1 files changed, 101 insertions, 1 deletions
diff --git a/pygments/lexers/text.py b/pygments/lexers/text.py
index 1bab62f3..c0679aa6 100644
--- a/pygments/lexers/text.py
+++ b/pygments/lexers/text.py
@@ -25,7 +25,8 @@ __all__ = ['IniLexer', 'PropertiesLexer', 'SourcesListLexer', 'BaseMakefileLexer
            'RstLexer', 'VimLexer', 'GettextLexer', 'SquidConfLexer',
            'DebianControlLexer', 'DarcsPatchLexer', 'YamlLexer',
            'LighttpdConfLexer', 'NginxConfLexer', 'CMakeLexer', 'HttpLexer',
-           'PyPyLogLexer', 'RegeditLexer', 'HxmlLexer', 'EbnfLexer']
+           'PyPyLogLexer', 'RegeditLexer', 'HxmlLexer', 'EbnfLexer',
+           'TodotxtLexer']
 
 
 class IniLexer(RegexLexer):
@@ -1911,3 +1912,102 @@ class EbnfLexer(RegexLexer):
             (r'([a-zA-Z][a-zA-Z0-9 \-]*)', Keyword),
           ],
     }
+
+class TodotxtLexer(RegexLexer):
+    """
+    Lexer for `Todo.txt <http://todotxt.com/>`_ todo list format.
+
+    .. versionadded:: 2.0
+    """
+    
+    name = 'Todotxt'
+    aliases = ['todotxt']
+    # *.todotxt is not a standard extension for Todo.txt files; including it
+    # makes testing easier, and also makes autodetecting file type easier.
+    filenames = ['todo.txt', '*.todotxt']
+    mimetypes = ['text/x-todo']
+
+    ## Aliases mapping standard token types of Todo.txt format concepts
+    CompleteTaskText = Operator # Chosen to de-emphasize complete tasks
+    IncompleteTaskText = Text # Incomplete tasks should look like plain text 
+    
+    # Priority should have most emphasis to indicate importance of tasks
+    Priority = Generic.Heading
+    # Dates should have next most emphasis because time is important
+    Date = Generic.Subheading
+    
+    # Project and context should have equal weight, and be in different colors
+    Project = Generic.Error 
+    Context = String
+    
+    # If tag functionality is added, it should have the same weight as Project
+    # and Context, and a different color. Generic.Traceback would work well.
+
+    # Regex patterns for building up rules; dates, priorities, projects, and
+    # contexts are all atomic
+    # TODO: Make date regex more ISO 8601 compliant
+    date_regex = r'\d{4,}-\d{2}-\d{2}' 
+    priority_regex = r'\([A-Z]\)'
+    project_regex = r'\+\S+'
+    context_regex = r'@\S+'
+
+    # Compound regex expressions
+    complete_one_date_regex = r'(x )(' + date_regex + r')'
+    complete_two_date_regex = (complete_one_date_regex + r'( )(' + 
+                                date_regex + r')')
+    priority_date_regex = r'(' + priority_regex + r')( )(' + date_regex + r')'
+
+    tokens = {
+        # Should parse starting at beginning of line; each line is a task
+        'root': [
+            ## Complete task entry points: two total:
+            # 1. Complete task with two dates
+            (complete_two_date_regex, bygroups(CompleteTaskText, Date,
+                                               CompleteTaskText, Date),
+             'complete'),
+            # 2. Complete task with one date
+            (complete_one_date_regex, bygroups(CompleteTaskText, Date),
+             'complete'),
+            
+            ## Incomplete task entry points: six total:
+            # 1. Priority plus date
+            (priority_date_regex, bygroups(Priority, IncompleteTaskText, Date),
+             'incomplete'),
+            # 2. Priority only
+            (priority_regex, Priority, 'incomplete'),
+            # 3. Leading date
+            (date_regex, Date, 'incomplete'),
+            # 4. Leading context
+            (context_regex, Context, 'incomplete'),
+            # 5. Leading project
+            (project_regex, Project, 'incomplete'),
+            # 6. Non-whitespace catch-all
+            ('\S+', IncompleteTaskText, 'incomplete'),
+        ],
+            
+        # Parse a complete task
+        'complete': [
+            # Newline indicates end of task, should return to root
+            (r'\s*\n', CompleteTaskText, '#pop'),
+            # Tokenize contexts and projects
+            (context_regex, Context),
+            (project_regex, Project),
+            # Tokenize non-whitespace text
+            ('\S+', CompleteTaskText),
+            # Tokenize whitespace not containing a newline
+            ('\s+', CompleteTaskText),
+        ],
+
+        # Parse an incomplete task
+        'incomplete': [
+            # Newline indicates end of task, should return to root
+            (r'\s*\n', IncompleteTaskText, '#pop'),
+            # Tokenize contexts and projects
+            (context_regex, Context),
+            (project_regex, Project),
+            # Tokenize non-whitespace text
+            ('\S+', IncompleteTaskText),
+            # Tokenize whitespace not containing a newline
+            ('\s+', IncompleteTaskText),
+        ],
+    }