weyland 0.0.8

An alternative way to write regular expression and a lexer using them.

Weyland

Weyland provides an alternative way to write regular expression (regex) and a lexer using them.

Syntax of regular expression

In Weyland, we call regular expression rex instead of regex to differenciate them.

Sequence

ab means a then b

Choice

[ab] means a or b

Option and repetition

• a?b means b or ab (a is optionnal, it can appear between 0 and 1 time),
• a+b means ab, aab, aaab, aaaab, etc. (a is mandatory, it must appear betweean 1 and X times),
• a*b means b, ab, aab, aaab, aaaab, etc. (a is optionnal, it can appear between 0 and X times).

Special chararacters

• # means any digits
• @ means any letters
• $ means any digits, letters and the underscore character (_)
• . means any characters which is not a new line

Limitations

• In a choice, you can only choose between one element not between sequences,
• In a choice, no repeated element nor optionnal element.

Languages available

• A set of tokens is available for the languages: bnf, json, lua python and hamill.