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* examples/c/bistromathic/parse.y (user_context): We need the current line. (yyreport_syntax_error): Quote the guilty line, with squiggles. * examples/c/bistromathic/bistromathic.test: Adjust.
50 lines
1.8 KiB
Markdown
50 lines
1.8 KiB
Markdown
# bistromathic - all the bells and whistles
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This example demonstrates best practices when using Bison.
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- Its hand-written scanner tracks locations.
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- Its interface is pure.
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- It uses %params to pass user information to the parser and scanner.
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- Its scanner uses the `error` token to signal lexical errors and enter
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error recovery.
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- Its interface is "incremental", well suited for interaction: it uses the
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push-parser API to feed the parser with the incoming tokens.
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- It features an interactive command line with completion based on the
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parser state, based on `yyexpected_tokens`.
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- It uses Bison's standard catalogue for internationalization of generated
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messages.
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- It uses a custom syntax error with location, lookahead correction and
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token internationalization.
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- Error messages quote the source with squiggles that underline the error:
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```
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> 123 456
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1.5-7: syntax error: expected end of file or + or - or * or / or ^ before number
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1 | 123 456
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| ^~~
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```
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- It supports debug traces with semantic values.
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- It uses named references instead of the traditional $1, $2, etc.
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To customize the interaction with bistromathic, see the GNU Readline user
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manual (see `info rluserman`).
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<!---
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Local Variables:
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fill-column: 76
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ispell-dictionary: "american"
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End:
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Copyright (C) 2020 Free Software Foundation, Inc.
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This file is part of Bison, the GNU Compiler Compiler.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.3 or
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any later version published by the Free Software Foundation; with no
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Invariant Sections, with no Front-Cover Texts, and with no Back-Cover
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Texts. A copy of the license is included in the "GNU Free
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Documentation License" file as part of this distribution.
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LocalWords: bistromathic yyexpected lookahead ispell american
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LocalWords: MERCHANTABILITY
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--->
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