# HG changeset patch
# User Yuya Nishihara <yuya@tcha.org>
# Date 2015-07-05 02:54:14
# Node ID f0a77cb6316a0dcd9e0d9917bdfa16532e0866ef
# Parent  b3004d2738749aaaba4b6e2e8badf542cb1eea6d

parser: extract function that tests if next token may start new term

Future patches will separate primary expression and prefix operator actions.
This function will be used to resolve ambiguity of them.

This is a step to remove the old-style revexpr parser. We need both ":" and
":y" operators for backward compatibility.

diff --git a/mercurial/parser.py b/mercurial/parser.py
--- a/mercurial/parser.py
+++ b/mercurial/parser.py
@@ -29,6 +29,9 @@ class parser(object):
         t = self.current
         self.current = next(self._iter, None)
         return t
+    def _hasnewterm(self):
+        'True if next token may start new term'
+        return bool(self._elements[self.current[0]][1])
     def _match(self, m):
         'make sure the tokenizer matches an end condition'
         if self.current[0] != m:
@@ -59,7 +62,7 @@ class parser(object):
             token, value, pos = self._advance()
             infix, suffix = self._elements[token][2:]
             # check for suffix - next token isn't a valid prefix
-            if suffix and not self._elements[self.current[0]][1]:
+            if suffix and not self._hasnewterm():
                 expr = (suffix[0], expr)
             else:
                 # handle infix rules