apg-js-examples/src/apg-exp/testonly.js

Examples of using the suite of apg-js applications and libraries.

/*  *************************************************************************************
 *   copyright: Copyright (c) 2021 Lowell D. Thomas, all rights reserved
 *     license: BSD-2-Clause (https://opensource.org/licenses/BSD-2-Clause)
 *   ********************************************************************************* */
// Just for completeness, this module demonstrates the `test()` function.
// It simply returns `true` if the phrase is found or `false` otherwise.
// It ignores the `u` and `d` flags but honors the `g` and `y` flags.
(function test() {
  try {
    const { apgExp: ApgExp } = require('apg-js');

    let grammar = '';
    let exp;
    let flags;
    let result;
    let str;
    let count;
    // Demonstrate with some simple tests.
    grammar += 'rule = "abc"\n';
    exp = new ApgExp(grammar, flags);
    console.log();
    console.log('Demonstrate the test function.');
    console.log();
    console.log(`grammar: ${exp.source}`);
    str = 'abc';
    result = exp.test(str);
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${result}`);
    str = '---abc---';
    result = exp.test(str);
    console.log();
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${result}`);
    str = '---a-bc---';
    result = exp.test(str);
    console.log();
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${result}`);
    // Demonstrate with the `u` and `d` flags.
    flags = 'ud';
    str = 'xyzabc>>>';
    exp = new ApgExp(grammar, flags);
    result = exp.test(str);
    console.log();
    console.log('       : test() ignores the u and d flags');
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${result}`);
    str = '---a-bc---';
    result = exp.test(str);
    console.log();
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${result}`);
    // Demonstrate with the `g` flag.
    flags = 'g';
    str = '---abc---abc---';
    exp = new ApgExp(grammar, flags);
    count = 0;
    const TRUE = true;
    while (TRUE) {
      result = exp.test(str);
      if (result === false) {
        break;
      }
      count += 1;
    }
    console.log();
    console.log('       : test() honors the g flag');
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${count > 0}`);
    console.log(`# found: ${count}`);
    // Demonstrate with the `y` flag.
    flags = 'y';
    str = '---abc---abc---';
    exp = new ApgExp(grammar, flags);
    count = 0;
    while (TRUE) {
      result = exp.test(str);
      if (result === false) {
        break;
      }
      count += 1;
    }
    console.log();
    console.log('       : test() honors the y flag');
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${count > 0}`);
    console.log(`# found: ${count}`);
    str = 'abcabc';
    count = 0;
    while (TRUE) {
      result = exp.test(str);
      if (result === false) {
        break;
      }
      count += 1;
    }
    console.log();
    console.log(`  flags: '${exp.flags}'`);
    console.log(`  input: ${str}`);
    console.log(`   test: ${count > 0}`);
    console.log(`# found: ${count}`);
  } catch (e) {
    console.log(`EXCEPTION: ${e.message}`);
  }
})();