TACTweb Queries: Regular Expressions

Regular Expressions can be specified (a) as a source in a selection criteria statement, (b) as a refinement, or (c) as a part of a WHEN selection. In the first two instances it selects word types in the last case it selects values for structural references.

Format is a string of letters or diacritics with special characters that have special meanings interspersed. In the following, the term "word letter" means letter or diacritic. Special characters are:

• ".": Means "any word letter"
• "[...]": Means "any one of the word letters between the brackets": e.g. "[aeiou]" means "any vowel". If an alphabetically consecutive set of letters is desired, use the range selector ":" -- [a:e] means all letters between "a" and "e".
• "[~...]": Means "any word letter BUT the word letters between the brackets": e.g. "[~aeiou]" means "any letter BUT a vowel".
• "*": Means "zero or more occurrences of the PRECEDING word letter". e.g.

  e*

  means "zero or more occurrences of the word letter 'e'",

  .*

  means "zero or more occurrences of any word letter",

  [ae]*

  means "zero or more occurrences of either the letter "e" or "a".

• "\": Means "treat the following character as a letter or diacritic in a regular expression."

Some examples

b.t

Any three-letter word beginning with the letter "b" and ending with the letter "t".

b.*t

Any word of any length beginning with the letter "b" and ending with "t".

ba...

Any five letter word beginning with the sequence "ba".

.[bt].

Any three-letter word containing, as the middle letter, the letter "b" or "t".

[~bt].

Any three-letter word containing, as the middle letter, any letter BUT the letters "b" or "t".

.*b.*

Any word containing the letter "b" in any position.

.*ing

Any word ending with the letter sequence "ing".

.*lov.*

Any word containing the letter sequence "lov".

Web design Alex Stevens, content Geoffrey Rockwell or John Bradley. March 7, 1997