| @c -*-texinfo-*- |
| @c This is part of the GNU Guile Reference Manual. |
| @c Copyright (C) 1996, 1997, 2000, 2001, 2002, 2003, 2004, 2007, 2009, 2010, 2017 |
| @c Free Software Foundation, Inc. |
| @c See the file guile.texi for copying conditions. |
|
|
| @node LALR(1) Parsing |
| @section LALR(1) Parsing |
|
|
| The @code{(system base lalr)} module provides the |
| @uref{https://github.com/schemeway/lalr-scm/, @code{lalr-scm} LALR(1) parser |
| generator by Dominique Boucher}. @code{lalr-scm} uses the same algorithm as GNU |
| Bison (@pxref{Introduction, Introduction to Bison,, bison, Bison@comma{} The |
| Yacc-compatible Parser Generator}). Parsers are defined using the |
| @code{lalr-parser} macro. |
|
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| @deffn {Scheme Syntax} lalr-parser [@var{options}] @var{tokens} @var{rules}... |
| Generate an LALR(1) syntax analyzer. @var{tokens} is a list of symbols |
| representing the terminal symbols of the grammar. @var{rules} are the grammar |
| production rules. |
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| Each rule has the form @code{(@var{non-terminal} (@var{rhs} ...) : @var{action} |
| ...)}, where @var{non-terminal} is the name of the rule, @var{rhs} are the |
| right-hand sides, i.e., the production rule, and @var{action} is a semantic |
| action associated with the rule. |
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| The generated parser is a two-argument procedure that takes a |
| @dfn{tokenizer} and a @dfn{syntax error procedure}. The tokenizer |
| should be a thunk that returns lexical tokens as produced by |
| @code{make-lexical-token}. The syntax error procedure may be called |
| with at least an error message (a string), and optionally the lexical |
| token that caused the error. |
| @end deffn |
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| Please refer to the @code{lalr-scm} documentation for details. |
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