mirror of
https://git.savannah.gnu.org/git/bison.git
synced 2026-03-11 05:13:04 +00:00
6ee1494d6e
Suuggested by Frank Heckenbach. <https://lists.gnu.org/r/bug-bison/2022-01/msg00000.html> * doc/bison.texi (Location Type): Explain why location's "column" are defined vaguely. Show tab handling in ltcalc and calc++. * examples/c/bistromathic/parse.y: Show tab handling. * examples/c++/calc++/calc++.test, * examples/c/bistromathic/bistromathic.test: Check tab handling.
bistromathic - all the bells and whistles
This example demonstrates best practices when using Bison.
- Its hand-written scanner tracks locations.
- Its interface is pure.
- It uses %params to pass user information to the parser and scanner.
- Its scanner uses the
errortoken to signal lexical errors and enter error recovery. - Its interface is "incremental", well suited for interaction: it uses the push-parser API to feed the parser with the incoming tokens.
- It features an interactive command line with completion based on the
parser state, based on
yyexpected_tokens. - It uses Bison's standard catalog for internationalization of generated messages.
- It uses a custom syntax error with location, lookahead correction and token internationalization.
- Error messages quote the source with squiggles that underline the error:
> 123 456
1.5-7: syntax error: expected end of file or + or - or * or / or ^ before number
1 | 123 456
| ^~~
- It supports debug traces with semantic values.
- It uses named references instead of the traditional $1, $2, etc.
To customize the interaction with bistromathic, see the GNU Readline user
manual (see info rluserman).