1 files changed, 132 insertions, 132 deletions
diff --git a/grc/python/expr_utils.py b/grc/python/expr_utils.py
index 67580f6ffc..85f420f04c 100644
--- a/grc/python/expr_utils.py
+++ b/grc/python/expr_utils.py
@@ -21,157 +21,157 @@ import string
 VAR_CHARS = string.letters + string.digits + '_'
 
 class graph(object):
-	"""
-	Simple graph structure held in a dictionary.
-	"""
+    """
+    Simple graph structure held in a dictionary.
+    """
 
-	def __init__(self): self._graph = dict()
+    def __init__(self): self._graph = dict()
 
-	def __str__(self): return str(self._graph)
+    def __str__(self): return str(self._graph)
 
-	def add_node(self, node_key):
-		if self._graph.has_key(node_key): return
-		self._graph[node_key] = set()
+    def add_node(self, node_key):
+        if self._graph.has_key(node_key): return
+        self._graph[node_key] = set()
 
-	def remove_node(self, node_key):
-		if not self._graph.has_key(node_key): return
-		for edges in self._graph.values():
-			if node_key in edges: edges.remove(node_key)
-		self._graph.pop(node_key)
+    def remove_node(self, node_key):
+        if not self._graph.has_key(node_key): return
+        for edges in self._graph.values():
+            if node_key in edges: edges.remove(node_key)
+        self._graph.pop(node_key)
 
-	def add_edge(self, src_node_key, dest_node_key):
-		self._graph[src_node_key].add(dest_node_key)
+    def add_edge(self, src_node_key, dest_node_key):
+        self._graph[src_node_key].add(dest_node_key)
 
-	def remove_edge(self, src_node_key, dest_node_key):
-		self._graph[src_node_key].remove(dest_node_key)
+    def remove_edge(self, src_node_key, dest_node_key):
+        self._graph[src_node_key].remove(dest_node_key)
 
-	def get_nodes(self): return self._graph.keys()
+    def get_nodes(self): return self._graph.keys()
 
-	def get_edges(self, node_key): return self._graph[node_key]
+    def get_edges(self, node_key): return self._graph[node_key]
 
 def expr_split(expr):
-	"""
-	Split up an expression by non alphanumeric characters, including underscore.
-	Leave strings in-tact.
-	#TODO ignore escaped quotes, use raw strings.
-	
-	Args:
-	    expr: an expression string
-	
-	Returns:
-	    a list of string tokens that form expr
-	"""
-	toks = list()
-	tok = ''
-	quote = ''
-	for char in expr:
-		if quote or char in VAR_CHARS:
-			if char == quote: quote = ''
-			tok += char
-		elif char in ("'", '"'):
-			toks.append(tok)
-			tok = char
-			quote = char
-		else:
-			toks.append(tok)
-			toks.append(char)
-			tok = ''
-	toks.append(tok)
-	return filter(lambda t: t, toks)
+    """
+    Split up an expression by non alphanumeric characters, including underscore.
+    Leave strings in-tact.
+    #TODO ignore escaped quotes, use raw strings.
+    
+    Args:
+        expr: an expression string
+    
+    Returns:
+        a list of string tokens that form expr
+    """
+    toks = list()
+    tok = ''
+    quote = ''
+    for char in expr:
+        if quote or char in VAR_CHARS:
+            if char == quote: quote = ''
+            tok += char
+        elif char in ("'", '"'):
+            toks.append(tok)
+            tok = char
+            quote = char
+        else:
+            toks.append(tok)
+            toks.append(char)
+            tok = ''
+    toks.append(tok)
+    return filter(lambda t: t, toks)
 
 def expr_replace(expr, replace_dict):
-	"""
-	Search for vars in the expression and add the prepend.
-	
-	Args:
-	    expr: an expression string
-	    replace_dict: a dict of find:replace
-	
-	Returns:
-	    a new expression with the prepend
-	"""
-	expr_splits = expr_split(expr)
-	for i, es in enumerate(expr_splits):
-		if es in replace_dict.keys():
-			expr_splits[i] = replace_dict[es]
-	return ''.join(expr_splits)
+    """
+    Search for vars in the expression and add the prepend.
+    
+    Args:
+        expr: an expression string
+        replace_dict: a dict of find:replace
+    
+    Returns:
+        a new expression with the prepend
+    """
+    expr_splits = expr_split(expr)
+    for i, es in enumerate(expr_splits):
+        if es in replace_dict.keys():
+            expr_splits[i] = replace_dict[es]
+    return ''.join(expr_splits)
 
 def get_variable_dependencies(expr, vars):
-	"""
-	Return a set of variables used in this expression.
-	
-	Args:
-	    expr: an expression string
-	    vars: a list of variable names
-	
-	Returns:
-	    a subset of vars used in the expression
-	"""
-	expr_toks = expr_split(expr)
-	return set(filter(lambda v: v in expr_toks, vars))
+    """
+    Return a set of variables used in this expression.
+    
+    Args:
+        expr: an expression string
+        vars: a list of variable names
+    
+    Returns:
+        a subset of vars used in the expression
+    """
+    expr_toks = expr_split(expr)
+    return set(filter(lambda v: v in expr_toks, vars))
 
 def get_graph(exprs):
-	"""
-	Get a graph representing the variable dependencies
-	
-	Args:
-	    exprs: a mapping of variable name to expression
-	
-	Returns:
-	    a graph of variable deps
-	"""
-	vars = exprs.keys()
-	#get dependencies for each expression, load into graph
-	var_graph = graph()
-	for var in vars: var_graph.add_node(var)
-	for var, expr in exprs.iteritems():
-		for dep in get_variable_dependencies(expr, vars):
-			if dep != var: var_graph.add_edge(dep, var)
-	return var_graph
+    """
+    Get a graph representing the variable dependencies
+    
+    Args:
+        exprs: a mapping of variable name to expression
+    
+    Returns:
+        a graph of variable deps
+    """
+    vars = exprs.keys()
+    #get dependencies for each expression, load into graph
+    var_graph = graph()
+    for var in vars: var_graph.add_node(var)
+    for var, expr in exprs.iteritems():
+        for dep in get_variable_dependencies(expr, vars):
+            if dep != var: var_graph.add_edge(dep, var)
+    return var_graph
 
 def sort_variables(exprs):
-	"""
-	Get a list of variables in order of dependencies.
-	
-	Args:
-	    exprs: a mapping of variable name to expression
-	
-	Returns:
-	    a list of variable names
-	@throws Exception circular dependencies
-	"""
-	var_graph = get_graph(exprs)
-	sorted_vars = list()
-	#determine dependency order
-	while var_graph.get_nodes():
-		#get a list of nodes with no edges
-		indep_vars = filter(lambda var: not var_graph.get_edges(var), var_graph.get_nodes())
-		if not indep_vars: raise Exception('circular dependency caught in sort_variables')
-		#add the indep vars to the end of the list
-		sorted_vars.extend(sorted(indep_vars))
-		#remove each edge-less node from the graph
-		for var in indep_vars: var_graph.remove_node(var)
-	return reversed(sorted_vars)
+    """
+    Get a list of variables in order of dependencies.
+    
+    Args:
+        exprs: a mapping of variable name to expression
+    
+    Returns:
+        a list of variable names
+    @throws Exception circular dependencies
+    """
+    var_graph = get_graph(exprs)
+    sorted_vars = list()
+    #determine dependency order
+    while var_graph.get_nodes():
+        #get a list of nodes with no edges
+        indep_vars = filter(lambda var: not var_graph.get_edges(var), var_graph.get_nodes())
+        if not indep_vars: raise Exception('circular dependency caught in sort_variables')
+        #add the indep vars to the end of the list
+        sorted_vars.extend(sorted(indep_vars))
+        #remove each edge-less node from the graph
+        for var in indep_vars: var_graph.remove_node(var)
+    return reversed(sorted_vars)
 
 def sort_objects(objects, get_id, get_expr):
-	"""
-	Sort a list of objects according to their expressions.
-	
-	Args:
-	    objects: the list of objects to sort
-	    get_id: the function to extract an id from the object
-	    get_expr: the function to extract an expression from the object
-	
-	Returns:
-	    a list of sorted objects
-	"""
-	id2obj = dict([(get_id(obj), obj) for obj in objects])
-	#map obj id to expression code
-	id2expr = dict([(get_id(obj), get_expr(obj)) for obj in objects])
-	#sort according to dependency
-	sorted_ids = sort_variables(id2expr)
-	#return list of sorted objects
-	return [id2obj[id] for id in sorted_ids]
+    """
+    Sort a list of objects according to their expressions.
+    
+    Args:
+        objects: the list of objects to sort
+        get_id: the function to extract an id from the object
+        get_expr: the function to extract an expression from the object
+    
+    Returns:
+        a list of sorted objects
+    """
+    id2obj = dict([(get_id(obj), obj) for obj in objects])
+    #map obj id to expression code
+    id2expr = dict([(get_id(obj), get_expr(obj)) for obj in objects])
+    #sort according to dependency
+    sorted_ids = sort_variables(id2expr)
+    #return list of sorted objects
+    return [id2obj[id] for id in sorted_ids]
 
 if __name__ == '__main__':
-	for i in sort_variables({'x':'1', 'y':'x+1', 'a':'x+y', 'b':'y+1', 'c':'a+b+x+y'}): print i
+    for i in sort_variables({'x':'1', 'y':'x+1', 'a':'x+y', 'b':'y+1', 'c':'a+b+x+y'}): print i