X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/99c08fb6626f4aca4a7eb2e5d53dae43bc40771b..3cdc21cfd78fad8bfa885034f7a92c563deefbc5:/NEWS diff --git a/NEWS b/NEWS index cef62ee5..41ab73de 100644 --- a/NEWS +++ b/NEWS @@ -3,20 +3,35 @@ Bison News * Changes in version ?.? (????-??-??): -** Java skeleton improvements: +** Additional yylex/yyparse arguments + + The new directive %param declare additional argument to both yylex + and yyparse. The %lex-param, %parse-param, and %param directive + support one or more arguments. Instead of + + %lex-param {arg1_type *arg1} + %lex-param {arg2_type *arg2} + %parse-param {arg1_type *arg1} + %parse-param {arg2_type *arg2} + + one may now declare + + %param {arg1_type *arg1} {arg2_type *arg2} + +** Java skeleton improvements The constants for token names were moved to the Lexer interface. Also, it is possible to add code to the parser's constructors using "%code init" and "%define init_throws". -** Variable token.prefix +** Variable api.tokens.prefix - The variable token.prefix changes the way tokens are identified in + The variable api.tokens.prefix changes the way tokens are identified in the generated files. This is especially useful to avoid collisions with identifiers in the target language. For instance %token FILE for ERROR - %define token.prefix "TOK_" + %define api.tokens.prefix "TOK_" %% start: FILE for ERROR; @@ -25,6 +40,17 @@ Bison News use these prefixed token names, although the grammar itself still uses the short names (as in the sample rule given above). +** Variable api.namespace + + The "namespace" variable is renamed "api.namespace". Backward + compatibility is ensured, but upgrading is recommended. + +** Variable parse.error + + The variable error controls the verbosity of error messages. The + use of the %error-verbose directive is deprecated in favor of + %define parse.error "verbose". + * Changes in version 2.5 (????-??-??): ** IELR(1) and Canonical LR(1) Support @@ -44,9 +70,9 @@ Bison News default. You can specify the type of parser tables in the grammar file with these directives: - %define lr.type "LALR" - %define lr.type "IELR" - %define lr.type "canonical LR" + %define lr.type lalr + %define lr.type ielr + %define lr.type canonical-lr The default reduction optimization in the parser tables can also be adjusted using `%define lr.default-reductions'. See the documentation @@ -57,21 +83,34 @@ Bison News These features are experimental. More user feedback will help to stabilize them. -** %define can now be invoked via the command line. +** Unrecognized %code qualifiers are now an error not a warning. + +** %define improvements. + +*** Unrecognized variables are now an error not a warning. + +*** Multiple invocations for any variable is now an error not a warning. - Each of these bison command-line options +*** Can now be invoked via the command line. - -D NAME=VALUE - --define=NAME=VALUE + Each of these command-line options + + -D NAME[=VALUE] + --define=NAME[=VALUE] + + -F NAME[=VALUE] + --force-define=NAME[=VALUE] is equivalent to this grammar file declaration - %define NAME "VALUE" + %define NAME ["VALUE"] - for any NAME and VALUE. Omitting `=VALUE' on the command line is - equivalent to omitting `"VALUE"' in the declaration. + except that the manner in which Bison processes multiple definitions + for the same NAME differs. Most importantly, -F and --force-define + quietly override %define, but -D and --define do not. For further + details, see the section "Bison Options" in the Bison manual. -** %define variables renamed. +*** Variables renamed. The following %define variables @@ -86,7 +125,18 @@ Bison News The old names are now deprecated but will be maintained indefinitely for backward compatibility. -** Symbols names +*** Values no longer need to be quoted in grammar file. + + If a %define value is an identifier, it no longer needs to be placed + within quotations marks. For example, + + %define api.push-pull "push" + + can be rewritten as + + %define api.push-pull push + +** Symbol names. Consistently with directives (such as %error-verbose) and variables (e.g. push-pull), symbol names may include dashes in any position, @@ -115,8 +165,32 @@ Bison News about a missing semicolon where it did not before. Future releases of Bison will cease to append semicolons entirely. +** Character literals not of length one. + + Previously, Bison quietly converted all character literals to length + one. For example, without warning, Bison interpreted the operators in + the following grammar to be the same token: + + exp: exp '++' + | exp '+' exp + ; + + Bison now warns when a character literal is not of length one. In + some future release, Bison will report an error instead. + +** Verbose error messages fixed for nonassociative tokens. + + When %error-verbose is specified, syntax error messages produced by + the generated parser include the unexpected token as well as a list of + expected tokens. Previously, this list erroneously included tokens + that would actually induce a syntax error because conflicts for them + were resolved with %nonassoc. Such tokens are now properly omitted + from the list. + * Changes in version 2.4.2 (????-??-??): +** Detection of GNU M4 1.4.6 or newer during configure is improved. + ** %code is now a permanent feature. A traditional Yacc prologue directive is written in the form: @@ -140,6 +214,12 @@ Bison News Bison's Java feature as a whole including its current usage of %code is still considered experimental. +** Internationalization. + + Fix a regression introduced in Bison 2.4: Under some circumstances, + message translations were not installed although supported by the + host system. + * Changes in version 2.4.1 (2008-12-11): ** In the GLR defines file, unexpanded M4 macros in the yylval and yylloc