This project allows for translation between grep style regex strings and the regular expression data type utilized by 15-150.

Syntax

Any single character, e.g., a will match that character. To match a literal version of a meta-character escape it with backslash, e.g., \* will match the character *. Adjacent characters are treated as the concatenation of those characters.

Characters can be grouped for other commands with parentheses ((, )).

Any atom (either a single character or characters grouped by parentheses) followed by a * will be matched 0 or more times.

Two atoms can be alternatively matched with |. For instance a|b would match either a or b.

Examples

• a will match the single character a
• a|b will match either the single character a or the single character b
• a* will match a 0 or more times
• abc will match the string abc
• (ab)*c will match ab 0 or more times followed by c
• a|b* will match either:
  • a; or,
  • b 0 or more times

License

MIT

Authors

Code for parsing regular expression in string format into the internal datatype was written by Cooper Pierce and James Gallicchio.

Code which utilizes Regex.t values to match and accept regex was written by 15-150 course staff, including Michael Erdmann and Frank Pfenning