apg-js-examples
Version:
Examples of using the suite of apg-js applications and libraries.
74 lines (72 loc) • 3.05 kB
JavaScript
/* *************************************************************************************
* copyright: Copyright (c) 2021 Lowell D. Thomas, all rights reserved
* license: BSD-2-Clause (https://opensource.org/licenses/BSD-2-Clause)
* ********************************************************************************* */
// Demonstration of using User-Defined Terminals (UDTs).
// That is, hand-written code snippets for matching specific phrases.
module.exports = function main(args) {
/* display the program arguments */
console.log('udt args');
console.dir(args);
/* the help screen */
let desc = '';
desc += 'The "udt" example demonstrates the use of User-Defined Terminals (UDTs)\n';
desc += 'in the SABNF grammar.\n';
desc += 'Examine or run a debugger on this module,\n';
desc += '"apg-js-examples/src/udt/main.js", to study the example.\n';
let help = '';
help += 'Usage: npm run udt [-- arg]\n';
help += ' arg: help (or no arg) to display this help screen.\n';
help += ' minimal minimal procedures for setting up a parser for a grammar with UDTs\n';
help += ' stats minimal with statistics generated\n';
help += ' trace minimal with trace generated\n';
help += ' parent parent-mode back referencing of UDT\n';
help += ' universal universal-mode back referencing of UDT\n';
help += ' all run all demonstrations\n';
if (!args[0]) {
/* display the help screen and exit */
console.log(desc);
console.log(help);
return;
}
switch (args[0]) {
case 'help':
console.log(help);
return;
case 'minimal':
console.log('\nDemonstrate: minimal procedures for setting up a parser for a grammar with UDTs');
require('./minimal');
break;
case 'stats':
console.log('\nDemonstrate: minimal with statistics generated');
require('./stats');
break;
case 'trace':
console.log('\nDemonstrate: inimal with trace generated');
require('./trace');
break;
case 'parent':
console.log('\nDemonstrate: arent-mode back referencing of UDT');
require('./parent')();
break;
case 'universal':
console.log('\nDemonstrate: universal-mode back referencing of UDT');
require('./universal')();
break;
case 'all':
console.log('\nDemonstrate: minimal procedures for setting up a parser for a grammar with UDTs');
require('./minimal');
console.log('\nDemonstrate: minimal with statistics generated');
require('./stats');
console.log('\nDemonstrate: inimal with trace generated');
require('./trace');
console.log('\nDemonstrate: parent-mode back referencing of UDT');
require('./parent')();
console.log('\nDemonstrate: universal-mode back referencing of UDT');
require('./universal')();
break;
default:
console.log(`unrecognized argument: ${args[0]}`);
console.log(help);
}
};