You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
pegjs/lib/compiler/passes/report-undefined-rules.js

44 lines
875 B
JavaScript

"use strict";
const GrammarError = require( "../../grammar-error" );
const asts = require( "../asts" );
const visitor = require( "../visitor" );
// Checks that all referenced rules exist.
function reportUndefinedRules( ast, options ) {
const check = visitor.build( {
rule_ref( node ) {
if ( ! asts.findRule( ast, node.name ) ) {
throw new GrammarError(
`Rule "${ node.name }" is not defined.`,
node.location
);
}
}
} );
check( ast );
if ( options.allowedStartRules ) {
options.allowedStartRules.forEach( rule => {
if ( ! asts.findRule( ast, rule ) ) {
throw new GrammarError( `Start rule "${ rule }" is not defined.` );
}
} );
}
}
module.exports = reportUndefinedRules;