, line, i int + + // keep going until we find something to mark the end of the paragraph + for i < len(data) { + // mark the beginning of the current line + prev = line + current := data[i:] + line = i + + // did we find a blank line marking the end of the paragraph? + if n := p.isEmpty(current); n > 0 { + // did this blank line followed by a definition list item? + if p.flags&EXTENSION_DEFINITION_LISTS != 0 { + if i < len(data)-1 && data[i+1] == ':' { + return p.list(out, data[prev:], LIST_TYPE_DEFINITION) + } + } + + p.renderParagraph(out, data[:i]) + return i + n + } + + // an underline under some text marks a header, so our paragraph ended on prev line + if i > 0 { + if level := p.isUnderlinedHeader(current); level > 0 { + // render the paragraph + p.renderParagraph(out, data[:prev]) + + // ignore leading and trailing whitespace + eol := i - 1 + for prev < eol && data[prev] == ' ' { + prev++ + } + for eol > prev && data[eol-1] == ' ' { + eol-- + } + + // render the header + // this ugly double closure avoids forcing variables onto the heap + work := func(o *bytes.Buffer, pp *parser, d []byte) func() bool { + return func() bool { + pp.inline(o, d) + return true + } + }(out, p, data[prev:eol]) + + id := "" + if p.flags&EXTENSION_AUTO_HEADER_IDS != 0 { + id = sanitized_anchor_name.Create(string(data[prev:eol])) + } + + p.r.Header(out, work, level, id) + + // find the end of the underline + for data[i] != '\n' { + i++ + } + return i + } + } + + // if the next line starts a block of HTML, then the paragraph ends here + if p.flags&EXTENSION_LAX_HTML_BLOCKS != 0 { + if data[i] == '<' && p.html(out, current, false) > 0 { + // rewind to before the HTML block + p.renderParagraph(out, data[:i]) + return i + } + } + + // if there's a prefixed header or a horizontal rule after this, paragraph is over + if p.isPrefixHeader(current) || p.isHRule(current) { + p.renderParagraph(out, data[:i]) + return i + } + + // if there's a fenced code block, paragraph is over + if p.flags&EXTENSION_FENCED_CODE != 0 { + if p.fencedCodeBlock(out, current, false) > 0 { + p.renderParagraph(out, data[:i]) + return i + } + } + + // if there's a definition list item, prev line is a definition term + if p.flags&EXTENSION_DEFINITION_LISTS != 0 { + if p.dliPrefix(current) != 0 { + return p.list(out, data[prev:], LIST_TYPE_DEFINITION) + } + } + + // if there's a list after this, paragraph is over + if p.flags&EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK != 0 { + if p.uliPrefix(current) != 0 || + p.oliPrefix(current) != 0 || + p.quotePrefix(current) != 0 || + p.codePrefix(current) != 0 { + p.renderParagraph(out, data[:i]) + return i + } + } + + // otherwise, scan to the beginning of the next line + for data[i] != '\n' { + i++ + } + i++ + } + + p.renderParagraph(out, data[:i]) + return i +} |