#regular-expressions code explainers

php

<?php
 
namespace App\Services;

How a password strength validator works in PHP

validation regular-expressions data-driven

Intermediate 8 steps

ruby

class SnippetHighlighter
  CONTEXT_RADIUS = 60
  MAX_TERMS = 8

Building search-result snippets in Ruby

regular-expressions text-processing search

Intermediate 9 steps

ruby

class Pluralizer
  IRREGULARS = {
    "person" => "people",
    "child" => "children",

Building an English pluralizer in Ruby

regular-expressions lookup-tables string-manipulation

Intermediate 8 steps

javascript

const UNIT_MULTIPLIERS = {
  ms: 1,
  s: 1000,
};

Parsing CSS durations into milliseconds

parsing regular-expressions validation

Intermediate 6 steps

ruby

module Dotenv
  LINE = /\A\s*(?:export\s+)?([A-Za-z_][A-Za-z0-9_]*)\s*=\s*(.*?)\s*\z/
 
  module_function

Parsing a .env file in Ruby

parsing regular-expressions environment-variables

Intermediate 8 steps

python

import re
from dataclasses import dataclass, field

Building a table of contents from Markdown

regular-expressions parsing slugification

Intermediate 9 steps

ruby

require "yaml"
 
class FrontMatter
  DELIMITER = /\A---\s*\n(.*?)\n---\s*\n?(.*)\z/m

Parsing YAML front matter in Ruby

parsing regular-expressions yaml

Intermediate 8 steps

javascript

const FRONTMATTER_RE = /^---\r?\n([\s\S]*?)\r?\n---\r?\n?/;
 
function coerce(value) {
  const trimmed = value.trim();

Parsing YAML-style frontmatter in JavaScript

parsing regular-expressions type-coercion

Intermediate 9 steps

typescript

type Semver = {
  major: number;
  minor: number;
  patch: number;

Parsing and comparing semver strings in TypeScript

parsing regular-expressions comparison

Intermediate 9 steps

javascript

const TOKEN_SPECS = [
  ["comment", /^\/\/[^\n]*|^\/\*[\s\S]*?\*\//],
  ["string", /^"(?:\\.|[^"\\])*"|^'(?:\\.|[^'\\])*'|^`(?:\\.|[^`\\])*`/],
  ["number", /^0[xX][\da-fA-F]+|^\d+(?:\.\d+)?(?:[eE][+-]?\d+)?/],

Building a syntax highlighter tokenizer

tokenizer regular-expressions lexing

Intermediate 8 steps

php

<?php
 
namespace App\Support;

Normalizing phone numbers to E.164 in PHP

input-validation normalization regular-expressions

Intermediate 8 steps

ruby

class DurationParser
  UNIT_SECONDS = {
    'w' => 604_800,
    'd' => 86_400,

Parsing duration strings into seconds in Ruby

parsing regular-expressions validation

Intermediate 7 steps