invoking rule with argument

Author: introom

ometa/interp.py

@@ -20,13 +20,13 @@ class TrampolinedGrammarInterpreter(object):
     An interpreter for OMeta grammars that processes input
     incrementally.
     """
-    def __init__(self, grammar, ruleName, callback=None, globals=None):
+    def __init__(self, grammar, rule, callback=None, globals=None):
         self.grammar = grammar
         self.position = 0
         self.callback = callback
         self.globals = globals or {}
         self.rules = decomposeGrammar(grammar)
-        self.next = self.apply(ruleName, None, ())
+        self.next = self.setNext(rule)
         self._localsStack = []
         self.currentResult = None
         self.input = InputStream([], 0)
@@ -68,6 +68,14 @@ def end(self):
             self.callback(*x)
 
 
+    def setNext(self, rule):
+        if isinstance(rule, basestring):
+            rule = (rule, )
+        if not isinstance(rule, (list, tuple)):
+            raise TypeError("rule should be a string, list or a tuple.")
+        return self.apply(rule[0], None, rule[1:])
+
+
     ## Implementation note: each method, instead of being a function
     ## returning a value, is a generator that will yield '_feed_me' an
     ## arbitrary number of times, then finally yield the value of the
@@ -148,10 +156,15 @@ def apply(self, ruleName, codeName, args):
         Invoke a rule, optionally with arguments.
         """
         argvals = []
-        for a in args:
-            for x in self._eval(a):
-                if x is _feed_me: yield x
-            argvals.append(x[0])
+        # we tell whether a rule is a manually set one by the codeName
+        # if it's None, then we think it's set by setNext
+        if codeName is None:
+            argvals = args
+        else:
+            for a in args:
+                for x in self._eval(a):
+                    if x is _feed_me: yield x
+                argvals.append(x[0])
         _locals = {}
         self._localsStack.append(_locals)
         try:

ometa/runtime.py

@@ -131,7 +131,6 @@ def joinErrors(errors):
     """
     if len(errors) == 1:
         return errors[0]
-
     highestPos = -1
     results = set()
     trail = None

ometa/tube.py

@@ -26,7 +26,7 @@ def _setupInterp(self):
         'initial'.
         """
         self._interp = TrampolinedGrammarInterpreter(
-            grammar=self.grammar, ruleName=self.receiver.currentRule,
+            grammar=self.grammar, rule=self.receiver.currentRule,
             callback=None, globals=self.bindings)