TITLE ^

PGE::P6Grammar.pir - compile a Perl 6 grammar

DESCRIPTION ^

This module defines the "PGE::P6Grammar" compiler, which can be used to compile complete sets of rules (grammars). Input to the grammar compiler is a string containing statements of the form

    grammar <name> ;
    rule <ident> { <p6rule> } ;
    # comment

A grammar statement indicates where to load any subsequent rules. Unlike Perl 6, there can be multiple grammar statements in the string.

Here's a code snippet to load a set of rules using the grammar compiler:

    load_bytecode "PGE.pbc"
    load_bytecode "PGE/P6Grammar.pir"

    $S0 = <<'END'
        grammar PGE::Rule;
        rule ident { [ _ | <?alpha> ] \w* }
        rule name { <ident> [ \:\: <ident> ]* }
    END
    $P0 = compreg "PGE::P6Grammar"
    (code, onload) = $P0($S0)
    # rules <PGE::Rule::ident> and <PGE::Rule::name> have now been loaded

The return value from the compiler is a string containing the PIR generated from the rules in the grammar, and code for generating any classes defined by the grammar. This code can be used to generate precompiled .pbc files for other packages.

Functions ^

__onload()

Generates the grammar parse rule needed to parse grammar strings.

compile_rules(STR src)

Compiles and loads a sequence of rule statements from the string given by src.


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