move some code to parser.go
This commit is contained in:
Krzysztof Kowalczyk
parent
1e4781ae5c
commit
ce3ef7474d
45
block.go
45
block.go
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@ -28,6 +28,51 @@ const (
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var (
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reBackslashOrAmp = regexp.MustCompile("[\\&]")
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reEntityOrEscapedChar = regexp.MustCompile("(?i)\\\\" + escapable + "|" + charEntity)
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// blockTags is a set of tags that are recognized as HTML block tags.
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// Any of these can be included in markdown text without special escaping.
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blockTags = map[string]struct{}{
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"blockquote": struct{}{},
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"del": struct{}{},
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"div": struct{}{},
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"dl": struct{}{},
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"fieldset": struct{}{},
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"form": struct{}{},
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"h1": struct{}{},
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"h2": struct{}{},
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"h3": struct{}{},
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"h4": struct{}{},
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"h5": struct{}{},
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"h6": struct{}{},
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"iframe": struct{}{},
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"ins": struct{}{},
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"math": struct{}{},
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"noscript": struct{}{},
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"ol": struct{}{},
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"pre": struct{}{},
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"p": struct{}{},
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"script": struct{}{},
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"style": struct{}{},
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"table": struct{}{},
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"ul": struct{}{},
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// HTML5
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"address": struct{}{},
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"article": struct{}{},
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"aside": struct{}{},
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"canvas": struct{}{},
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"figcaption": struct{}{},
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"figure": struct{}{},
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"footer": struct{}{},
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"header": struct{}{},
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"hgroup": struct{}{},
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"main": struct{}{},
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"nav": struct{}{},
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"output": struct{}{},
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"progress": struct{}{},
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"section": struct{}{},
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"video": struct{}{},
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}
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)
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// SanitizeAnchorName returns a sanitized anchor name for the given text.
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836
markdown.go
836
markdown.go
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@ -8,125 +8,13 @@
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package markdown
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import (
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"bytes"
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"fmt"
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"io"
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"strings"
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"unicode/utf8"
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)
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// Version string of the package. Appears in the rendered document when
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// CompletePage flag is on.
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const Version = "2.0"
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// Extensions is a bitmask of enabled Parser extensions.
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type Extensions int
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// Bit flags representing markdown parsing extensions.
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// Use | (or) to specify multiple extensions.
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const (
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NoExtensions Extensions = 0
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NoIntraEmphasis Extensions = 1 << iota // Ignore emphasis markers inside words
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Tables // Render tables
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FencedCode // Render fenced code blocks
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Autolink // Detect embedded URLs that are not explicitly marked
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Strikethrough // Strikethrough text using ~~test~~
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LaxHTMLBlocks // Loosen up HTML block parsing rules
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SpaceHeadings // Be strict about prefix heading rules
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HardLineBreak // Translate newlines into line breaks
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TabSizeEight // Expand tabs to eight spaces instead of four
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Footnotes // Pandoc-style footnotes
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NoEmptyLineBeforeBlock // No need to insert an empty line to start a (code, quote, ordered list, unordered list) block
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HeadingIDs // specify heading IDs with {#id}
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Titleblock // Titleblock ala pandoc
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AutoHeadingIDs // Create the heading ID from the text
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BackslashLineBreak // Translate trailing backslashes into line breaks
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DefinitionLists // Render definition lists
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CommonExtensions Extensions = NoIntraEmphasis | Tables | FencedCode |
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Autolink | Strikethrough | SpaceHeadings | HeadingIDs |
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BackslashLineBreak | DefinitionLists
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)
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// ListType contains bitwise or'ed flags for list and list item objects.
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type ListType int
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// These are the possible flag values for the ListItem renderer.
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// Multiple flag values may be ORed together.
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// These are mostly of interest if you are writing a new output format.
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const (
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ListTypeOrdered ListType = 1 << iota
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ListTypeDefinition
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ListTypeTerm
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ListItemContainsBlock
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ListItemBeginningOfList // TODO: figure out if this is of any use now
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ListItemEndOfList
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)
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// CellAlignFlags holds a type of alignment in a table cell.
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type CellAlignFlags int
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// These are the possible flag values for the table cell renderer.
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// Only a single one of these values will be used; they are not ORed together.
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// These are mostly of interest if you are writing a new output format.
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const (
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TableAlignmentLeft CellAlignFlags = 1 << iota
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TableAlignmentRight
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TableAlignmentCenter = (TableAlignmentLeft | TableAlignmentRight)
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)
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// The size of a tab stop.
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const (
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TabSizeDefault = 4
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TabSizeDouble = 8
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)
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// blockTags is a set of tags that are recognized as HTML block tags.
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// Any of these can be included in markdown text without special escaping.
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var blockTags = map[string]struct{}{
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"blockquote": struct{}{},
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"del": struct{}{},
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"div": struct{}{},
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"dl": struct{}{},
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"fieldset": struct{}{},
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"form": struct{}{},
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"h1": struct{}{},
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"h2": struct{}{},
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"h3": struct{}{},
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"h4": struct{}{},
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"h5": struct{}{},
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"h6": struct{}{},
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"iframe": struct{}{},
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"ins": struct{}{},
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"math": struct{}{},
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"noscript": struct{}{},
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"ol": struct{}{},
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"pre": struct{}{},
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"p": struct{}{},
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"script": struct{}{},
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"style": struct{}{},
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"table": struct{}{},
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"ul": struct{}{},
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// HTML5
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"address": struct{}{},
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"article": struct{}{},
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"aside": struct{}{},
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"canvas": struct{}{},
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"figcaption": struct{}{},
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"figure": struct{}{},
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"footer": struct{}{},
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"header": struct{}{},
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"hgroup": struct{}{},
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"main": struct{}{},
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"nav": struct{}{},
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"output": struct{}{},
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"progress": struct{}{},
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"section": struct{}{},
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"video": struct{}{},
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}
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// Renderer is the rendering interface. This is mostly of interest if you are
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// implementing a new rendering format.
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//
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@ -156,169 +44,6 @@ type Renderer interface {
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RenderFooter(w io.Writer, ast *Node)
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}
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// Callback functions for inline parsing. One such function is defined
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// for each character that triggers a response when parsing inline data.
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type inlineParser func(p *Parser, data []byte, offset int) (int, *Node)
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// ReferenceOverrideFunc is expected to be called with a reference string and
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// return either a valid Reference type that the reference string maps to or
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// nil. If overridden is false, the default reference logic will be executed.
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// See the documentation in Options for more details on use-case.
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type ReferenceOverrideFunc func(reference string) (ref *Reference, overridden bool)
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// Parser is a type that holds extensions and the runtime state used by
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// Parse, and the renderer. You can not use it directly, construct it with New.
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type Parser struct {
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// ReferenceOverride is an optional function callback that is called every
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// time a reference is resolved. It can be set before starting parsing.
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//
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// In Markdown, the link reference syntax can be made to resolve a link to
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// a reference instead of an inline URL, in one of the following ways:
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//
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// * [link text][refid]
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// * [refid][]
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//
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// Usually, the refid is defined at the bottom of the Markdown document. If
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// this override function is provided, the refid is passed to the override
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// function first, before consulting the defined refids at the bottom. If
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// the override function indicates an override did not occur, the refids at
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// the bottom will be used to fill in the link details.
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ReferenceOverride ReferenceOverrideFunc
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// after parsing, this is root of parsed ast
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Doc *Node
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extensions Extensions
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refs map[string]*reference
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inlineCallback [256]inlineParser
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nesting int
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maxNesting int
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insideLink bool
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// Footnotes need to be ordered as well as available to quickly check for
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// presence. If a ref is also a footnote, it's stored both in refs and here
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// in notes. Slice is nil if footnotes not enabled.
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notes []*reference
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tip *Node // = doc
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oldTip *Node
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lastMatchedContainer *Node // = doc
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allClosed bool
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}
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// NewParser creates a markdown parser with CommonExtensions.
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func NewParser() *Parser {
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return NewParserWithExtensions(CommonExtensions)
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}
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// NewParserWithExtensions creates a markdown parser with given extensions.
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// Before
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// for Run() to customize parser's behavior and the renderer.
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func NewParserWithExtensions(extension Extensions) *Parser {
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p := Parser{
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refs: make(map[string]*reference),
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maxNesting: 16,
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insideLink: false,
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Doc: NewNode(&DocumentData{}),
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extensions: extension,
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allClosed: true,
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}
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p.tip = p.Doc
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p.oldTip = p.Doc
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p.lastMatchedContainer = p.Doc
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p.inlineCallback[' '] = maybeLineBreak
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p.inlineCallback['*'] = emphasis
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p.inlineCallback['_'] = emphasis
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if p.extensions&Strikethrough != 0 {
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p.inlineCallback['~'] = emphasis
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}
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p.inlineCallback['`'] = codeSpan
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p.inlineCallback['\n'] = lineBreak
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p.inlineCallback['['] = link
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p.inlineCallback['<'] = leftAngle
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p.inlineCallback['\\'] = escape
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p.inlineCallback['&'] = entity
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p.inlineCallback['!'] = maybeImage
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p.inlineCallback['^'] = maybeInlineFootnote
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if p.extensions&Autolink != 0 {
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p.inlineCallback['h'] = maybeAutoLink
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p.inlineCallback['m'] = maybeAutoLink
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p.inlineCallback['f'] = maybeAutoLink
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p.inlineCallback['H'] = maybeAutoLink
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p.inlineCallback['M'] = maybeAutoLink
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p.inlineCallback['F'] = maybeAutoLink
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}
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if p.extensions&Footnotes != 0 {
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p.notes = make([]*reference, 0)
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}
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return &p
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}
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func (p *Parser) getRef(refid string) (ref *reference, found bool) {
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if p.ReferenceOverride != nil {
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r, overridden := p.ReferenceOverride(refid)
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if overridden {
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if r == nil {
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return nil, false
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}
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return &reference{
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link: []byte(r.Link),
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title: []byte(r.Title),
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noteID: 0,
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hasBlock: false,
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text: []byte(r.Text)}, true
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}
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}
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// refs are case insensitive
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ref, found = p.refs[strings.ToLower(refid)]
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return ref, found
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}
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func (p *Parser) finalize(block *Node) {
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above := block.Parent
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block.open = false
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p.tip = above
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}
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func (p *Parser) addChild(d NodeData, offset uint32) *Node {
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return p.addExistingChild(NewNode(d), offset)
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}
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func (p *Parser) addExistingChild(node *Node, offset uint32) *Node {
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for !p.tip.canContain(node.Data) {
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p.finalize(p.tip)
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}
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p.tip.AppendChild(node)
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p.tip = node
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return node
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}
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func (p *Parser) closeUnmatchedBlocks() {
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if !p.allClosed {
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for p.oldTip != p.lastMatchedContainer {
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parent := p.oldTip.Parent
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p.finalize(p.oldTip)
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p.oldTip = parent
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}
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p.allClosed = true
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}
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}
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// Reference represents the details of a link.
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// See the documentation in Options for more details on use-case.
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type Reference struct {
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// Link is usually the URL the reference points to.
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Link string
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// Title is the alternate text describing the link in more detail.
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Title string
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// Text is the optional text to override the ref with if the syntax used was
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// [refid][]
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Text string
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}
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// ToHTML converts a markdown text in input and converts it to HTML.
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//
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// You can optionally pass a parser and renderer, which allows to customize
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@ -339,564 +64,3 @@ func ToHTML(input []byte, parser *Parser, renderer Renderer) []byte {
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parser.Parse(input)
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return parser.Render(renderer)
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}
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// Render renders a parsed data in parser with a given renderer
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func (p *Parser) Render(renderer Renderer) []byte {
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var buf bytes.Buffer
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ast := p.Doc
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renderer.RenderHeader(&buf, ast)
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ast.Walk(func(node *Node, entering bool) WalkStatus {
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return renderer.RenderNode(&buf, node, entering)
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})
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renderer.RenderFooter(&buf, ast)
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return buf.Bytes()
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}
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// Parse is an entry point to the parsing part of Blackfriday. It takes an
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// input markdown document and produces a syntax tree for its contents. This
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// tree can then be rendered with a default or custom renderer, or
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// analyzed/transformed by the caller to whatever non-standard needs they have.
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// The return value is the root node of the syntax tree.
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func (p *Parser) Parse(input []byte) *Node {
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p.block(input)
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// Walk the tree and finish up some of unfinished blocks
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for p.tip != nil {
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p.finalize(p.tip)
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}
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// Walk the tree again and process inline markdown in each block
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p.Doc.Walk(func(node *Node, entering bool) WalkStatus {
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switch node.Data.(type) {
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case *ParagraphData, *HeadingData, *TableCellData:
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p.inline(node, node.content)
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node.content = nil
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}
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return GoToNext
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})
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p.parseRefsToAST()
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return p.Doc
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}
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func (p *Parser) parseRefsToAST() {
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if p.extensions&Footnotes == 0 || len(p.notes) == 0 {
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return
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}
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p.tip = p.Doc
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d := &ListData{
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IsFootnotesList: true,
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ListFlags: ListTypeOrdered,
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}
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block := p.addBlock(d, nil)
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flags := ListItemBeginningOfList
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// Note: this loop is intentionally explicit, not range-form. This is
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// because the body of the loop will append nested footnotes to p.notes and
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// we need to process those late additions. Range form would only walk over
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// the fixed initial set.
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for i := 0; i < len(p.notes); i++ {
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ref := p.notes[i]
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p.addExistingChild(ref.footnote, 0)
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block := ref.footnote
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blockData := block.Data.(*ItemData)
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blockData.ListFlags = flags | ListTypeOrdered
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blockData.RefLink = ref.link
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if ref.hasBlock {
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flags |= ListItemContainsBlock
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p.block(ref.title)
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} else {
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p.inline(block, ref.title)
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}
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flags &^= ListItemBeginningOfList | ListItemContainsBlock
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}
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above := block.Parent
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finalizeList(block, d)
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p.tip = above
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block.Walk(func(node *Node, entering bool) WalkStatus {
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switch node.Data.(type) {
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case *ParagraphData, *HeadingData:
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p.inline(node, node.content)
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node.content = nil
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}
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return GoToNext
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})
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}
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//
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// Link references
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//
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// This section implements support for references that (usually) appear
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// as footnotes in a document, and can be referenced anywhere in the document.
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// The basic format is:
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//
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// [1]: http://www.google.com/ "Google"
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// [2]: http://www.github.com/ "Github"
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//
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// Anywhere in the document, the reference can be linked by referring to its
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// label, i.e., 1 and 2 in this example, as in:
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//
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// This library is hosted on [Github][2], a git hosting site.
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//
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// Actual footnotes as specified in Pandoc and supported by some other Markdown
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// libraries such as php-markdown are also taken care of. They look like this:
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//
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// This sentence needs a bit of further explanation.[^note]
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//
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// [^note]: This is the explanation.
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//
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// Footnotes should be placed at the end of the document in an ordered list.
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// Inline footnotes such as:
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//
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// Inline footnotes^[Not supported.] also exist.
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//
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// are not yet supported.
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// reference holds all information necessary for a reference-style links or
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// footnotes.
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//
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// Consider this markdown with reference-style links:
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//
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// [link][ref]
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//
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// [ref]: /url/ "tooltip title"
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//
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// It will be ultimately converted to this HTML:
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//
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// <p><a href=\"/url/\" title=\"title\">link</a></p>
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//
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// And a reference structure will be populated as follows:
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//
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// p.refs["ref"] = &reference{
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// link: "/url/",
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// title: "tooltip title",
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// }
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//
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// Alternatively, reference can contain information about a footnote. Consider
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// this markdown:
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//
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// Text needing a footnote.[^a]
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//
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// [^a]: This is the note
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//
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// A reference structure will be populated as follows:
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//
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// p.refs["a"] = &reference{
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// link: "a",
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// title: "This is the note",
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// noteID: <some positive int>,
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// }
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//
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// TODO: As you can see, it begs for splitting into two dedicated structures
|
||||
// for refs and for footnotes.
|
||||
type reference struct {
|
||||
link []byte
|
||||
title []byte
|
||||
noteID int // 0 if not a footnote ref
|
||||
hasBlock bool
|
||||
footnote *Node // a link to the Item node within a list of footnotes
|
||||
|
||||
text []byte // only gets populated by refOverride feature with Reference.Text
|
||||
}
|
||||
|
||||
func (r *reference) String() string {
|
||||
return fmt.Sprintf("{link: %q, title: %q, text: %q, noteID: %d, hasBlock: %v}",
|
||||
r.link, r.title, r.text, r.noteID, r.hasBlock)
|
||||
}
|
||||
|
||||
// Check whether or not data starts with a reference link.
|
||||
// If so, it is parsed and stored in the list of references
|
||||
// (in the render struct).
|
||||
// Returns the number of bytes to skip to move past it,
|
||||
// or zero if the first line is not a reference.
|
||||
func isReference(p *Parser, data []byte, tabSize int) int {
|
||||
// up to 3 optional leading spaces
|
||||
if len(data) < 4 {
|
||||
return 0
|
||||
}
|
||||
i := 0
|
||||
for i < 3 && data[i] == ' ' {
|
||||
i++
|
||||
}
|
||||
|
||||
noteID := 0
|
||||
|
||||
// id part: anything but a newline between brackets
|
||||
if data[i] != '[' {
|
||||
return 0
|
||||
}
|
||||
i++
|
||||
if p.extensions&Footnotes != 0 {
|
||||
if i < len(data) && data[i] == '^' {
|
||||
// we can set it to anything here because the proper noteIds will
|
||||
// be assigned later during the second pass. It just has to be != 0
|
||||
noteID = 1
|
||||
i++
|
||||
}
|
||||
}
|
||||
idOffset := i
|
||||
for i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != ']' {
|
||||
i++
|
||||
}
|
||||
if i >= len(data) || data[i] != ']' {
|
||||
return 0
|
||||
}
|
||||
idEnd := i
|
||||
// footnotes can have empty ID, like this: [^], but a reference can not be
|
||||
// empty like this: []. Break early if it's not a footnote and there's no ID
|
||||
if noteID == 0 && idOffset == idEnd {
|
||||
return 0
|
||||
}
|
||||
// spacer: colon (space | tab)* newline? (space | tab)*
|
||||
i++
|
||||
if i >= len(data) || data[i] != ':' {
|
||||
return 0
|
||||
}
|
||||
i++
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
if i < len(data) && (data[i] == '\n' || data[i] == '\r') {
|
||||
i++
|
||||
if i < len(data) && data[i] == '\n' && data[i-1] == '\r' {
|
||||
i++
|
||||
}
|
||||
}
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
if i >= len(data) {
|
||||
return 0
|
||||
}
|
||||
|
||||
var (
|
||||
linkOffset, linkEnd int
|
||||
titleOffset, titleEnd int
|
||||
lineEnd int
|
||||
raw []byte
|
||||
hasBlock bool
|
||||
)
|
||||
|
||||
if p.extensions&Footnotes != 0 && noteID != 0 {
|
||||
linkOffset, linkEnd, raw, hasBlock = scanFootnote(p, data, i, tabSize)
|
||||
lineEnd = linkEnd
|
||||
} else {
|
||||
linkOffset, linkEnd, titleOffset, titleEnd, lineEnd = scanLinkRef(p, data, i)
|
||||
}
|
||||
if lineEnd == 0 {
|
||||
return 0
|
||||
}
|
||||
|
||||
// a valid ref has been found
|
||||
|
||||
ref := &reference{
|
||||
noteID: noteID,
|
||||
hasBlock: hasBlock,
|
||||
}
|
||||
|
||||
if noteID > 0 {
|
||||
// reusing the link field for the id since footnotes don't have links
|
||||
ref.link = data[idOffset:idEnd]
|
||||
// if footnote, it's not really a title, it's the contained text
|
||||
ref.title = raw
|
||||
} else {
|
||||
ref.link = data[linkOffset:linkEnd]
|
||||
ref.title = data[titleOffset:titleEnd]
|
||||
}
|
||||
|
||||
// id matches are case-insensitive
|
||||
id := string(bytes.ToLower(data[idOffset:idEnd]))
|
||||
|
||||
p.refs[id] = ref
|
||||
|
||||
return lineEnd
|
||||
}
|
||||
|
||||
func scanLinkRef(p *Parser, data []byte, i int) (linkOffset, linkEnd, titleOffset, titleEnd, lineEnd int) {
|
||||
// link: whitespace-free sequence, optionally between angle brackets
|
||||
if data[i] == '<' {
|
||||
i++
|
||||
}
|
||||
linkOffset = i
|
||||
for i < len(data) && data[i] != ' ' && data[i] != '\t' && data[i] != '\n' && data[i] != '\r' {
|
||||
i++
|
||||
}
|
||||
linkEnd = i
|
||||
if data[linkOffset] == '<' && data[linkEnd-1] == '>' {
|
||||
linkOffset++
|
||||
linkEnd--
|
||||
}
|
||||
|
||||
// optional spacer: (space | tab)* (newline | '\'' | '"' | '(' )
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
if i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != '\'' && data[i] != '"' && data[i] != '(' {
|
||||
return
|
||||
}
|
||||
|
||||
// compute end-of-line
|
||||
if i >= len(data) || data[i] == '\r' || data[i] == '\n' {
|
||||
lineEnd = i
|
||||
}
|
||||
if i+1 < len(data) && data[i] == '\r' && data[i+1] == '\n' {
|
||||
lineEnd++
|
||||
}
|
||||
|
||||
// optional (space|tab)* spacer after a newline
|
||||
if lineEnd > 0 {
|
||||
i = lineEnd + 1
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
}
|
||||
|
||||
// optional title: any non-newline sequence enclosed in '"() alone on its line
|
||||
if i+1 < len(data) && (data[i] == '\'' || data[i] == '"' || data[i] == '(') {
|
||||
i++
|
||||
titleOffset = i
|
||||
|
||||
// look for EOL
|
||||
for i < len(data) && data[i] != '\n' && data[i] != '\r' {
|
||||
i++
|
||||
}
|
||||
if i+1 < len(data) && data[i] == '\n' && data[i+1] == '\r' {
|
||||
titleEnd = i + 1
|
||||
} else {
|
||||
titleEnd = i
|
||||
}
|
||||
|
||||
// step back
|
||||
i--
|
||||
for i > titleOffset && (data[i] == ' ' || data[i] == '\t') {
|
||||
i--
|
||||
}
|
||||
if i > titleOffset && (data[i] == '\'' || data[i] == '"' || data[i] == ')') {
|
||||
lineEnd = titleEnd
|
||||
titleEnd = i
|
||||
}
|
||||
}
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
// The first bit of this logic is the same as Parser.listItem, but the rest
|
||||
// is much simpler. This function simply finds the entire block and shifts it
|
||||
// over by one tab if it is indeed a block (just returns the line if it's not).
|
||||
// blockEnd is the end of the section in the input buffer, and contents is the
|
||||
// extracted text that was shifted over one tab. It will need to be rendered at
|
||||
// the end of the document.
|
||||
func scanFootnote(p *Parser, data []byte, i, indentSize int) (blockStart, blockEnd int, contents []byte, hasBlock bool) {
|
||||
if i == 0 || len(data) == 0 {
|
||||
return
|
||||
}
|
||||
|
||||
// skip leading whitespace on first line
|
||||
for i < len(data) && data[i] == ' ' {
|
||||
i++
|
||||
}
|
||||
|
||||
blockStart = i
|
||||
|
||||
// find the end of the line
|
||||
blockEnd = i
|
||||
for i < len(data) && data[i-1] != '\n' {
|
||||
i++
|
||||
}
|
||||
|
||||
// get working buffer
|
||||
var raw bytes.Buffer
|
||||
|
||||
// put the first line into the working buffer
|
||||
raw.Write(data[blockEnd:i])
|
||||
blockEnd = i
|
||||
|
||||
// process the following lines
|
||||
containsBlankLine := false
|
||||
|
||||
gatherLines:
|
||||
for blockEnd < len(data) {
|
||||
i++
|
||||
|
||||
// find the end of this line
|
||||
for i < len(data) && 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[blockEnd:i]) > 0 {
|
||||
containsBlankLine = true
|
||||
blockEnd = i
|
||||
continue
|
||||
}
|
||||
|
||||
n := 0
|
||||
if n = isIndented(data[blockEnd:i], indentSize); n == 0 {
|
||||
// this is the end of the block.
|
||||
// we don't want to include this last line in the index.
|
||||
break gatherLines
|
||||
}
|
||||
|
||||
// if there were blank lines before this one, insert a new one now
|
||||
if containsBlankLine {
|
||||
raw.WriteByte('\n')
|
||||
containsBlankLine = false
|
||||
}
|
||||
|
||||
// get rid of that first tab, write to buffer
|
||||
raw.Write(data[blockEnd+n : i])
|
||||
hasBlock = true
|
||||
|
||||
blockEnd = i
|
||||
}
|
||||
|
||||
if data[blockEnd-1] != '\n' {
|
||||
raw.WriteByte('\n')
|
||||
}
|
||||
|
||||
contents = raw.Bytes()
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
//
|
||||
//
|
||||
// Miscellaneous helper functions
|
||||
//
|
||||
//
|
||||
|
||||
// Test if a character is a punctuation symbol.
|
||||
// Taken from a private function in regexp in the stdlib.
|
||||
func ispunct(c byte) bool {
|
||||
for _, r := range []byte("!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~") {
|
||||
if c == r {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
// Test if a character is a whitespace character.
|
||||
func isspace(c byte) bool {
|
||||
return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == '\v'
|
||||
}
|
||||
|
||||
// Test if a character is letter.
|
||||
func isletter(c byte) bool {
|
||||
return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
|
||||
}
|
||||
|
||||
// Test if a character is a letter or a digit.
|
||||
// TODO: check when this is looking for ASCII alnum and when it should use unicode
|
||||
func isalnum(c byte) bool {
|
||||
return (c >= '0' && c <= '9') || isletter(c)
|
||||
}
|
||||
|
||||
// Replace tab characters with spaces, aligning to the next TAB_SIZE column.
|
||||
// always ends output with a newline
|
||||
func expandTabs(out *bytes.Buffer, line []byte, tabSize int) {
|
||||
// first, check for common cases: no tabs, or only tabs at beginning of line
|
||||
i, prefix := 0, 0
|
||||
slowcase := false
|
||||
for i = 0; i < len(line); i++ {
|
||||
if line[i] == '\t' {
|
||||
if prefix == i {
|
||||
prefix++
|
||||
} else {
|
||||
slowcase = true
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// no need to decode runes if all tabs are at the beginning of the line
|
||||
if !slowcase {
|
||||
for i = 0; i < prefix*tabSize; i++ {
|
||||
out.WriteByte(' ')
|
||||
}
|
||||
out.Write(line[prefix:])
|
||||
return
|
||||
}
|
||||
|
||||
// the slow case: we need to count runes to figure out how
|
||||
// many spaces to insert for each tab
|
||||
column := 0
|
||||
i = 0
|
||||
for i < len(line) {
|
||||
start := i
|
||||
for i < len(line) && line[i] != '\t' {
|
||||
_, size := utf8.DecodeRune(line[i:])
|
||||
i += size
|
||||
column++
|
||||
}
|
||||
|
||||
if i > start {
|
||||
out.Write(line[start:i])
|
||||
}
|
||||
|
||||
if i >= len(line) {
|
||||
break
|
||||
}
|
||||
|
||||
for {
|
||||
out.WriteByte(' ')
|
||||
column++
|
||||
if column%tabSize == 0 {
|
||||
break
|
||||
}
|
||||
}
|
||||
|
||||
i++
|
||||
}
|
||||
}
|
||||
|
||||
// Find if a line counts as indented or not.
|
||||
// Returns number of characters the indent is (0 = not indented).
|
||||
func isIndented(data []byte, indentSize int) int {
|
||||
if len(data) == 0 {
|
||||
return 0
|
||||
}
|
||||
if data[0] == '\t' {
|
||||
return 1
|
||||
}
|
||||
if len(data) < indentSize {
|
||||
return 0
|
||||
}
|
||||
for i := 0; i < indentSize; i++ {
|
||||
if data[i] != ' ' {
|
||||
return 0
|
||||
}
|
||||
}
|
||||
return indentSize
|
||||
}
|
||||
|
||||
// Create a url-safe slug for fragments
|
||||
func slugify(in []byte) []byte {
|
||||
if len(in) == 0 {
|
||||
return in
|
||||
}
|
||||
out := make([]byte, 0, len(in))
|
||||
sym := false
|
||||
|
||||
for _, ch := range in {
|
||||
if isalnum(ch) {
|
||||
sym = false
|
||||
out = append(out, ch)
|
||||
} else if sym {
|
||||
continue
|
||||
} else {
|
||||
out = append(out, '-')
|
||||
sym = true
|
||||
}
|
||||
}
|
||||
var a, b int
|
||||
var ch byte
|
||||
for a, ch = range out {
|
||||
if ch != '-' {
|
||||
break
|
||||
}
|
||||
}
|
||||
for b = len(out) - 1; b > 0; b-- {
|
||||
if out[b] != '-' {
|
||||
break
|
||||
}
|
||||
}
|
||||
return out[a : b+1]
|
||||
}
|
||||
|
|
|
|||
|
|
@ -0,0 +1,795 @@
|
|||
package markdown
|
||||
|
||||
// Callback functions for inline parsing. One such function is defined
|
||||
import (
|
||||
"bytes"
|
||||
"fmt"
|
||||
"strings"
|
||||
"unicode/utf8"
|
||||
)
|
||||
|
||||
// Extensions is a bitmask of enabled Parser extensions.
|
||||
type Extensions int
|
||||
|
||||
// Bit flags representing markdown parsing extensions.
|
||||
// Use | (or) to specify multiple extensions.
|
||||
const (
|
||||
NoExtensions Extensions = 0
|
||||
NoIntraEmphasis Extensions = 1 << iota // Ignore emphasis markers inside words
|
||||
Tables // Render tables
|
||||
FencedCode // Render fenced code blocks
|
||||
Autolink // Detect embedded URLs that are not explicitly marked
|
||||
Strikethrough // Strikethrough text using ~~test~~
|
||||
LaxHTMLBlocks // Loosen up HTML block parsing rules
|
||||
SpaceHeadings // Be strict about prefix heading rules
|
||||
HardLineBreak // Translate newlines into line breaks
|
||||
TabSizeEight // Expand tabs to eight spaces instead of four
|
||||
Footnotes // Pandoc-style footnotes
|
||||
NoEmptyLineBeforeBlock // No need to insert an empty line to start a (code, quote, ordered list, unordered list) block
|
||||
HeadingIDs // specify heading IDs with {#id}
|
||||
Titleblock // Titleblock ala pandoc
|
||||
AutoHeadingIDs // Create the heading ID from the text
|
||||
BackslashLineBreak // Translate trailing backslashes into line breaks
|
||||
DefinitionLists // Render definition lists
|
||||
|
||||
CommonExtensions Extensions = NoIntraEmphasis | Tables | FencedCode |
|
||||
Autolink | Strikethrough | SpaceHeadings | HeadingIDs |
|
||||
BackslashLineBreak | DefinitionLists
|
||||
)
|
||||
|
||||
// ListType contains bitwise or'ed flags for list and list item objects.
|
||||
type ListType int
|
||||
|
||||
// These are the possible flag values for the ListItem renderer.
|
||||
// Multiple flag values may be ORed together.
|
||||
// These are mostly of interest if you are writing a new output format.
|
||||
const (
|
||||
ListTypeOrdered ListType = 1 << iota
|
||||
ListTypeDefinition
|
||||
ListTypeTerm
|
||||
|
||||
ListItemContainsBlock
|
||||
ListItemBeginningOfList // TODO: figure out if this is of any use now
|
||||
ListItemEndOfList
|
||||
)
|
||||
|
||||
// CellAlignFlags holds a type of alignment in a table cell.
|
||||
type CellAlignFlags int
|
||||
|
||||
// These are the possible flag values for the table cell renderer.
|
||||
// Only a single one of these values will be used; they are not ORed together.
|
||||
// These are mostly of interest if you are writing a new output format.
|
||||
const (
|
||||
TableAlignmentLeft CellAlignFlags = 1 << iota
|
||||
TableAlignmentRight
|
||||
TableAlignmentCenter = (TableAlignmentLeft | TableAlignmentRight)
|
||||
)
|
||||
|
||||
// The size of a tab stop.
|
||||
const (
|
||||
TabSizeDefault = 4
|
||||
TabSizeDouble = 8
|
||||
)
|
||||
|
||||
// for each character that triggers a response when parsing inline data.
|
||||
type inlineParser func(p *Parser, data []byte, offset int) (int, *Node)
|
||||
|
||||
// ReferenceOverrideFunc is expected to be called with a reference string and
|
||||
// return either a valid Reference type that the reference string maps to or
|
||||
// nil. If overridden is false, the default reference logic will be executed.
|
||||
// See the documentation in Options for more details on use-case.
|
||||
type ReferenceOverrideFunc func(reference string) (ref *Reference, overridden bool)
|
||||
|
||||
// Parser is a type that holds extensions and the runtime state used by
|
||||
// Parse, and the renderer. You can not use it directly, construct it with New.
|
||||
type Parser struct {
|
||||
|
||||
// ReferenceOverride is an optional function callback that is called every
|
||||
// time a reference is resolved. It can be set before starting parsing.
|
||||
//
|
||||
// In Markdown, the link reference syntax can be made to resolve a link to
|
||||
// a reference instead of an inline URL, in one of the following ways:
|
||||
//
|
||||
// * [link text][refid]
|
||||
// * [refid][]
|
||||
//
|
||||
// Usually, the refid is defined at the bottom of the Markdown document. If
|
||||
// this override function is provided, the refid is passed to the override
|
||||
// function first, before consulting the defined refids at the bottom. If
|
||||
// the override function indicates an override did not occur, the refids at
|
||||
// the bottom will be used to fill in the link details.
|
||||
ReferenceOverride ReferenceOverrideFunc
|
||||
|
||||
// after parsing, this is root of parsed ast
|
||||
Doc *Node
|
||||
|
||||
extensions Extensions
|
||||
|
||||
refs map[string]*reference
|
||||
inlineCallback [256]inlineParser
|
||||
nesting int
|
||||
maxNesting int
|
||||
insideLink bool
|
||||
|
||||
// Footnotes need to be ordered as well as available to quickly check for
|
||||
// presence. If a ref is also a footnote, it's stored both in refs and here
|
||||
// in notes. Slice is nil if footnotes not enabled.
|
||||
notes []*reference
|
||||
|
||||
tip *Node // = doc
|
||||
oldTip *Node
|
||||
lastMatchedContainer *Node // = doc
|
||||
allClosed bool
|
||||
}
|
||||
|
||||
// NewParser creates a markdown parser with CommonExtensions.
|
||||
func NewParser() *Parser {
|
||||
return NewParserWithExtensions(CommonExtensions)
|
||||
}
|
||||
|
||||
// NewParserWithExtensions creates a markdown parser with given extensions.
|
||||
// Before
|
||||
// for Run() to customize parser's behavior and the renderer.
|
||||
func NewParserWithExtensions(extension Extensions) *Parser {
|
||||
p := Parser{
|
||||
refs: make(map[string]*reference),
|
||||
maxNesting: 16,
|
||||
insideLink: false,
|
||||
Doc: NewNode(&DocumentData{}),
|
||||
extensions: extension,
|
||||
allClosed: true,
|
||||
}
|
||||
p.tip = p.Doc
|
||||
p.oldTip = p.Doc
|
||||
p.lastMatchedContainer = p.Doc
|
||||
|
||||
p.inlineCallback[' '] = maybeLineBreak
|
||||
p.inlineCallback['*'] = emphasis
|
||||
p.inlineCallback['_'] = emphasis
|
||||
if p.extensions&Strikethrough != 0 {
|
||||
p.inlineCallback['~'] = emphasis
|
||||
}
|
||||
p.inlineCallback['`'] = codeSpan
|
||||
p.inlineCallback['\n'] = lineBreak
|
||||
p.inlineCallback['['] = link
|
||||
p.inlineCallback['<'] = leftAngle
|
||||
p.inlineCallback['\\'] = escape
|
||||
p.inlineCallback['&'] = entity
|
||||
p.inlineCallback['!'] = maybeImage
|
||||
p.inlineCallback['^'] = maybeInlineFootnote
|
||||
if p.extensions&Autolink != 0 {
|
||||
p.inlineCallback['h'] = maybeAutoLink
|
||||
p.inlineCallback['m'] = maybeAutoLink
|
||||
p.inlineCallback['f'] = maybeAutoLink
|
||||
p.inlineCallback['H'] = maybeAutoLink
|
||||
p.inlineCallback['M'] = maybeAutoLink
|
||||
p.inlineCallback['F'] = maybeAutoLink
|
||||
}
|
||||
if p.extensions&Footnotes != 0 {
|
||||
p.notes = make([]*reference, 0)
|
||||
}
|
||||
return &p
|
||||
}
|
||||
|
||||
func (p *Parser) getRef(refid string) (ref *reference, found bool) {
|
||||
if p.ReferenceOverride != nil {
|
||||
r, overridden := p.ReferenceOverride(refid)
|
||||
if overridden {
|
||||
if r == nil {
|
||||
return nil, false
|
||||
}
|
||||
return &reference{
|
||||
link: []byte(r.Link),
|
||||
title: []byte(r.Title),
|
||||
noteID: 0,
|
||||
hasBlock: false,
|
||||
text: []byte(r.Text)}, true
|
||||
}
|
||||
}
|
||||
// refs are case insensitive
|
||||
ref, found = p.refs[strings.ToLower(refid)]
|
||||
return ref, found
|
||||
}
|
||||
|
||||
func (p *Parser) finalize(block *Node) {
|
||||
above := block.Parent
|
||||
block.open = false
|
||||
p.tip = above
|
||||
}
|
||||
|
||||
func (p *Parser) addChild(d NodeData, offset uint32) *Node {
|
||||
return p.addExistingChild(NewNode(d), offset)
|
||||
}
|
||||
|
||||
func (p *Parser) addExistingChild(node *Node, offset uint32) *Node {
|
||||
for !p.tip.canContain(node.Data) {
|
||||
p.finalize(p.tip)
|
||||
}
|
||||
p.tip.AppendChild(node)
|
||||
p.tip = node
|
||||
return node
|
||||
}
|
||||
|
||||
func (p *Parser) closeUnmatchedBlocks() {
|
||||
if !p.allClosed {
|
||||
for p.oldTip != p.lastMatchedContainer {
|
||||
parent := p.oldTip.Parent
|
||||
p.finalize(p.oldTip)
|
||||
p.oldTip = parent
|
||||
}
|
||||
p.allClosed = true
|
||||
}
|
||||
}
|
||||
|
||||
// Reference represents the details of a link.
|
||||
// See the documentation in Options for more details on use-case.
|
||||
type Reference struct {
|
||||
// Link is usually the URL the reference points to.
|
||||
Link string
|
||||
// Title is the alternate text describing the link in more detail.
|
||||
Title string
|
||||
// Text is the optional text to override the ref with if the syntax used was
|
||||
// [refid][]
|
||||
Text string
|
||||
}
|
||||
|
||||
// Render renders a parsed data in parser with a given renderer
|
||||
func (p *Parser) Render(renderer Renderer) []byte {
|
||||
var buf bytes.Buffer
|
||||
ast := p.Doc
|
||||
renderer.RenderHeader(&buf, ast)
|
||||
ast.Walk(func(node *Node, entering bool) WalkStatus {
|
||||
return renderer.RenderNode(&buf, node, entering)
|
||||
})
|
||||
renderer.RenderFooter(&buf, ast)
|
||||
return buf.Bytes()
|
||||
}
|
||||
|
||||
// Parse is an entry point to the parsing part of Blackfriday. It takes an
|
||||
// input markdown document and produces a syntax tree for its contents. This
|
||||
// tree can then be rendered with a default or custom renderer, or
|
||||
// analyzed/transformed by the caller to whatever non-standard needs they have.
|
||||
// The return value is the root node of the syntax tree.
|
||||
func (p *Parser) Parse(input []byte) *Node {
|
||||
p.block(input)
|
||||
// Walk the tree and finish up some of unfinished blocks
|
||||
for p.tip != nil {
|
||||
p.finalize(p.tip)
|
||||
}
|
||||
// Walk the tree again and process inline markdown in each block
|
||||
p.Doc.Walk(func(node *Node, entering bool) WalkStatus {
|
||||
switch node.Data.(type) {
|
||||
case *ParagraphData, *HeadingData, *TableCellData:
|
||||
p.inline(node, node.content)
|
||||
node.content = nil
|
||||
}
|
||||
return GoToNext
|
||||
})
|
||||
p.parseRefsToAST()
|
||||
return p.Doc
|
||||
}
|
||||
|
||||
func (p *Parser) parseRefsToAST() {
|
||||
if p.extensions&Footnotes == 0 || len(p.notes) == 0 {
|
||||
return
|
||||
}
|
||||
p.tip = p.Doc
|
||||
d := &ListData{
|
||||
IsFootnotesList: true,
|
||||
ListFlags: ListTypeOrdered,
|
||||
}
|
||||
block := p.addBlock(d, nil)
|
||||
flags := ListItemBeginningOfList
|
||||
// Note: this loop is intentionally explicit, not range-form. This is
|
||||
// because the body of the loop will append nested footnotes to p.notes and
|
||||
// we need to process those late additions. Range form would only walk over
|
||||
// the fixed initial set.
|
||||
for i := 0; i < len(p.notes); i++ {
|
||||
ref := p.notes[i]
|
||||
p.addExistingChild(ref.footnote, 0)
|
||||
block := ref.footnote
|
||||
blockData := block.Data.(*ItemData)
|
||||
blockData.ListFlags = flags | ListTypeOrdered
|
||||
blockData.RefLink = ref.link
|
||||
if ref.hasBlock {
|
||||
flags |= ListItemContainsBlock
|
||||
p.block(ref.title)
|
||||
} else {
|
||||
p.inline(block, ref.title)
|
||||
}
|
||||
flags &^= ListItemBeginningOfList | ListItemContainsBlock
|
||||
}
|
||||
above := block.Parent
|
||||
finalizeList(block, d)
|
||||
p.tip = above
|
||||
block.Walk(func(node *Node, entering bool) WalkStatus {
|
||||
switch node.Data.(type) {
|
||||
case *ParagraphData, *HeadingData:
|
||||
p.inline(node, node.content)
|
||||
node.content = nil
|
||||
}
|
||||
return GoToNext
|
||||
})
|
||||
}
|
||||
|
||||
//
|
||||
// Link references
|
||||
//
|
||||
// This section implements support for references that (usually) appear
|
||||
// as footnotes in a document, and can be referenced anywhere in the document.
|
||||
// The basic format is:
|
||||
//
|
||||
// [1]: http://www.google.com/ "Google"
|
||||
// [2]: http://www.github.com/ "Github"
|
||||
//
|
||||
// Anywhere in the document, the reference can be linked by referring to its
|
||||
// label, i.e., 1 and 2 in this example, as in:
|
||||
//
|
||||
// This library is hosted on [Github][2], a git hosting site.
|
||||
//
|
||||
// Actual footnotes as specified in Pandoc and supported by some other Markdown
|
||||
// libraries such as php-markdown are also taken care of. They look like this:
|
||||
//
|
||||
// This sentence needs a bit of further explanation.[^note]
|
||||
//
|
||||
// [^note]: This is the explanation.
|
||||
//
|
||||
// Footnotes should be placed at the end of the document in an ordered list.
|
||||
// Inline footnotes such as:
|
||||
//
|
||||
// Inline footnotes^[Not supported.] also exist.
|
||||
//
|
||||
// are not yet supported.
|
||||
|
||||
// reference holds all information necessary for a reference-style links or
|
||||
// footnotes.
|
||||
//
|
||||
// Consider this markdown with reference-style links:
|
||||
//
|
||||
// [link][ref]
|
||||
//
|
||||
// [ref]: /url/ "tooltip title"
|
||||
//
|
||||
// It will be ultimately converted to this HTML:
|
||||
//
|
||||
// <p><a href=\"/url/\" title=\"title\">link</a></p>
|
||||
//
|
||||
// And a reference structure will be populated as follows:
|
||||
//
|
||||
// p.refs["ref"] = &reference{
|
||||
// link: "/url/",
|
||||
// title: "tooltip title",
|
||||
// }
|
||||
//
|
||||
// Alternatively, reference can contain information about a footnote. Consider
|
||||
// this markdown:
|
||||
//
|
||||
// Text needing a footnote.[^a]
|
||||
//
|
||||
// [^a]: This is the note
|
||||
//
|
||||
// A reference structure will be populated as follows:
|
||||
//
|
||||
// p.refs["a"] = &reference{
|
||||
// link: "a",
|
||||
// title: "This is the note",
|
||||
// noteID: <some positive int>,
|
||||
// }
|
||||
//
|
||||
// TODO: As you can see, it begs for splitting into two dedicated structures
|
||||
// for refs and for footnotes.
|
||||
type reference struct {
|
||||
link []byte
|
||||
title []byte
|
||||
noteID int // 0 if not a footnote ref
|
||||
hasBlock bool
|
||||
footnote *Node // a link to the Item node within a list of footnotes
|
||||
|
||||
text []byte // only gets populated by refOverride feature with Reference.Text
|
||||
}
|
||||
|
||||
func (r *reference) String() string {
|
||||
return fmt.Sprintf("{link: %q, title: %q, text: %q, noteID: %d, hasBlock: %v}",
|
||||
r.link, r.title, r.text, r.noteID, r.hasBlock)
|
||||
}
|
||||
|
||||
// Check whether or not data starts with a reference link.
|
||||
// If so, it is parsed and stored in the list of references
|
||||
// (in the render struct).
|
||||
// Returns the number of bytes to skip to move past it,
|
||||
// or zero if the first line is not a reference.
|
||||
func isReference(p *Parser, data []byte, tabSize int) int {
|
||||
// up to 3 optional leading spaces
|
||||
if len(data) < 4 {
|
||||
return 0
|
||||
}
|
||||
i := 0
|
||||
for i < 3 && data[i] == ' ' {
|
||||
i++
|
||||
}
|
||||
|
||||
noteID := 0
|
||||
|
||||
// id part: anything but a newline between brackets
|
||||
if data[i] != '[' {
|
||||
return 0
|
||||
}
|
||||
i++
|
||||
if p.extensions&Footnotes != 0 {
|
||||
if i < len(data) && data[i] == '^' {
|
||||
// we can set it to anything here because the proper noteIds will
|
||||
// be assigned later during the second pass. It just has to be != 0
|
||||
noteID = 1
|
||||
i++
|
||||
}
|
||||
}
|
||||
idOffset := i
|
||||
for i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != ']' {
|
||||
i++
|
||||
}
|
||||
if i >= len(data) || data[i] != ']' {
|
||||
return 0
|
||||
}
|
||||
idEnd := i
|
||||
// footnotes can have empty ID, like this: [^], but a reference can not be
|
||||
// empty like this: []. Break early if it's not a footnote and there's no ID
|
||||
if noteID == 0 && idOffset == idEnd {
|
||||
return 0
|
||||
}
|
||||
// spacer: colon (space | tab)* newline? (space | tab)*
|
||||
i++
|
||||
if i >= len(data) || data[i] != ':' {
|
||||
return 0
|
||||
}
|
||||
i++
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
if i < len(data) && (data[i] == '\n' || data[i] == '\r') {
|
||||
i++
|
||||
if i < len(data) && data[i] == '\n' && data[i-1] == '\r' {
|
||||
i++
|
||||
}
|
||||
}
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
if i >= len(data) {
|
||||
return 0
|
||||
}
|
||||
|
||||
var (
|
||||
linkOffset, linkEnd int
|
||||
titleOffset, titleEnd int
|
||||
lineEnd int
|
||||
raw []byte
|
||||
hasBlock bool
|
||||
)
|
||||
|
||||
if p.extensions&Footnotes != 0 && noteID != 0 {
|
||||
linkOffset, linkEnd, raw, hasBlock = scanFootnote(p, data, i, tabSize)
|
||||
lineEnd = linkEnd
|
||||
} else {
|
||||
linkOffset, linkEnd, titleOffset, titleEnd, lineEnd = scanLinkRef(p, data, i)
|
||||
}
|
||||
if lineEnd == 0 {
|
||||
return 0
|
||||
}
|
||||
|
||||
// a valid ref has been found
|
||||
|
||||
ref := &reference{
|
||||
noteID: noteID,
|
||||
hasBlock: hasBlock,
|
||||
}
|
||||
|
||||
if noteID > 0 {
|
||||
// reusing the link field for the id since footnotes don't have links
|
||||
ref.link = data[idOffset:idEnd]
|
||||
// if footnote, it's not really a title, it's the contained text
|
||||
ref.title = raw
|
||||
} else {
|
||||
ref.link = data[linkOffset:linkEnd]
|
||||
ref.title = data[titleOffset:titleEnd]
|
||||
}
|
||||
|
||||
// id matches are case-insensitive
|
||||
id := string(bytes.ToLower(data[idOffset:idEnd]))
|
||||
|
||||
p.refs[id] = ref
|
||||
|
||||
return lineEnd
|
||||
}
|
||||
|
||||
func scanLinkRef(p *Parser, data []byte, i int) (linkOffset, linkEnd, titleOffset, titleEnd, lineEnd int) {
|
||||
// link: whitespace-free sequence, optionally between angle brackets
|
||||
if data[i] == '<' {
|
||||
i++
|
||||
}
|
||||
linkOffset = i
|
||||
for i < len(data) && data[i] != ' ' && data[i] != '\t' && data[i] != '\n' && data[i] != '\r' {
|
||||
i++
|
||||
}
|
||||
linkEnd = i
|
||||
if data[linkOffset] == '<' && data[linkEnd-1] == '>' {
|
||||
linkOffset++
|
||||
linkEnd--
|
||||
}
|
||||
|
||||
// optional spacer: (space | tab)* (newline | '\'' | '"' | '(' )
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
if i < len(data) && data[i] != '\n' && data[i] != '\r' && data[i] != '\'' && data[i] != '"' && data[i] != '(' {
|
||||
return
|
||||
}
|
||||
|
||||
// compute end-of-line
|
||||
if i >= len(data) || data[i] == '\r' || data[i] == '\n' {
|
||||
lineEnd = i
|
||||
}
|
||||
if i+1 < len(data) && data[i] == '\r' && data[i+1] == '\n' {
|
||||
lineEnd++
|
||||
}
|
||||
|
||||
// optional (space|tab)* spacer after a newline
|
||||
if lineEnd > 0 {
|
||||
i = lineEnd + 1
|
||||
for i < len(data) && (data[i] == ' ' || data[i] == '\t') {
|
||||
i++
|
||||
}
|
||||
}
|
||||
|
||||
// optional title: any non-newline sequence enclosed in '"() alone on its line
|
||||
if i+1 < len(data) && (data[i] == '\'' || data[i] == '"' || data[i] == '(') {
|
||||
i++
|
||||
titleOffset = i
|
||||
|
||||
// look for EOL
|
||||
for i < len(data) && data[i] != '\n' && data[i] != '\r' {
|
||||
i++
|
||||
}
|
||||
if i+1 < len(data) && data[i] == '\n' && data[i+1] == '\r' {
|
||||
titleEnd = i + 1
|
||||
} else {
|
||||
titleEnd = i
|
||||
}
|
||||
|
||||
// step back
|
||||
i--
|
||||
for i > titleOffset && (data[i] == ' ' || data[i] == '\t') {
|
||||
i--
|
||||
}
|
||||
if i > titleOffset && (data[i] == '\'' || data[i] == '"' || data[i] == ')') {
|
||||
lineEnd = titleEnd
|
||||
titleEnd = i
|
||||
}
|
||||
}
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
// The first bit of this logic is the same as Parser.listItem, but the rest
|
||||
// is much simpler. This function simply finds the entire block and shifts it
|
||||
// over by one tab if it is indeed a block (just returns the line if it's not).
|
||||
// blockEnd is the end of the section in the input buffer, and contents is the
|
||||
// extracted text that was shifted over one tab. It will need to be rendered at
|
||||
// the end of the document.
|
||||
func scanFootnote(p *Parser, data []byte, i, indentSize int) (blockStart, blockEnd int, contents []byte, hasBlock bool) {
|
||||
if i == 0 || len(data) == 0 {
|
||||
return
|
||||
}
|
||||
|
||||
// skip leading whitespace on first line
|
||||
for i < len(data) && data[i] == ' ' {
|
||||
i++
|
||||
}
|
||||
|
||||
blockStart = i
|
||||
|
||||
// find the end of the line
|
||||
blockEnd = i
|
||||
for i < len(data) && data[i-1] != '\n' {
|
||||
i++
|
||||
}
|
||||
|
||||
// get working buffer
|
||||
var raw bytes.Buffer
|
||||
|
||||
// put the first line into the working buffer
|
||||
raw.Write(data[blockEnd:i])
|
||||
blockEnd = i
|
||||
|
||||
// process the following lines
|
||||
containsBlankLine := false
|
||||
|
||||
gatherLines:
|
||||
for blockEnd < len(data) {
|
||||
i++
|
||||
|
||||
// find the end of this line
|
||||
for i < len(data) && 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[blockEnd:i]) > 0 {
|
||||
containsBlankLine = true
|
||||
blockEnd = i
|
||||
continue
|
||||
}
|
||||
|
||||
n := 0
|
||||
if n = isIndented(data[blockEnd:i], indentSize); n == 0 {
|
||||
// this is the end of the block.
|
||||
// we don't want to include this last line in the index.
|
||||
break gatherLines
|
||||
}
|
||||
|
||||
// if there were blank lines before this one, insert a new one now
|
||||
if containsBlankLine {
|
||||
raw.WriteByte('\n')
|
||||
containsBlankLine = false
|
||||
}
|
||||
|
||||
// get rid of that first tab, write to buffer
|
||||
raw.Write(data[blockEnd+n : i])
|
||||
hasBlock = true
|
||||
|
||||
blockEnd = i
|
||||
}
|
||||
|
||||
if data[blockEnd-1] != '\n' {
|
||||
raw.WriteByte('\n')
|
||||
}
|
||||
|
||||
contents = raw.Bytes()
|
||||
|
||||
return
|
||||
}
|
||||
|
||||
//
|
||||
//
|
||||
// Miscellaneous helper functions
|
||||
//
|
||||
//
|
||||
|
||||
// Test if a character is a punctuation symbol.
|
||||
// Taken from a private function in regexp in the stdlib.
|
||||
func ispunct(c byte) bool {
|
||||
for _, r := range []byte("!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~") {
|
||||
if c == r {
|
||||
return true
|
||||
}
|
||||
}
|
||||
return false
|
||||
}
|
||||
|
||||
// Test if a character is a whitespace character.
|
||||
func isspace(c byte) bool {
|
||||
return c == ' ' || c == '\t' || c == '\n' || c == '\r' || c == '\f' || c == '\v'
|
||||
}
|
||||
|
||||
// Test if a character is letter.
|
||||
func isletter(c byte) bool {
|
||||
return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
|
||||
}
|
||||
|
||||
// Test if a character is a letter or a digit.
|
||||
// TODO: check when this is looking for ASCII alnum and when it should use unicode
|
||||
func isalnum(c byte) bool {
|
||||
return (c >= '0' && c <= '9') || isletter(c)
|
||||
}
|
||||
|
||||
// Replace tab characters with spaces, aligning to the next TAB_SIZE column.
|
||||
// always ends output with a newline
|
||||
func expandTabs(out *bytes.Buffer, line []byte, tabSize int) {
|
||||
// first, check for common cases: no tabs, or only tabs at beginning of line
|
||||
i, prefix := 0, 0
|
||||
slowcase := false
|
||||
for i = 0; i < len(line); i++ {
|
||||
if line[i] == '\t' {
|
||||
if prefix == i {
|
||||
prefix++
|
||||
} else {
|
||||
slowcase = true
|
||||
break
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// no need to decode runes if all tabs are at the beginning of the line
|
||||
if !slowcase {
|
||||
for i = 0; i < prefix*tabSize; i++ {
|
||||
out.WriteByte(' ')
|
||||
}
|
||||
out.Write(line[prefix:])
|
||||
return
|
||||
}
|
||||
|
||||
// the slow case: we need to count runes to figure out how
|
||||
// many spaces to insert for each tab
|
||||
column := 0
|
||||
i = 0
|
||||
for i < len(line) {
|
||||
start := i
|
||||
for i < len(line) && line[i] != '\t' {
|
||||
_, size := utf8.DecodeRune(line[i:])
|
||||
i += size
|
||||
column++
|
||||
}
|
||||
|
||||
if i > start {
|
||||
out.Write(line[start:i])
|
||||
}
|
||||
|
||||
if i >= len(line) {
|
||||
break
|
||||
}
|
||||
|
||||
for {
|
||||
out.WriteByte(' ')
|
||||
column++
|
||||
if column%tabSize == 0 {
|
||||
break
|
||||
}
|
||||
}
|
||||
|
||||
i++
|
||||
}
|
||||
}
|
||||
|
||||
// Find if a line counts as indented or not.
|
||||
// Returns number of characters the indent is (0 = not indented).
|
||||
func isIndented(data []byte, indentSize int) int {
|
||||
if len(data) == 0 {
|
||||
return 0
|
||||
}
|
||||
if data[0] == '\t' {
|
||||
return 1
|
||||
}
|
||||
if len(data) < indentSize {
|
||||
return 0
|
||||
}
|
||||
for i := 0; i < indentSize; i++ {
|
||||
if data[i] != ' ' {
|
||||
return 0
|
||||
}
|
||||
}
|
||||
return indentSize
|
||||
}
|
||||
|
||||
// Create a url-safe slug for fragments
|
||||
func slugify(in []byte) []byte {
|
||||
if len(in) == 0 {
|
||||
return in
|
||||
}
|
||||
out := make([]byte, 0, len(in))
|
||||
sym := false
|
||||
|
||||
for _, ch := range in {
|
||||
if isalnum(ch) {
|
||||
sym = false
|
||||
out = append(out, ch)
|
||||
} else if sym {
|
||||
continue
|
||||
} else {
|
||||
out = append(out, '-')
|
||||
sym = true
|
||||
}
|
||||
}
|
||||
var a, b int
|
||||
var ch byte
|
||||
for a, ch = range out {
|
||||
if ch != '-' {
|
||||
break
|
||||
}
|
||||
}
|
||||
for b = len(out) - 1; b > 0; b-- {
|
||||
if out[b] != '-' {
|
||||
break
|
||||
}
|
||||
}
|
||||
return out[a : b+1]
|
||||
}
|
||||
Loading…
Reference in New Issue