Regular Impressions

• Simplified email pattern

  start
    repeat anyof :alphanumeric: + _ . - 1 to inf
    @
    repeat anyof :alphanumeric: . - 1 to inf
  end

• Negative, whole, or decimal numbers

  start
    repeat - 0 to 1
    repeat :digit: 0 to inf
    repeat . 0 to 1
    repeat :digit: 1 to inf
  end

• URL pattern

  start
    http
    repeat s 0 to 1
    ://
    repeat www. 0 to 1
    repeat anyof - :alphanumeric: @ : % . _ \ + ~ # = 2 to 256
    .
    repeat :lowercase: 2 to 6
    :boundary:
    repeat anyof - :alphanumeric: @ : % . _ \ + ~ # ( ) ? / = 0 to inf
  end

• Password with 1 lowercase letter, 1 uppercase letter, 1 number, and contains at least 8 characters

  :null: ifnextis repeat :any: 0 to inf and :digit:
  :null: ifnextis repeat :any: 0 to inf and :alphanumeric:
  :null: ifnextis repeat :any: 0 to inf and :uppercase:
  :null: ifnextis repeat :any: 0 to inf and :lowercase:
  start
    repeat :any: 8 to inf
  end

• Date in the form YYYY/MM/DD from 1900-01-01 to 2099-12-31

  start
    comment -------YEAR
      19 or 20
      repeat :digit: 2
      /
    comment -------MONTH
      regex (
      0
      range 1 to 9
  
      or
  
      1
      anyof 0 1 2
      regex )
      /
    comment -------DATE
      regex (
      0
      range 1 to 9
  
      or
  
      anyof 1 2
      range 0 to 9
  
      or
  
      3
      anyof 0 1
      regex )
  end

Regular Impressions

Regular Impressions is a simple tool for writing regular expressions using a pseudocode-like language.

Created by Zoren Tan.

I made Regular Impressions as a side project in the summer of 2021 after finishing our course about regular expressions. This is just a proof-of-concept project created with my limited skills at that time, to demonstrate a pseudocode-like language as an alternative to writing and storing regular expressions.

Regular Impressions is built with the help of CodeMirror.