class CyclicConfigError(ConfigError):
pass
+class ParseProxy(list):
+ """Proxy helper class around values returned by `parse` and `parse_file`,
+ useful in "with" constructs."""
+ def __init__(self, config, parsed_ops):
+ super(ParseProxy, self).__init__(parsed_ops)
+ self.config = config
+ def __enter__(self):
+ pass
+ def __exit__(self, etype, value, traceback):
+ self.config.remove(list(self))
+
class ConfigTree(object):
"""
if isinstance(keys, types.StringTypes):
keys = [keys]
for key in keys:
- self.lookup(key, create=True).fix()
-
- def parse(self, s, source=None, level=0):
- """Parse `s` (stream/string) into the tree, see `moe.confparser.ConfigParser` for details."""
- import moe.confparser
- p = moe.confparser.ConfigParser(text, self, source=source, level=level)
- p.parse()
+ self.lookup(key, create=False).fix()
+
+ def unfix(self, keys):
+ "Unfix value of variable or list of variables. Unfixing undefined variable raises `UndefinedError`."
+ if isinstance(keys, types.StringTypes):
+ keys = [keys]
+ for key in keys:
+ self.lookup(key, create=False).unfix()
- def parse_file(self, filename, desc=None, level=0):
- """Parse an utf-8 file into the tree, see `moe.confparser.ConfigParser` for details.
+ def remove(self, parsed):
+ """Given a list [(varname, `Operation`)] as returned by `parse` or `parse_file`,
+ removes the operations from the respective variables config tree.
+ Variables/operations not present int the tree raise ValueError.
+ """
+ for vname, o in parsed:
+ v = self.lookup(vname, create = True)
+ v.remove_operation(o)
+
+ def parse(self, s, source=None, level=0, proxy=True):
+ """Parse `s` (stream/string) into the tree, see `moe.config_parser.ConfigParser` for details.
+ Returns list of parset operations: [(varname, `Operation`)].
+ By default returns a proxy list-like object that can be used in "with" constructs:
+
+ with config.parse("TEST='1'"):
+ print config['TEST']
+ raise StupidError
+ """
+ import moe.config_parser
+ p = moe.config_parser.ConfigParser(s, self, source=source, level=level)
+ l = p.parse()
+ if not proxy:
+ return l
+ return ParseProxy(self, l)
+
+ def parse_file(self, filename, desc=None, level=0, proxy=True):
+ """Parse an utf-8 file into the tree using func:`parse`.
Names the source "`filename` <`desc`>". """
with open(filename, 'rt') as f:
if desc:
filename += " <" + desc + ">"
- self.parse(f, source=filename, level=level)
+ return self.parse(f, source=filename, level=level, proxy=proxy)
class ConfigElem(object):
def variables(self):
"Return a set of variables used in the expressions"
- return set(sum([ list(op.expression.variables()) for op in self.operations ], []))
+ if not self.operations:
+ return set([])
+ return set.union(*[ op.expression.variables() for op in self.operations ])
def fix(self):
"""
"Handle the case when fixed, raise exc. on different evaluation"
val = super(ConfigVar,self).value(depth)
if self.fixed and self.fixed_val != val:
- raise VariableFixedError("value of var %s was fixed to %r but evaluated to %r", self.name, self.fixed_val, val)
+ raise VariableFixedError("value of var %r was fixed to %r but evaluated to %r", self.name, self.fixed_val, val)
return val
def add_operation(self, operation):
self.invalidate()
# Remove the operation
self.operations.remove(operation)
- # Remove dependencies on variables unused in other operations
+ # Remove dependencies on variables unused in other defining operations
vs = self.variables()
for v in operation.expression.variables():
if v not in vs:
self.exprlist[i] = unicode(e, 'ascii')
def variables(self):
- "Return an iterator of variables user in the expression"
- return itertools.ifilter(lambda e: isinstance(e, ConfigVar), self.exprlist)
+ "Return a set of variables used in the expression"
+ return set([e for e in self.exprlist if isinstance(e, ConfigVar)])
def __str__(self):
return self.original