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* examples/c++/README.md, examples/c++/calc++/README.md, * examples/c/calc/README.md, examples/c/lexcalc/README.md, * examples/c/reccalc/README.md: Prefer the GFDL banner to the GPL one.
39 lines
1.0 KiB
Markdown
39 lines
1.0 KiB
Markdown
# reccalc - recursive calculator with Flex and Bison
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In this example the generated parser is pure and reentrant: it can be used
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concurrently in different threads, or recursively. As a proof of this
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reentrancy, expressions in parenthesis are tokenized as strings, and then
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recursively parsed from the parser:
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```
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exp: STR
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{
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result r = parse_string ($1);
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free ($1);
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if (r.nerrs)
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{
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res->nerrs += r.nerrs;
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YYERROR;
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}
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else
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$$ = r.value;
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}
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```
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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) 2018-2020 Free Software Foundation, Inc.
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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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--->
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