New sandbox project for development of a code-block directive

git-svn-id: http://svn.code.sf.net/p/docutils/code/trunk@5229 929543f6-e4f2-0310-98a6-ba3bd3dd1d04

1 files changed, 177 insertions, 0 deletions

diff --git a/sandbox/code-block-directive/pygments_code_block_directive.py b/sandbox/code-block-directive/pygments_code_block_directive.py
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+++ b/sandbox/code-block-directive/pygments_code_block_directive.py
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+#!/usr/bin/python
+
+# :Author: a Pygments author|contributor; Felix Wiemann; Guenter Milde
+# :Date: $Date$
+# :Copyright: This module has been placed in the public domain.
+# 
+# This is a merge of `Using Pygments in ReST documents`_ from the pygments_
+# documentation, and a `proof of concept`_ by Felix Wiemann.
+# 
+# ========== ===========================================================
+# 2007-06-01 Removed redundancy from class values.
+# 2007-06-04 Merge of successive tokens of same type
+#            (code taken from pygments.formatters.others).
+# 2007-06-05 Separate docutils formatter script
+#            Use pygments' CSS class names (like the html formatter)
+#            allowing the use of pygments-produced style sheets.
+# 2007-06-07 Re-include the formatting of the parsed tokens 
+#            (class DocutilsInterface)
+# 2007-06-08 Failsave implementation (fallback if pygments not found)
+# ========== ===========================================================
+# 
+# ::
+
+"""Define and register a code-block directive using pygments
+"""
+
+# Requirements
+# ------------
+# ::
+
+from docutils import nodes
+from docutils.parsers.rst import directives
+try:
+    import pygments
+    from pygments.lexers import get_lexer_by_name
+    from pygments.formatters.html import _get_ttype_class
+except ImportError:
+    pass
+
+
+
+# Customisation
+# -------------
+# 
+# Do not insert inline nodes for the following tokens.
+# (You could add e.g. Token.Punctuation like ``['', 'p']``.) ::
+
+unstyled_tokens = ['']
+
+# DocutilsInterface
+# -----------------
+# 
+# This interface class combines code from
+# pygments.formatters.html and pygments.formatters.others.
+# 
+# It does not require anything of docutils and could alse become a part of
+# pygments::
+
+class DocutilsInterface(object):
+    """Parse `code` string and yield "classified" tokens.
+    
+    Arguments
+    
+      code     -- string of source code to parse
+      language -- formal language the code is written in.
+    
+    Merge subsequent tokens of the same token-type. 
+    
+    Yields the tokens as ``(ttype_class, value)`` tuples, 
+    where ttype_class is taken from pygments.token.STANDARD_TYPES and 
+    corresponds to the class argument used in pygments html output.
+
+    """
+
+    def __init__(self, code, language):
+        self.code = code
+        self.language = language
+        
+    def lex(self):
+        # Get lexer for language (use text as fallback)
+        try:
+            lexer = get_lexer_by_name(self.language)
+        except ValueError:
+            # info: "no pygments lexer for %s, using 'text'"%self.language
+            lexer = get_lexer_by_name('text')
+        return pygments.lex(self.code, lexer)
+        
+            
+    def join(self, tokens):
+        """join subsequent tokens of same token-type
+        """
+        tokens = iter(tokens)
+        (lasttype, lastval) = tokens.next()
+        for ttype, value in tokens:
+            if ttype is lasttype:
+                lastval += value
+            else:
+                yield(lasttype, lastval)
+                (lasttype, lastval) = (ttype, value)
+        yield(lasttype, lastval)
+
+    def __iter__(self):
+        """parse code string and yield "clasified" tokens
+        """
+        try:
+            tokens = self.lex()
+        except IOError:
+            print "INFO: Pygments lexer not found, using fallback"
+            # TODO: write message to INFO 
+            yield ('', self.code)
+            return
+
+        for ttype, value in self.join(tokens):
+            yield (_get_ttype_class(ttype), value)
+
+
+
+# code_block_directive
+# --------------------
+# ::
+
+def code_block_directive(name, arguments, options, content, lineno,
+                       content_offset, block_text, state, state_machine):
+    """parse and classify content of a code_block
+    """
+    language = arguments[0]
+    # create a literal block element and set class argument
+    code_block = nodes.literal_block(classes=["code-block", language])
+    
+    # parse content with pygments and add to code_block element
+    for cls, value in DocutilsInterface(u'\n'.join(content), language):
+        if cls in unstyled_tokens:
+            # insert as Text to decrease the verbosity of the output.
+            code_block += nodes.Text(value, value)
+        else:
+            code_block += nodes.inline(value, value, classes=[cls])
+
+    return [code_block]
+
+
+# Register Directive
+# ------------------
+# ::
+
+code_block_directive.arguments = (1, 0, 1)
+code_block_directive.content = 1
+directives.register_directive('code-block', code_block_directive)
+
+# .. _doctutils: http://docutils.sf.net/
+# .. _pygments: http://pygments.org/
+# .. _Using Pygments in ReST documents: http://pygments.org/docs/rstdirective/
+# .. _proof of concept:
+#      http://article.gmane.org/gmane.text.docutils.user/3689
+# 
+# Test output
+# -----------
+# 
+# If called from the command line, call the docutils publisher to render the
+# input::
+
+if __name__ == '__main__':
+    from docutils.core import publish_cmdline, default_description
+    description = "code-block directive test output" + default_description
+    try:
+        import locale
+        locale.setlocale(locale.LC_ALL, '')
+    except:
+        pass
+    # Uncomment the desired output format:
+    publish_cmdline(writer_name='pseudoxml', description=description)
+    # publish_cmdline(writer_name='xml', description=description)
+    # publish_cmdline(writer_name='html', description=description)
+    # publish_cmdline(writer_name='latex', description=description)
+    # publish_cmdline(writer_name='newlatex2e', description=description)
+    
+
+