Support for negative indices; more tests

app.py

@@ -31,18 +31,7 @@
 jinja2 = jinja2_.Environment( loader=jinja2_.FileSystemLoader( 'jinja2-assets' ) )
 
 import gist_it
-
-'''
-Take a (line) slice of content, based on a start/end index
-'''
-def take_slice(content, start_line = 0, end_line = 0):
-    if (start_line == 0 and end_line == 0):
-        return content
-
-    if (end_line == 0):
-        return '\n'.join(content.splitlines()[start_line:])
-
-    return '\n'.join(content.splitlines()[start_line:end_line])
+from gist_it import take_slice
 
 def render_gist_html( base, gist, document ):
     result = jinja2.get_template( 'gist.jinja.html' ).render( cgi = cgi, base = base, gist = gist, document = document )
@@ -84,7 +73,7 @@ def get( self, location ):
             return
 
         else:
-            gist = gist_it.Gist.parse( location, slice = self.request.get( 'slice' ) )
+            gist = gist_it.Gist.parse( location, slice_ = self.request.get( 'slice' ) )
             if not gist:
                 self.response.set_status( 500 )
                 self.response.out.write( "Unable to parse \"%s\": Not a valid repository path?" % ( location ) )

gist_it.py

@@ -9,10 +9,22 @@ def parse( location, **arguments ):
     return Gist.parse( location, **arguments )
 
 def parse_slice( slice_ ):
-    match = re.match( r'^(\d*):?(\d*)$', slice_ )
+    match = re.match( r'^(-?\d+)?:?(-?\d+)?$', slice_ )
     if match is None:
         return ( 0, 0 )
-    return map( lambda _: int(_) if len(_) else 0, match.groups(0) )
+    return map( lambda _: int(_) if _ is not None else 0, match.groups(0) )
+
+'''
+Take a (line) slice of content, based on a start/end index
+'''
+def take_slice( content, start_line = 0, end_line = 0 ):
+    if (start_line == 0 and end_line == 0):
+        return content
+
+    if (end_line == 0):
+        return '\n'.join(content.splitlines()[start_line:])
+
+    return '\n'.join(content.splitlines()[start_line:end_line])
 
 class Gist:
 
@@ -56,12 +68,18 @@ def parse( self, location, slice_ = '' ):
         user_repository_branch_path = parse[ 'user_repository_branch_path' ]    = '/'.join([ user_repository, branch, path ]);
         user_repository_url         = parse[ 'user_repository_url' ]            = urlparse.urljoin( 'https://github.com', user_repository )
 
+        slice_ = parse_slice( slice_ )
+        parse[ 'start_line' ] = slice_[0]
+        parse[ 'end_line' ] = slice_[1]
+
         return Gist( **parse )
 
     def __init__( self, **arguments ):
         for key in [ 'user', 'repository', 'branch', 'path',
                 'blob_path', 'blob_url',
                 'raw_path', 'raw_url', 
-                'user_repository', 'user_repository_branch_path', 'user_repository_url' ]:
+                'user_repository', 'user_repository_branch_path', 'user_repository_url',
+                'start_line', 'end_line',
+                ]:
             setattr( self, key, arguments[ key ] )
 

test/test_gist_it.py

@@ -30,7 +30,13 @@ def runTest( self ):
         self.assertEqual( gist.user_repository_branch_path, 'robertkrimen/yzzy-projection/master/src/yzzy/projection/View.as' )
         self.assertEqual( gist.user_repository_url, 'https://github.com/robertkrimen/yzzy-projection' )
 
+        self.assertEqual( gist.start_line, 0 )
+        self.assertEqual( gist.end_line, 0 )
+
         gist = gist_it.parse( 'github/robertkrimen/yzzy-projection/raw/master/src/yzzy/projection/View.as', slice_ = '1:' )
 
+        self.assertEqual( gist.start_line, 1 )
+        self.assertEqual( gist.end_line, 0 )
+
 if __name__ == '__main__':
     unittest2.main()

test/test_slice.py

@@ -50,5 +50,38 @@ def runTest( self ):
         self.assertEqual( slice_[0], 0 )
         self.assertEqual( slice_[1], 0 )
 
+        slice_ = gist_it.parse_slice( '-0:-0' )
+        self.assertEqual( len( slice_ ), 2 )
+        self.assertEqual( slice_[0], 0 )
+        self.assertEqual( slice_[1], 0 )
+
+        slice_ = gist_it.parse_slice( '-1:' )
+        self.assertEqual( len( slice_ ), 2 )
+        self.assertEqual( slice_[0], -1 )
+        self.assertEqual( slice_[1], 0 )
+
+        content = """
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6
+
+Line 8
+"""
+        self.assertEqual( gist_it.take_slice( content, 0, 0 ), content )
+        self.assertEqual( gist_it.take_slice( content, 1, 2 ), "Line 2" )
+        self.assertEqual( gist_it.take_slice( content, 0, 2 ), "\nLine 2" )
+        self.assertEqual( gist_it.take_slice( content, 0, -1 ), """
+Line 2
+Line 3
+Line 4
+Line 5
+Line 6
+""" )
+        self.assertEqual( gist_it.take_slice( content, -1, 0 ), "Line 8" )
+
+
+
 if __name__ == '__main__':
     unittest2.main()