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diff --git a/doc/docs/quickstart.rst b/doc/docs/quickstart.rst new file mode 100644 index 00000000..dba7698a --- /dev/null +++ b/doc/docs/quickstart.rst @@ -0,0 +1,205 @@ +.. -*- mode: rst -*- + +=========================== +Introduction and Quickstart +=========================== + + +Welcome to Pygments! This document explains the basic concepts and terms and +gives a few examples of how to use the library. + + +Architecture +============ + +There are four types of components that work together highlighting a piece of +code: + +* A **lexer** splits the source into tokens, fragments of the source that + have a token type that determines what the text represents semantically + (e.g., keyword, string, or comment). There is a lexer for every language + or markup format that Pygments supports. +* The token stream can be piped through **filters**, which usually modify + the token types or text fragments, e.g. uppercasing all keywords. +* A **formatter** then takes the token stream and writes it to an output + file, in a format such as HTML, LaTeX or RTF. +* While writing the output, a **style** determines how to highlight all the + different token types. It maps them to attributes like "red and bold". + + +Example +======= + +Here is a small example for highlighting Python code: + +.. sourcecode:: python + + from pygments import highlight + from pygments.lexers import PythonLexer + from pygments.formatters import HtmlFormatter + + code = 'print "Hello World"' + print highlight(code, PythonLexer(), HtmlFormatter()) + +which prints something like this: + +.. sourcecode:: html + + <div class="highlight"> + <pre><span class="k">print</span> <span class="s">"Hello World"</span></pre> + </div> + +As you can see, Pygments uses CSS classes (by default, but you can change that) +instead of inline styles in order to avoid outputting redundant style information over +and over. A CSS stylesheet that contains all CSS classes possibly used in the output +can be produced by: + +.. sourcecode:: python + + print HtmlFormatter().get_style_defs('.highlight') + +The argument to :func:`get_style_defs` is used as an additional CSS selector: +the output may look like this: + +.. sourcecode:: css + + .highlight .k { color: #AA22FF; font-weight: bold } + .highlight .s { color: #BB4444 } + ... + + +Options +======= + +The :func:`highlight()` function supports a fourth argument called *outfile*, it +must be a file object if given. The formatted output will then be written to +this file instead of being returned as a string. + +Lexers and formatters both support options. They are given to them as keyword +arguments either to the class or to the lookup method: + +.. sourcecode:: python + + from pygments import highlight + from pygments.lexers import get_lexer_by_name + from pygments.formatters import HtmlFormatter + + lexer = get_lexer_by_name("python", stripall=True) + formatter = HtmlFormatter(linenos=True, cssclass="source") + result = highlight(code, lexer, formatter) + +This makes the lexer strip all leading and trailing whitespace from the input +(`stripall` option), lets the formatter output line numbers (`linenos` option), +and sets the wrapping ``<div>``'s class to ``source`` (instead of +``highlight``). + +Important options include: + +`encoding` : for lexers and formatters + Since Pygments uses Unicode strings internally, this determines which + encoding will be used to convert to or from byte strings. +`style` : for formatters + The name of the style to use when writing the output. + + +For an overview of builtin lexers and formatters and their options, visit the +:doc:`lexer <lexers>` and :doc:`formatters <formatters>` lists. + +For a documentation on filters, see :doc:`this page <filters>`. + + +Lexer and formatter lookup +========================== + +If you want to lookup a built-in lexer by its alias or a filename, you can use +one of the following methods: + +.. sourcecode:: pycon + + >>> from pygments.lexers import (get_lexer_by_name, + ... get_lexer_for_filename, get_lexer_for_mimetype) + + >>> get_lexer_by_name('python') + <pygments.lexers.PythonLexer> + + >>> get_lexer_for_filename('spam.rb') + <pygments.lexers.RubyLexer> + + >>> get_lexer_for_mimetype('text/x-perl') + <pygments.lexers.PerlLexer> + +All these functions accept keyword arguments; they will be passed to the lexer +as options. + +A similar API is available for formatters: use :func:`.get_formatter_by_name()` +and :func:`.get_formatter_for_filename()` from the :mod:`pygments.formatters` +module for this purpose. + + +Guessing lexers +=============== + +If you don't know the content of the file, or you want to highlight a file +whose extension is ambiguous, such as ``.html`` (which could contain plain HTML +or some template tags), use these functions: + +.. sourcecode:: pycon + + >>> from pygments.lexers import guess_lexer, guess_lexer_for_filename + + >>> guess_lexer('#!/usr/bin/python\nprint "Hello World!"') + <pygments.lexers.PythonLexer> + + >>> guess_lexer_for_filename('test.py', 'print "Hello World!"') + <pygments.lexers.PythonLexer> + +:func:`.guess_lexer()` passes the given content to the lexer classes' +:meth:`analyse_text()` method and returns the one for which it returns the +highest number. + +All lexers have two different filename pattern lists: the primary and the +secondary one. The :func:`.get_lexer_for_filename()` function only uses the +primary list, whose entries are supposed to be unique among all lexers. +:func:`.guess_lexer_for_filename()`, however, will first loop through all lexers +and look at the primary and secondary filename patterns if the filename matches. +If only one lexer matches, it is returned, else the guessing mechanism of +:func:`.guess_lexer()` is used with the matching lexers. + +As usual, keyword arguments to these functions are given to the created lexer +as options. + + +Command line usage +================== + +You can use Pygments from the command line, using the :program:`pygmentize` +script:: + + $ pygmentize test.py + +will highlight the Python file test.py using ANSI escape sequences +(a.k.a. terminal colors) and print the result to standard output. + +To output HTML, use the ``-f`` option:: + + $ pygmentize -f html -o test.html test.py + +to write an HTML-highlighted version of test.py to the file test.html. +Note that it will only be a snippet of HTML, if you want a full HTML document, +use the "full" option:: + + $ pygmentize -f html -O full -o test.html test.py + +This will produce a full HTML document with included stylesheet. + +A style can be selected with ``-O style=<name>``. + +If you need a stylesheet for an existing HTML file using Pygments CSS classes, +it can be created with:: + + $ pygmentize -S default -f html > style.css + +where ``default`` is the style name. + +More options and tricks and be found in the :doc:`command line reference +<cmdline>`. |