Bison News
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-* Changes in version 2.5 (????-??-??):
+* Changes in version 2.5.1 (????-??-??):
+
+** Minor improvements have been made to the manual.
+
+* Changes in version 2.5 (2011-05-14):
** Grammar symbol names can now contain non-initial dashes:
IELR(1) is a minimal LR(1) parser table generation algorithm. That
is, given any context-free grammar, IELR(1) generates parser tables
- with the full language recognition power of canonical LR(1) but with
+ with the full language-recognition power of canonical LR(1) but with
nearly the same number of parser states as LALR(1). This reduction
in parser states is often an order of magnitude. More importantly,
because canonical LR(1)'s extra parser states may contain duplicate
The old names are now deprecated but will be maintained indefinitely
for backward compatibility.
-*** Values no longer need to be quoted in grammar file:
+*** Values no longer need to be quoted in the grammar file:
If a %define value is an identifier, it no longer needs to be placed
within quotations marks. For example,
bison -Werror,none,yacc gram.y
-*** The `none' category now disables all Bison warnings.
+*** The `none' category now disables all Bison warnings:
Previously, the `none' category disabled only Bison warnings for
which there existed a specific -W/--warning category. However,
bison -Wnone gram.y
+** Precedence directives can now assign token number 0:
+
+ Since Bison 2.3b, which restored the ability of precedence
+ directives to assign token numbers, doing so for token number 0 has
+ produced an assertion failure. For example:
+
+ %left END 0
+
+ This bug has been fixed.
+
* Changes in version 2.4.3 (2010-08-05):
** Bison now obeys -Werror and --warnings=error for warnings about