rst

Nim-flavored reStructuredText and Markdown

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This module implements a reStructuredText (RST) parser. A large subset is implemented with some limitations and Nim-specific features. A few extra features of the Markdown syntax are also supported.

Nim can output the result to HTML [1] or Latex [2].

[1]
  commands nim doc for *.nim files and nim rst2html for *.rst files
[2]
  commands nim doc2tex for *.nim and nim rst2tex for *.rst.

If you are new to RST please consider reading the following:

  1. a short quick introduction
  2. an RST reference: a comprehensive cheatsheet for RST
  3. a more formal 50-page RST specification.

Features

Supported standard RST features:

  • body elements
    • sections
    • transitions
    • paragraphs
    • bullet lists using +, *, -
    • enumerated lists using arabic numerals or alphabet characters: 1. ... 2. ... or a. ... b. ... or A. ... B. ...
    • footnotes (including manually numbered, auto-numbered, auto-numbered with label, and auto-symbol footnotes) and citations
    • definition lists
    • field lists
    • option lists
    • indented literal blocks
    • simple tables
    • directives (see official documentation in RST directives list):
      • image, figure for including images and videos
      • code
      • contents (table of contents), container, raw
      • include
      • admonitions: "attention", "caution", "danger", "error", "hint", "important", "note", "tip", "warning", "admonition"
      • substitution definitions: replace and image
    • comments
  • inline markup
    • emphasis, strong emphasis, inline literals, hyperlink references (including embedded URI), substitution references, standalone hyperlinks, internal links (inline and outline)
    • `interpreted text` with roles :literal:, :strong:, emphasis, :sub:/:subscript:, :sup:/:superscript: (see RST roles list for description).
    • inline internal targets

Additional Nim-specific features:

  • directives: code-block [cmp:Sphinx], title, index [cmp:Sphinx]
  • predefined roles
    • :nim: (default), :c: (C programming language), :python:, :yaml:, :java:, :csharp (C#). That is every language that highlite supports. They turn on appropriate syntax highlighting in inline code.
      Note: default role for Nim files is :nim:, for *.rst it's currently :literal:.
    • generic command line highlighting roles:
      • :cmd: for commands and common shells syntax
      • :console: the same for interactive sessions (commands should be prepended by $)
      • :program: for executable names [cmp:Sphinx] (one can just use :cmd: on single word)
      • :option: for command line options [cmp:Sphinx]
    • :tok:, a role for highlighting of programming language tokens
  • triple emphasis (bold and italic) using ***
  • :idx: role for `interpreted text` to include the link to this text into an index (example: Nim index).

  • double slash // in option lists serves as a prefix for any option that starts from a word (without any leading symbols like -, --, /):

    //compile   compile the project
//doc       generate documentation

    Here the dummy // will disappear, while options compile and doc will be left in the final document.

[cmp:Sphinx]
  similar but different from the directives of Python Sphinx directives and Sphinx roles extensions

Optional additional features, turned on by options: RstParseOption in rstParse proc:

  • emoji / smiley symbols
  • Markdown tables
  • Markdown code blocks
  • Markdown links
  • Markdown headlines
  • using 1 as auto-enumerator in enumerated lists like RST # (auto-enumerator 1 can not be used with # in the same list)
Note: By default Nim has roSupportMarkdown and roSupportRawDirective turned on.
Warning: Using Nim-specific features can cause other RST implementations to fail on your document.

Idiosyncrasies

Currently we do not aim at 100% Markdown or RST compatibility in inline markup recognition rules because that would provide very little user value. This parser has 2 modes for inline markup:

  1. Markdown-like mode which is enabled by roPreferMarkdown option (turned on by default).
    Note: RST features like directives are still turned on
  2. Compatibility mode which is RST rules.
Note: in both modes the parser interpretes text between single
backticks (code) identically:
backslash does not escape; the only exception: \ folowed by ` does escape so that we can always input a single backtick ` in inline code. However that makes impossible to input code with \ at the end in single backticks, one must use double backticks:
`\`   -- WRONG
``\`` -- GOOD
So single backticks can always be input: `\`` will turn to ` code

Limitations

  • no Unicode support in character width calculations
  • body elements
    • no roman numerals in enumerated lists
    • no quoted literal blocks
    • no doctest blocks
    • no grid tables
    • some directives are missing (check official RST directives list): parsed-literal, sidebar, topic, math, rubric, epigraph, highlights, pull-quote, compound, table, csv-table, list-table, section-numbering, header, footer, meta, class
      • no role directives and no custom interpreted text roles
      • some standard roles are not supported (check RST roles list)
      • no generic admonition support
  • inline markup
    • no simple-inline-markup
    • no embedded aliases

Usage

See Nim DocGen Tools Guide for the details about nim doc, nim rst2html and nim rst2tex commands.

See packages/docutils/rstgen module to know how to generate HTML or Latex strings to embed them into your documents.

Types

EParseError = object of ValueError
  Source   Edit 
FindFileHandler = proc (filename: string): string {.closure, ...gcsafe.}
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MsgClass = enum
  mcHint = "Hint", mcWarning = "Warning", mcError = "Error"
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MsgHandler = proc (filename: string; line, col: int; msgKind: MsgKind;
                   arg: string) {.closure, ...gcsafe.}
what to do in case of an error   Source   Edit 
MsgKind = enum
  meCannotOpenFile = "cannot open \'$1\'", meExpected = "\'$1\' expected",
  meGridTableNotImplemented = "grid table is not implemented",
  meMarkdownIllformedTable = "illformed delimiter row of a Markdown table",
  meNewSectionExpected = "new section expected $1",
  meGeneralParseError = "general parse error",
  meInvalidDirective = "invalid directive: \'$1\'",
  meInvalidField = "invalid field: $1",
  meFootnoteMismatch = "mismatch in number of footnotes and their refs: $1",
  mwRedefinitionOfLabel = "redefinition of label \'$1\'",
  mwUnknownSubstitution = "unknown substitution \'$1\'",
  mwBrokenLink = "broken link \'$1\'",
  mwUnsupportedLanguage = "language \'$1\' not supported",
  mwUnsupportedField = "field \'$1\' not supported",
  mwRstStyle = "RST style: $1"
the possible messages   Source   Edit 
PRstSharedState = ref RstSharedState
  Source   Edit 
RstFileTable = object
  filenameToIdx*: Table[string, FileIndex]
  idxToFilename*: seq[string]
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RstParseOption = enum
  roSupportSmilies,         ## make the RST parser support smilies like ``:)``
  roSupportRawDirective,    ## support the ``raw`` directive (don't support
                             ## it for sandboxing)
  roSupportMarkdown,        ## support additional features of Markdown
  roPreferMarkdown,         ## parse as Markdown (keeping RST as "extension"
                             ## to Markdown) -- implies `roSupportMarkdown`
  roNimFile                  ## set for Nim files where default interpreted
                             ## text role should be :nim:
options for the RST parser   Source   Edit

Consts

ColRstInit = 0
Initial column number for standalone RST text (Nim global reporting adds ColOffset=1)   Source   Edit 
ColRstOffset = 1
1: a replica of ColOffset for internal use   Source   Edit 
LineRstInit = 1
Initial line number for standalone RST text   Source   Edit

Procs

proc addNodes(n: PRstNode): string {....raises: [], tags: [].}
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proc defaultFindFile(filename: string): string {....raises: [],
    tags: [ReadDirEffect].}
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proc defaultMsgHandler(filename: string; line, col: int; msgkind: MsgKind;
                       arg: string) {....raises: [ValueError, EParseError, IOError],
                                      tags: [WriteIOEffect].}
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proc getArgument(n: PRstNode): string {....raises: [], tags: [].}
  Source   Edit 
proc getFieldValue(n: PRstNode): string {....raises: [], tags: [].}

Returns the value of a specific rnField node.

This proc will assert if the node is not of the expected type. The empty string will be returned as a minimum. Any value in the rst will be stripped form leading/trailing whitespace.

  Source   Edit 
proc getFieldValue(n: PRstNode; fieldname: string): string {....raises: [],
    tags: [].}
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proc newRstSharedState(options: RstParseOptions; filename: string;
                       findFile: FindFileHandler; msgHandler: MsgHandler): PRstSharedState {.
    ...raises: [], tags: [].}
  Source   Edit 
proc preparePass2(s: PRstSharedState; mainNode: PRstNode) {.
    ...raises: [Exception, ValueError], tags: [RootEffect].}
Records titles in node mainNode and orders footnotes.   Source   Edit 
proc resolveSubs(s: PRstSharedState; n: PRstNode): PRstNode {.
    ...raises: [ValueError, Exception], tags: [ReadEnvEffect, RootEffect].}
Makes pass 2 of RST parsing. Resolves substitutions and anchor aliases, groups footnotes. Takes input node n and returns the same node with recursive substitutions in n.sons to result.   Source   Edit 
proc rstMessage(filenames: RstFileTable; f: MsgHandler; info: TLineInfo;
                msgKind: MsgKind; arg: string) {....raises: [ValueError], tags: [].}
Print warnings using info, i.e. in 2nd-pass warnings for footnotes/substitutions/references or from rstgen.nim.   Source   Edit 
proc rstnodeToRefname(n: PRstNode): string {....raises: [], tags: [].}
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proc rstParse(text, filename: string; line, column: int;
              options: RstParseOptions; findFile: FindFileHandler = nil;
              msgHandler: MsgHandler = nil): tuple[node: PRstNode,
    filenames: RstFileTable, hasToc: bool] {....raises: [Exception, ValueError],
    tags: [RootEffect, ReadEnvEffect].}
Parses the whole text. The result is ready for rstgen.renderRstToOut, note that 2nd tuple element should be fed to initRstGenerator   Source   Edit 
proc rstParsePass1(fragment: string; line, column: int;
                   sharedState: PRstSharedState): PRstNode {.
    ...raises: [Exception, ValueError], tags: [RootEffect].}
Parses an RST fragment. The result should be further processed by preparePass2 and resolveSubs (which is pass 2).   Source   Edit 
proc whichMsgClass(k: MsgKind): MsgClass {....raises: [], tags: [].}
returns which message class k belongs to.   Source   Edit

Made with Nim. Generated: 2024-12-20 00:00:00 UTC