From baedd3b2366868dbf20e59d9290ee2f755d9740b Mon Sep 17 00:00:00 2001
From: Louis <spalax@gresille.org>
Date: Tue, 30 Sep 2014 23:41:33 +0200
Subject: [PATCH] [WIP] LaTeX files are parsed again

---
 patacrep/build.py          |  17 ++--
 patacrep/content/sorted.py |   2 +-
 patacrep/index.py          |   4 +-
 patacrep/latex/__init__.py |  27 +++---
 patacrep/latex/ast.py      |  49 ++++++++++
 patacrep/latex/detex.py    | 110 +++++++++++++++++++++
 patacrep/latex/lexer.py    | 124 ++++++++++++++++++++++++
 patacrep/latex/parsetab.py |  72 ++++++++++++++
 patacrep/latex/syntax.py   | 194 +++++++++++++++++++++++++++++++++++++
 patacrep/latex/testing.py  |  50 ++++++++++
 patacrep/songs.py          |  17 ++--
 11 files changed, 632 insertions(+), 34 deletions(-)
 create mode 100644 patacrep/latex/ast.py
 create mode 100644 patacrep/latex/detex.py
 create mode 100644 patacrep/latex/lexer.py
 create mode 100644 patacrep/latex/parsetab.py
 create mode 100644 patacrep/latex/syntax.py
 create mode 100644 patacrep/latex/testing.py

diff --git a/patacrep/build.py b/patacrep/build.py
index 9f79bb6a..212305ca 100644
--- a/patacrep/build.py
+++ b/patacrep/build.py
@@ -50,7 +50,6 @@ class Songbook(object):
         super(Songbook, self).__init__()
         self.config = raw_songbook
         self.basename = basename
-        self.contentlist = []
         # Some special keys have their value processed.
         self._set_datadir()
 
@@ -86,7 +85,7 @@ class Songbook(object):
         - output: a file object, in which the file will be written.
         """
         # Updating configuration
-        config = DEFAULT_CONFIG
+        config = DEFAULT_CONFIG.copy()
         config.update(self.config)
         renderer = TexRenderer(
                 config['template'],
@@ -100,18 +99,16 @@ class Songbook(object):
                 copy.deepcopy(config['authwords'])
                 )
 
-        self.config = config
         # Configuration set
 
-        self.contentlist = content.process_content(
-                self.config.get('content', []),
-                self.config,
+        config['render_content'] = content.render_content
+        config['content'] = content.process_content(
+                config.get('content', []),
+                config,
                 )
-        self.config['render_content'] = content.render_content
-        self.config['content'] = self.contentlist
-        self.config['filename'] = output.name[:-4]
+        config['filename'] = output.name[:-4]
 
-        renderer.render_tex(output, self.config)
+        renderer.render_tex(output, config)
 
 
 class SongbookBuilder(object):
diff --git a/patacrep/content/sorted.py b/patacrep/content/sorted.py
index 651bd07e..f95065d6 100755
--- a/patacrep/content/sorted.py
+++ b/patacrep/content/sorted.py
@@ -55,7 +55,7 @@ def key_generator(sort):
                 field = song.authors
             else:
                 try:
-                    field = song.args[key]
+                    field = song.data[key]
                 except KeyError:
                     LOGGER.debug(
                             "Ignoring unknown key '{}' for song {}.".format(
diff --git a/patacrep/index.py b/patacrep/index.py
index ac927569..c715918a 100644
--- a/patacrep/index.py
+++ b/patacrep/index.py
@@ -13,7 +13,7 @@ import re
 
 from patacrep import authors
 from patacrep import encoding
-from patacrep.latex import latex2unicode
+from patacrep.latex import tex2plain
 
 EOL = "\n"
 
@@ -113,7 +113,7 @@ class Index(object):
         if not key in self.data[first]:
             self.data[first][key] = {
                     'sortingkey': [
-                        unidecode.unidecode(latex2unicode(item)).lower()
+                        unidecode.unidecode(tex2plain(item)).lower()
                         for item in key
                         ],
                     'entries': [],
diff --git a/patacrep/latex/__init__.py b/patacrep/latex/__init__.py
index 08d1805f..b0826e6e 100644
--- a/patacrep/latex/__init__.py
+++ b/patacrep/latex/__init__.py
@@ -1,23 +1,26 @@
 # -*- coding: utf-8 -*-
 
+from patacrep.latex.syntax import tex2plain as syntax_tex2plain
+from patacrep.latex.syntax import parsesong as syntax_parsesong
+from patacrep.latex.detex import detex
+from patacrep import encoding
+
 """Very simple LaTeX parser"""
 
-def latex2unicode(string):
-    """Convert LaTeX string to unicode"""
-    return "TODO"
+def tex2plain(string):
+    """Render LaTeX string
+
+    Very few commands (mostly diacritics) are interpreted.
+    """
+    return syntax_tex2plain(string)
 
-def parsetex(path):
+def parsesong(path):
     """Return a dictonary of data read from the latex file `path`.
 
     This file is a drop in replacement for an old function. Elle ne devrait pas
     apparaitre telle quelle dans la version finale, une fois que
     https://github.com/patacrep/patacrep/issues/64 aura été pris en compte.
-
-    TODO
     """
-    return {
-            'titles': ["TODO"],
-            'args': {},
-            'languages': ['french', 'english', 'portuguese', 'spanish'],
-            }
-
+    data = syntax_parsesong(encoding.open_read(path).read(), path)
+    data['@path'] = path
+    return data
diff --git a/patacrep/latex/ast.py b/patacrep/latex/ast.py
new file mode 100644
index 00000000..1f181172
--- /dev/null
+++ b/patacrep/latex/ast.py
@@ -0,0 +1,49 @@
+class AST:
+
+    metadata = None
+
+    @classmethod
+    def init_metadata(cls):
+        cls.metadata = {
+                '@languages': set(),
+                }
+
+class Expression(AST):
+
+    def __init__(self, value):
+        super().__init__()
+        self.content = [value]
+
+    def prepend(self, value):
+        if value is not None:
+            self.content.insert(0, value)
+        return self
+
+    def __str__(self):
+        return "".join([str(item) for item in self.content])
+
+class Command(AST):
+
+    def __init__(self, name, optional, mandatory):
+        self.name = name
+        self.mandatory = mandatory
+        self.optional = optional
+
+        if name == r'\selectlanguage':
+            self.metadata['@languages'] |= set(self.mandatory)
+
+    def __str__(self):
+        if self.name in [r'\emph']:
+            return str(self.mandatory[0])
+        return "{}{}{}".format(
+                self.name,
+                "".join(["[{}]".format(item) for item in self.optional]),
+                "".join(["{{{}}}".format(item) for item in self.mandatory]),
+                )
+
+
+class BeginSong(AST):
+
+    def __init__(self, titles, arguments):
+        self.titles = titles
+        self.arguments = arguments
diff --git a/patacrep/latex/detex.py b/patacrep/latex/detex.py
new file mode 100644
index 00000000..cb9f277f
--- /dev/null
+++ b/patacrep/latex/detex.py
@@ -0,0 +1,110 @@
+MATCH = [
+    # Diacritics: a
+    (r"\'a", "á"),
+    (r"\'A", "Á"),
+    (r"\`a", "à"),
+    (r"\`A", "À"),
+    (r"\^a", "â"),
+    (r"\^A", "Â"),
+    (r"\"a", "ä"),
+    (r"\"A", "Ä"),
+
+    # Diacritics: e
+    (r"\'e", "é"),
+    (r"\'E", "É"),
+    (r"\`e", "è"),
+    (r"\`E", "È"),
+    (r"\^e", "ê"),
+    (r"\^E", "Ê"),
+    (r"\"e", "ë"),
+    (r"\"E", "Ë"),
+
+    # Diacritics: i
+    (r"\'i", "í"),
+    (r"\'I", "Í"),
+    (r"\`i", "ì"),
+    (r"\`I", "Ì"),
+    (r"\^i", "î"),
+    (r"\^I", "Î"),
+    (r"\"i", "ï"),
+    (r"\"I", "Ï"),
+    (r"\'\i", "í"),
+    (r"\'\I", "Í"),
+    (r"\`\i", "ì"),
+    (r"\`\I", "Ì"),
+    (r"\^\i", "î"),
+    (r"\^\I", "Î"),
+    (r"\"\i", "ï"),
+    (r"\"\I", "Ï"),
+
+    # Diacritics: o
+    (r"\'o", "ó"),
+    (r"\'O", "Ó"),
+    (r"\`o", "ò"),
+    (r"\`O", "Ò"),
+    (r"\^o", "ô"),
+    (r"\^O", "Ô"),
+    (r"\"o", "ö"),
+    (r"\"O", "Ö"),
+
+    # Diacritics: u
+    (r"\'u", "ú"),
+    (r"\'U", "Ú"),
+    (r"\`u", "ù"),
+    (r"\`U", "Ù"),
+    (r"\^u", "û"),
+    (r"\^U", "Û"),
+    (r"\"u", "ü"),
+    (r"\"U", "Ü"),
+
+    # Cedille
+    (r"\c c", "ç"),
+    (r"\c C", "Ç"),
+
+    # œ, æ
+    (r"\oe", "œ"),
+    (r"\OE", "Œ"),
+    (r"\ae", "æ"),
+    (r"\AE", "Æ"),
+
+    # Spaces
+    (r"\ ", " "),
+    (r"\,", " "),
+    (r"\~", " "),
+
+    # IeC
+    (r"\IeC ", ""),
+
+    # Miscallenous
+    (r"\dots", "…"),
+    (r"\%", "%"),
+    (r"\&", "&"),
+    (r"\_", "_"),
+
+    ]
+
+
+def detex(arg):
+    if isinstance(arg, dict):
+        return dict([
+            (key, detex(value))
+            for (key, value)
+            in arg.items()
+            ])
+    elif isinstance(arg, list):
+        return [
+                detex(item)
+                for item
+                in arg
+                ]
+    elif isinstance(arg, set):
+        return set(detex(list(arg)))
+    elif isinstance(arg, str):
+        string = arg
+        for (latex, plain) in MATCH:
+            string = string.replace(latex, plain)
+        if '\\' in string:
+            print("WARNING: Remaining command in string '{}'.".format(string))
+        return string.strip()
+    else:
+        return detex(str(arg))
diff --git a/patacrep/latex/lexer.py b/patacrep/latex/lexer.py
new file mode 100644
index 00000000..199d6f9c
--- /dev/null
+++ b/patacrep/latex/lexer.py
@@ -0,0 +1,124 @@
+import ply.lex as lex
+
+tokens = (
+   'LBRACKET',
+   'RBRACKET',
+   'LBRACE',
+   'RBRACE',
+   'COMMAND',
+   'NEWLINE',
+   'COMMA',
+   'EQUAL',
+   'CHARACTER',
+   'SPACE',
+   'BEGINSONG',
+   'SONG_LTITLE',
+   'SONG_RTITLE',
+   'SONG_LOPTIONS',
+   'SONG_ROPTIONS',
+)
+
+class SimpleLexer:
+
+    tokens = tokens
+
+    # Regular expression rules for simple tokens
+    t_LBRACKET = r'\['
+    t_RBRACKET = r'\]'
+    t_LBRACE = r'{'
+    t_RBRACE = r'}'
+    t_COMMAND = r'\\([@a-zA-Z]+|[^\\])'
+    t_NEWLINE = r'\\\\'
+    SPECIAL_CHARACTERS = (
+            t_LBRACKET +
+            t_RBRACKET +
+            t_RBRACE +
+            t_LBRACE +
+            r"\\" +
+            r" " +
+            r"\n" +
+            r"\r" +
+            r"%" +
+            r"=" +
+            r","
+            )
+    t_CHARACTER = r'[^{}]'.format(SPECIAL_CHARACTERS)
+    t_EQUAL = r'='
+    t_COMMA = r','
+
+    t_SPACE = r'[ \t\n\r]+'
+
+    def __init__(self):
+        self.__class__.lexer = lex.lex(module = self)
+
+    # Define a rule so we can track line numbers
+    def t_newline(self, t):
+        r'\n+'
+        t.lexer.lineno += len(t.value)
+
+    def t_comment(self, t):
+        r'%.*'
+        pass
+
+    # Error handling rule
+    def t_error(self, t):
+        print("Illegal character '%s'" % t.value[0]) # TODO log
+        t.lexer.skip(1)
+
+class SongLexer(SimpleLexer):
+
+    states = (
+        ('beginsong', 'inclusive'),
+        )
+
+    # State beginsong
+    def t_INITIAL_BEGINSONG(self, t):
+        r'\\beginsong'
+        t.lexer.push_state('beginsong')
+        t.lexer.open_brackets = 0
+        t.lexer.open_braces = 0
+        return t
+
+    def t_beginsong_LBRACKET(self, t):
+        r'\['
+        if t.lexer.open_brackets == 0:
+            t.type = 'SONG_LOPTIONS'
+            t.lexer.open_braces += 1 # TODO Explain
+        t.lexer.open_brackets += 1
+        return t
+
+    def t_beginsong_RBRACKET(self, t):
+        r'\]'
+        t.lexer.open_brackets -= 1
+        if t.lexer.open_brackets == 0:
+            t.type = 'SONG_ROPTIONS'
+            t.lexer.open_braces -= 1 # TODO Explain
+            t.lexer.pop_state()
+            for __ignored in t.lexer: # TODO Explain
+                pass
+        return t
+
+    def t_beginsong_LBRACE(self, t):
+        r'{'
+        if t.lexer.open_braces == 0:
+            t.type = 'SONG_LTITLE'
+        t.lexer.open_braces += 1
+        return t
+
+    def t_beginsong_RBRACE1(self, t):
+        r'}(?![ \t\r\n]*\[)'
+        t.lexer.open_braces -= 1
+        t.type = 'RBRACE'
+        if t.lexer.open_braces == 0:
+            t.lexer.pop_state()
+            t.type = 'SONG_RTITLE'
+        return t
+
+    def t_beginsong_RBRACE2(self, t):
+        r'}(?=[ \t\r\n]*\[)'
+        t.lexer.open_braces -= 1
+        t.type = 'RBRACE'
+        if t.lexer.open_braces == 0:
+            t.type = 'SONG_RTITLE'
+        return t
+
diff --git a/patacrep/latex/parsetab.py b/patacrep/latex/parsetab.py
new file mode 100644
index 00000000..b98cd59e
--- /dev/null
+++ b/patacrep/latex/parsetab.py
@@ -0,0 +1,72 @@
+
+# parsetab.py
+# This file is automatically generated. Do not edit.
+_tabversion = '3.2'
+
+_lr_method = 'LALR'
+
+_lr_signature = b'\xa4\n\x7f%6\xc5\x1d\x1cV\xd9V\xf5\x07\xd5\x10\x10'
+    
+_lr_action_items = {'LBRACKET':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,55,60,62,70,],[9,9,9,9,9,9,-9,9,9,9,9,-9,9,-9,-9,-17,-21,-9,-9,-14,9,-19,-26,9,-9,-18,-20,-10,-16,-9,-12,-13,-11,9,9,9,9,9,-24,-22,-15,-25,9,-23,]),'SONG_ROPTIONS':([43,66,74,75,76,79,80,84,],[-11,70,-9,-9,-34,-28,-27,-33,]),'$end':([0,1,2,3,4,5,6,7,8,10,11,13,14,15,16,17,18,19,20,21,22,23,24,26,27,28,29,31,32,33,35,36,37,38,39,40,41,42,43,52,53,55,60,70,],[-9,-9,0,-8,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-6,-3,-5,-1,-4,-17,-21,-9,-7,-9,-14,-9,-19,-2,-26,-9,-18,-20,-10,-16,-9,-12,-13,-11,-24,-22,-15,-25,-23,]),'SPACE':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,55,60,62,70,74,75,81,],[10,10,10,10,10,10,-9,10,10,-9,10,-9,10,-9,-9,-17,-21,-9,-9,-14,-9,-19,-26,50,-9,-18,-20,-10,-16,-9,-12,-13,-11,50,50,50,50,50,-24,-22,-15,-25,50,-23,77,77,77,]),'COMMAND':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,55,60,62,70,],[11,11,11,11,11,11,-9,11,11,-9,11,-9,11,-9,-9,-17,-21,-9,-9,-14,-9,-19,-26,11,-9,-18,-20,-10,-16,-9,-12,-13,-11,11,11,11,11,11,-24,-22,-15,-25,11,-23,]),'RBRACKET':([1,3,4,5,6,7,8,9,10,11,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,31,32,33,35,36,37,38,39,40,41,42,43,52,53,55,60,70,],[-9,-8,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-6,-3,-5,-1,-4,-17,-21,-9,38,-7,-9,-14,-9,-19,-2,-26,-9,-18,-20,-10,-16,-9,-12,-13,-11,-24,-22,-15,-25,-23,]),'LBRACE':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,55,60,62,70,71,],[12,12,12,12,12,12,-9,12,12,-9,12,-9,12,-9,-9,-17,-21,-9,12,-14,-9,-19,-26,12,-9,-18,-20,-10,-16,12,-12,-13,-11,12,12,12,12,12,-24,-22,-15,-25,12,-23,12,]),'SONG_LOPTIONS':([15,33,35,60,],[-9,-26,54,-25,]),'CHARACTER':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,54,55,60,62,68,70,77,81,82,83,],[8,8,8,8,8,8,24,8,8,-9,8,24,8,-9,24,-17,-21,24,-9,-14,-9,-19,-26,8,-9,-18,-20,-10,-16,-9,-12,-13,-11,8,8,8,8,8,-24,-22,68,-15,-25,8,68,-23,-31,-9,68,-32,]),'NEWLINE':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,50,51,52,53,55,56,57,58,59,60,61,62,69,70,],[7,7,7,7,7,7,-9,7,7,-9,7,-9,7,-9,-9,-17,-21,-9,-9,-14,-9,-19,-26,-9,-9,-18,-20,-10,-16,-9,-12,-13,-11,-9,-43,-9,-9,-9,-9,62,-24,-22,-15,-41,-40,-38,-39,-25,-42,-9,62,-23,]),'error':([71,],[74,]),'EQUAL':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,54,55,60,62,65,67,68,70,72,77,81,82,83,],[13,13,13,13,13,13,-9,13,13,-9,13,-9,13,-9,-9,-17,-21,-9,-9,-14,-9,-19,-26,13,-9,-18,-20,-10,-16,-9,-12,-13,-11,13,13,13,13,13,-24,-22,-9,-15,-25,13,-30,71,-9,-23,-29,-31,-9,-9,-32,]),'COMMA':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,50,52,53,55,60,62,70,74,75,76,77,78,],[16,16,16,16,16,16,-9,16,16,-9,16,-9,16,-9,-9,-17,-21,-9,-9,-14,-9,-19,-26,16,-9,-18,-20,-10,-16,-9,-12,-13,-11,16,16,16,16,16,-24,-22,-15,-25,16,-23,-9,-9,-32,-31,81,]),'RBRACE':([1,3,4,5,6,7,8,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,26,27,28,29,30,31,32,33,35,36,37,38,39,40,41,42,43,52,53,55,60,70,],[-9,-8,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-9,-6,-3,-5,-1,-4,-17,-21,-9,-7,-9,-14,-9,43,-19,-2,-26,-9,-18,-20,-10,-16,-9,-12,-13,-11,-24,-22,-15,-25,-23,]),'SONG_LTITLE':([15,],[34,]),'BEGINSONG':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,22,23,24,27,28,29,31,33,35,36,37,38,39,40,41,42,43,52,53,55,60,70,],[15,15,15,15,15,15,-9,15,15,-9,15,-9,15,-9,-9,-17,-21,-9,-9,-14,-9,-19,-26,-9,-18,-20,-10,-16,-9,-12,-13,-11,-24,-22,-15,-25,-23,]),'SONG_RTITLE':([8,11,13,16,22,23,24,27,28,29,31,34,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,55,56,57,58,59,61,62,63,64,69,73,],[-9,-9,-9,-9,-17,-21,-9,-9,-14,-9,-19,-9,-18,-20,-10,-16,-9,-12,-13,-11,-9,-43,-9,-9,-9,60,-9,-9,-15,-41,-40,-38,-39,-42,-9,-37,-35,-9,-36,]),}
+
+_lr_action = { }
+for _k, _v in _lr_action_items.items():
+   for _x,_y in zip(_v[0],_v[1]):
+      if not _x in _lr_action:  _lr_action[_x] = { }
+      _lr_action[_x][_k] = _y
+del _lr_action_items
+
+_lr_goto_items = {'word':([0,1,4,5,6,7,9,10,12,14,34,44,46,47,48,50,62,],[1,1,1,1,1,1,1,1,1,1,44,44,44,44,44,44,44,]),'expression':([0,1,4,5,6,7,9,10,12,14,],[2,17,18,19,20,21,25,26,30,32,]),'dictionary_next':([74,75,],[79,80,]),'empty':([0,1,4,5,6,7,8,9,10,11,12,13,14,15,16,24,27,29,34,35,40,44,46,47,48,50,51,54,62,68,69,74,75,81,82,],[3,3,3,3,3,3,23,3,3,28,3,23,3,33,23,23,39,28,45,52,39,45,45,45,45,45,63,65,45,65,63,76,76,83,65,]),'dictionary':([54,82,],[66,84,]),'songbrackets':([35,],[53,]),'command':([0,1,4,5,6,7,9,10,12,14,34,44,46,47,48,50,62,],[4,4,4,4,4,4,4,4,4,4,46,46,46,46,46,46,46,]),'identifier':([54,68,82,],[67,72,67,]),'songbraces':([15,],[35,]),'brackets_list':([11,29,],[27,42,]),'brackets':([0,1,4,5,6,7,9,10,11,12,14,29,34,44,46,47,48,50,62,],[6,6,6,6,6,6,6,6,29,6,6,29,47,47,47,47,47,47,47,]),'word_next':([8,13,16,24,],[22,31,36,37,]),'beginsong':([0,1,4,5,6,7,9,10,12,14,],[5,5,5,5,5,5,5,5,5,5,]),'title':([34,44,46,47,48,50,62,],[51,56,57,58,59,61,69,]),'titles_next':([51,69,],[64,73,]),'braces':([0,1,4,5,6,7,9,10,12,14,27,34,40,44,46,47,48,50,62,71,],[14,14,14,14,14,14,14,14,14,14,40,48,40,48,48,48,48,48,48,75,]),'separator':([74,75,81,],[78,78,82,]),'titles':([34,],[49,]),'braces_list':([27,40,],[41,55,]),}
+
+_lr_goto = { }
+for _k, _v in _lr_goto_items.items():
+   for _x,_y in zip(_v[0],_v[1]):
+       if not _x in _lr_goto: _lr_goto[_x] = { }
+       _lr_goto[_x][_k] = _y
+del _lr_goto_items
+_lr_productions = [
+  ("S' -> expression","S'",1,None,None,None),
+  ('expression -> brackets expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',8),
+  ('expression -> braces expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',9),
+  ('expression -> command expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',10),
+  ('expression -> NEWLINE expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',11),
+  ('expression -> beginsong expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',12),
+  ('expression -> word expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',13),
+  ('expression -> SPACE expression','expression',2,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',14),
+  ('expression -> empty','expression',1,'p_expression','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',15),
+  ('empty -> <empty>','empty',0,'p_empty','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',26),
+  ('brackets -> LBRACKET expression RBRACKET','brackets',3,'p_brackets','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',30),
+  ('braces -> LBRACE expression RBRACE','braces',3,'p_braces','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',34),
+  ('command -> COMMAND brackets_list braces_list','command',3,'p_command','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',38),
+  ('brackets_list -> brackets brackets_list','brackets_list',2,'p_brackets_list','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',42),
+  ('brackets_list -> empty','brackets_list',1,'p_brackets_list','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',43),
+  ('braces_list -> braces braces_list','braces_list',2,'p_braces_list','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',52),
+  ('braces_list -> empty','braces_list',1,'p_braces_list','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',53),
+  ('word -> CHARACTER word_next','word',2,'p_word','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',62),
+  ('word -> COMMA word_next','word',2,'p_word','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',63),
+  ('word -> EQUAL word_next','word',2,'p_word','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',64),
+  ('word_next -> CHARACTER word_next','word_next',2,'p_word_next','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',69),
+  ('word_next -> empty','word_next',1,'p_word_next','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',70),
+  ('beginsong -> BEGINSONG songbraces songbrackets','beginsong',3,'p_beginsong','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',78),
+  ('songbrackets -> SONG_LOPTIONS dictionary SONG_ROPTIONS','songbrackets',3,'p_songbrackets','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',82),
+  ('songbrackets -> empty','songbrackets',1,'p_songbrackets','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',83),
+  ('songbraces -> SONG_LTITLE titles SONG_RTITLE','songbraces',3,'p_songbraces','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',91),
+  ('songbraces -> empty','songbraces',1,'p_songbraces','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',92),
+  ('dictionary -> identifier EQUAL braces dictionary_next','dictionary',4,'p_dictionary','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',100),
+  ('dictionary -> identifier EQUAL error dictionary_next','dictionary',4,'p_dictionary','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',101),
+  ('identifier -> CHARACTER identifier','identifier',2,'p_identifier','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',111),
+  ('identifier -> empty','identifier',1,'p_identifier','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',112),
+  ('separator -> SPACE','separator',1,'p_separator','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',120),
+  ('separator -> empty','separator',1,'p_separator','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',121),
+  ('dictionary_next -> separator COMMA separator dictionary','dictionary_next',4,'p_dictonary_next','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',126),
+  ('dictionary_next -> empty','dictionary_next',1,'p_dictonary_next','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',127),
+  ('titles -> title titles_next','titles',2,'p_titles','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',135),
+  ('titles_next -> NEWLINE title titles_next','titles_next',3,'p_titles_next','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',139),
+  ('titles_next -> empty','titles_next',1,'p_titles_next','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',140),
+  ('title -> brackets title','title',2,'p_title','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',148),
+  ('title -> braces title','title',2,'p_title','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',149),
+  ('title -> command title','title',2,'p_title','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',150),
+  ('title -> word title','title',2,'p_title','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',151),
+  ('title -> SPACE title','title',2,'p_title','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',152),
+  ('title -> empty','title',1,'p_title','/home/louis/projets/patacrep/patacrep/patacrep/latex/syntax.py',153),
+]
diff --git a/patacrep/latex/syntax.py b/patacrep/latex/syntax.py
new file mode 100644
index 00000000..f161b19c
--- /dev/null
+++ b/patacrep/latex/syntax.py
@@ -0,0 +1,194 @@
+import ply.yacc as yacc
+import inspect # TODO supprimer
+
+from patacrep.latex.lexer import tokens, SimpleLexer, SongLexer
+from patacrep.latex import ast
+from patacrep.latex.detex import detex
+
+class Parser:
+
+    def __init__(self, filename=None):
+        self.tokens = tokens
+        self.ast = ast.AST
+        self.ast.init_metadata()
+        self.filename = filename
+
+    def __find_column(self, token):
+        last_cr = token.lexer.lexdata.rfind('\n',0,token.lexpos)
+        if last_cr < 0:
+            last_cr = 0
+        column = (token.lexpos - last_cr) + 1
+        return column
+
+    def p_error(self, p):
+        print("Erreur fichier {}, ligne {}, position {}.".format( # TODO
+            str(self.filename),
+            p.lineno,
+            self.__find_column(p),
+            )
+            )
+
+    def p_expression(self, p):
+        """expression : brackets expression
+                      | braces expression
+                      | command expression
+                      | NEWLINE expression
+                      | beginsong expression
+                      | word expression
+                      | SPACE expression
+                      | empty
+        """
+        if len(p) == 3:
+            if p[2] is None:
+                p[0] = ast.Expression(p[1])
+            else:
+                p[0] = p[2].prepend(p[1])
+        else:
+            p[0] = None
+
+    def p_empty(self, p):
+        """empty :"""
+        return None
+
+    def p_brackets(self, p):
+        """brackets : LBRACKET expression RBRACKET"""
+        p[0] = p[2]
+
+    def p_braces(self, p):
+        """braces : LBRACE expression RBRACE"""
+        p[0] = p[2]
+
+    def p_command(self, p):
+        """command : COMMAND brackets_list braces_list"""
+        p[0] = ast.Command(p[1], p[2], p[3])
+
+    def p_brackets_list(self, p):
+        """brackets_list : brackets brackets_list
+                         | empty
+        """
+        if len(p) == 3:
+            p[0] = p[2]
+            p[0].insert(0, p[1])
+        else:
+            p[0] = []
+
+    def p_braces_list(self, p):
+        """braces_list : braces braces_list
+                       | empty
+        """
+        if len(p) == 3:
+            p[0] = p[2]
+            p[0].insert(0, p[1])
+        else:
+            p[0] = []
+
+    def p_word(self, p):
+        """word : CHARACTER word_next
+                | COMMA word_next
+                | EQUAL word_next
+        """
+        p[0] = p[1] + p[2]
+
+    def p_word_next(self, p):
+        """word_next : CHARACTER word_next
+                     | empty
+        """
+        if len(p) == 2:
+            p[0] = ""
+        else:
+            p[0] = p[1] + p[2]
+
+    def p_beginsong(self, p):
+        """beginsong : BEGINSONG separator songbraces separator songbrackets"""
+        self.ast.metadata["@titles"] = p[3]
+        self.ast.metadata.update(p[5])
+
+    def p_songbrackets(self, p):
+        """songbrackets : SONG_LOPTIONS separator dictionary separator SONG_ROPTIONS
+                        | empty
+        """
+        if len(p) == 6:
+            p[0] = p[3]
+        else:
+            p[0] = {}
+
+    def p_songbraces(self, p):
+        """songbraces : SONG_LTITLE separator titles separator SONG_RTITLE
+                      | empty
+        """
+        if len(p) == 6:
+            p[0] = p[3]
+        else:
+            p[0] = []
+
+    def p_dictionary(self, p):
+        """dictionary : identifier EQUAL braces dictionary_next
+                      | identifier EQUAL error dictionary_next
+        """
+        if isinstance(p[3], ast.Expression):
+            p[0] = {}
+            p[0][p[1]] = p[3]
+            p[0].update(p[4])
+        else:
+            raise Exception("Do enclose arguments between braces.") # TODO
+
+    def p_identifier(self, p):
+        """identifier : CHARACTER identifier
+                      | empty
+        """
+        if len(p) == 2:
+            p[0] = ""
+        else:
+            p[0] = p[1] + p[2]
+
+    def p_separator(self, p):
+        """separator : SPACE
+                     | empty
+        """
+        p[0] = None
+
+    def p_dictonary_next(self, p):
+        """dictionary_next : separator COMMA separator dictionary
+                           | empty
+        """
+        if len(p) == 5:
+            p[0] = p[4]
+        else:
+            p[0] = {}
+
+    def p_titles(self, p):
+        """titles : title titles_next"""
+        p[0] = [p[1]] + p[2]
+
+    def p_titles_next(self, p):
+        """titles_next : NEWLINE title titles_next
+                       | empty
+        """
+        if len(p) == 2:
+            p[0] = []
+        else:
+            p[0] = [p[2]] + p[3]
+
+    def p_title(self, p):
+        """title : brackets title
+                 | braces title
+                 | command title
+                 | word title
+                 | SPACE title
+                 | empty
+        """
+        if len(p) == 2:
+            p[0] = None
+        else:
+            if p[2] is None:
+                p[0] = ast.Expression(p[1])
+            else:
+                p[0] = p[2].prepend(p[1])
+
+
+def tex2plain(string):
+    return detex(yacc.yacc(module = Parser()).parse(string, lexer = SimpleLexer().lexer))
+
+def parsesong(string, filename=None):
+    return detex(yacc.yacc(module = Parser(filename)).parse(string, lexer = SongLexer().lexer).metadata)
+
diff --git a/patacrep/latex/testing.py b/patacrep/latex/testing.py
new file mode 100644
index 00000000..f2d66510
--- /dev/null
+++ b/patacrep/latex/testing.py
@@ -0,0 +1,50 @@
+
+# Test it out
+song = r"""
+\selectlanguage{french}
+plop = tag
+% Un commentaire
+\columns{3}
+\beginsong{Titre un \\Titre deux \\ Tître t{ro}ïs \\ T\^itre quatre}[album={Tagada tsoin \"itsoin}, cov={pouf.png}] % un autre
+%\beginsong{Titre un \\Titre deux \\ Tître t{ro}ïs \\ T\^itre quatre}[album={Tagada tsoin \"itsoin}] % un autre
+%\beginsong{Titre un \\Titre deux \\ Tître t{ro}ïs \\ T\^itre quatre}
+
+  Dans [Dm6]cette ruedots [E7]
+"""
+
+isong = r"""
+\selectlanguage{french}
+\songcolumns{2}
+\beginsong{Tous les bateaux, tous les oiseaux}
+  [by={Michel Polnareff},cov={passe-present},album={Passé Présent}]
+
+  Dans \[Dm6]cette ruedots [E7]
+"""
+
+tex = "D\\^iacritiqu\\'Es"
+
+# Give the lexer some input
+#if 0:
+#    from syntax import parser
+#    print(parser.parse(data, debug=0))
+#    print(parser.parse(data).song_data())
+#else:
+#    from lexer import SimpleLexer
+#    lexer.input(data)
+#    for tok in lexer:
+#        print(tok)
+
+from patacrep.latex import tex2plain
+from patacrep.latex.syntax import parsesong
+from patacrep.latex.ast import AST
+
+print(tex2plain(tex) == "DîacritiquÉs")
+print(parsesong(song, AST))
+print({
+        "@titles": ["Titre un", "Titre deux", "Tître trois", "Tpitre quatre"],
+        "@languages": set(["french"]),
+        "@path": "TODO",
+        "album": "Tagada tsoin ïtsoin",
+        "cov": "pouf.png",
+        }
+        )
diff --git a/patacrep/songs.py b/patacrep/songs.py
index bf3ff3a6..43e70fe7 100644
--- a/patacrep/songs.py
+++ b/patacrep/songs.py
@@ -10,7 +10,7 @@ import pickle
 import re
 
 from patacrep.authors import processauthors
-from patacrep.latex import parsetex
+from patacrep.latex import parsesong
 
 LOGGER = logging.getLogger(__name__)
 
@@ -74,7 +74,7 @@ class Song(object):
     cached_attributes = [
             "titles",
             "unprefixed_titles",
-            "args",
+            "data",
             "datadir",
             "fullpath",
             "subpath",
@@ -110,8 +110,9 @@ class Song(object):
                         ))
 
         # Data extraction from the latex song
-        data = parsetex(self.fullpath)
-        self.titles = data['titles']
+        self.data = parsesong(self.fullpath)
+        self.titles = self.data['@titles']
+        self.languages = self.data['@languages']
         self.datadir = datadir
         self.unprefixed_titles = [
                 unprefixed_title(
@@ -121,12 +122,10 @@ class Song(object):
                 for title
                 in self.titles
                 ]
-        self.args = data['args']
         self.subpath = subpath
-        self.languages = data['languages']
-        if "by" in self.args:
+        if "by" in self.data:
             self.authors = processauthors(
-                    self.args["by"],
+                    self.data["by"],
                     **config["_compiled_authwords"]
                     )
         else:
@@ -148,7 +147,7 @@ class Song(object):
                     )
 
     def __repr__(self):
-        return repr((self.titles, self.args, self.fullpath))
+        return repr((self.titles, self.data, self.fullpath))
 
 def unprefixed_title(title, prefixes):
     """Remove the first prefix of the list in the beginning of title (if any).