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Matching a specific number of occurrences of a pattern
Prerequisite Concepts

OmniMark provides three basic occurrence indicators for patters: "+" means one or more times, "*" means zero or more times, and "?" means zero or one times. But what if you want to specify a particular number of times that a pattern may repeat? Suppose, for instance, that you wanted to find all the six-letter words in a document. You could do this:

  macro wordbreak is [".,:;%"!()[]{}" or white-space] macro-end
  find wordbreak
       (letter letter letter letter letter letter) =>six
       wordbreak

     output six || "%n"

But it would be much clearer to use a numeric occurrence indicator like this:

  macro wordbreak is [".,:;%"!()[]{}" or white-space] macro-end
  find wordbreak
       (letter{6}) =>found
       wordbreak

     output found || "%n"

You can specify a range. This code will find words of between six and eight letters:

  macro wordbreak is [".,:;%"!()[]{}" or white-space] macro-end
  find wordbreak
       (letter{6 to 8}) =>found
       wordbreak

     output found || "%n"

And you can use "+" to mean "or more" so that the following code matches words of seven or more letters:

  macro wordbreak is [".,:;%"!()[]{}" or white-space] macro-end
  find wordbreak
       (letter{7}+) =>found
       wordbreak

     output found || "%n"

Note that these numeric occurrence indicators are just generalizations of the repetition and optionality indicators:

• "P?" is equivalent to "P{0 to 1}"
• "P+" is equivalent to "P{1}+"
• "P*" is equivalent to "P{0}+"

Prerequisite Concepts      Pattern matching    Repetition and optionality

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