From 7f7fa2f91467fdb2b11312be8562e7b51fdeb199 Mon Sep 17 00:00:00 2001
From: Sebastian Koslowski <sebastian.koslowski@gmail.com>
Date: Tue, 3 May 2016 17:13:08 +0200
Subject: grc: added yaml/mako support
Includes basic converter from XML/Cheetah to YAML/Mako based block format.
---
grc/core/utils/expr_utils.py | 158 ++++++++++++++++++++++++++-----------------
1 file changed, 96 insertions(+), 62 deletions(-)
(limited to 'grc/core/utils/expr_utils.py')
diff --git a/grc/core/utils/expr_utils.py b/grc/core/utils/expr_utils.py
index cc03e9cb1c..427585e93c 100644
--- a/grc/core/utils/expr_utils.py
+++ b/grc/core/utils/expr_utils.py
@@ -23,17 +23,105 @@ import string
import six
+
+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, var_chars=VAR_CHARS + '.')
+ for i, es in enumerate(expr_splits):
+ if es in list(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(v for v in vars if v in expr_toks)
+
+
+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 = {get_id(obj): obj for obj in objects}
+ # Map obj id to expression code
+ id2expr = {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]
+
+
+import ast
+
+
+def dependencies(expr, names=None):
+ node = ast.parse(expr, mode='eval')
+ used_ids = frozenset([n.id for n in ast.walk(node) if isinstance(n, ast.Name)])
+ return used_ids & names if names else used_ids
+
+
+def sort_objects2(objects, id_getter, expr_getter, check_circular=True):
+ known_ids = {id_getter(obj) for obj in objects}
+
+ def dependent_ids(obj):
+ deps = dependencies(expr_getter(obj))
+ return [id_ if id_ in deps else None for id_ in known_ids]
+
+ objects = sorted(objects, key=dependent_ids)
+
+ if check_circular: # walk var defines step by step
+ defined_ids = set() # variables defined so far
+ for obj in objects:
+ deps = dependencies(expr_getter(obj), known_ids)
+ if not defined_ids.issuperset(deps): # can't have an undefined dep
+ raise RuntimeError(obj, deps, defined_ids)
+ defined_ids.add(id_getter(obj)) # define this one
+
+ return objects
+
+
+
+
VAR_CHARS = string.ascii_letters + string.digits + '_'
-class graph(object):
+class _graph(object):
"""
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 node_key in self._graph:
@@ -61,7 +149,7 @@ class graph(object):
return self._graph[node_key]
-def expr_split(expr, var_chars=VAR_CHARS):
+def _expr_split(expr, var_chars=VAR_CHARS):
"""
Split up an expression by non alphanumeric characters, including underscore.
Leave strings in-tact.
@@ -93,40 +181,7 @@ def expr_split(expr, var_chars=VAR_CHARS):
return [t for t in toks if t]
-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, var_chars=VAR_CHARS + '.')
- for i, es in enumerate(expr_splits):
- if es in list(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(v for v in vars if v in expr_toks)
-
-
-def get_graph(exprs):
+def _get_graph(exprs):
"""
Get a graph representing the variable dependencies
@@ -138,7 +193,7 @@ def get_graph(exprs):
"""
vars = list(exprs.keys())
# Get dependencies for each expression, load into graph
- var_graph = graph()
+ var_graph = _graph()
for var in vars:
var_graph.add_node(var)
for var, expr in six.iteritems(exprs):
@@ -148,7 +203,7 @@ def get_graph(exprs):
return var_graph
-def sort_variables(exprs):
+def _sort_variables(exprs):
"""
Get a list of variables in order of dependencies.
@@ -159,7 +214,7 @@ def sort_variables(exprs):
a list of variable names
@throws Exception circular dependencies
"""
- var_graph = get_graph(exprs)
+ var_graph = _get_graph(exprs)
sorted_vars = list()
# Determine dependency order
while var_graph.get_nodes():
@@ -173,24 +228,3 @@ def sort_variables(exprs):
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]
--
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