<!DOCTYPE html><html lang='en'><head><title>[re.def]</title><meta charset='UTF-8'/><link rel='stylesheet' type='text/css' href='14882.css'/><link rel='stylesheet' type='text/css' href='expanded.css' title='Notes and examples expanded'/><link rel='alternate stylesheet' type='text/css' href='colored.css' title='Notes and examples colored'/><link rel='alternate stylesheet' type='text/css' href='collapsed.css' title='Notes and examples collapsed'/><link rel='icon' href='icon.png'/></head><body><div class='wrapper'><h1 ><a class='secnum' style='min-width:73pt'>29</a> Regular expressions library <a class='abbr_ref' href='./#re'>[re]</a></h1><h2 ><a class='secnum' style='min-width:88pt'>29.2</a> Definitions <a class='abbr_ref'>[re.def]</a></h2><div class='para' id='1'><div class='marginalizedparent'><a class='marginalized' href='#1'>1</a></div><div class='sourceLinkParent'><a class='sourceLink' href='https://github.com/Eelis/draft73ca144c7e48612fe72742f9f6a5ec9ad6a934d2/source/regex.tex#L40'>#</a></div><div id='1.sentence-1' class='sentence'>The following definitions shall apply to this Clause:<span class='indexparent'><a class='index' id=':collating_element'></a></span><span class='indexparent'><a class='index' id=':locale'></a></span></div></div><div id='defns.regex.collating.element' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.collating.element' style='min-width:103pt'>29.2.1</a><a class='abbr_ref' href='defns.regex.collating.element'>[defns.regex.collating.element]</a><div style='height:4pt'></div>collating element</h4><div id='defns.regex.collating.element-sentence-1' class='sentence'>a sequence of one or more characters within the
current locale that collate as if they were a single character<a class='hidden_link' href='#defns.regex.collating.element-sentence-1'>.</a></div> <span class='indexparent'><a class='index' id=':finite_state_machine'></a></span></div><div id='defns.regex.finite.state.machine' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.finite.state.machine' style='min-width:103pt'>29.2.2</a><a class='abbr_ref' href='defns.regex.finite.state.machine'>[defns.regex.finite.state.machine]</a><div style='height:4pt'></div>finite state machine</h4><div id='defns.regex.finite.state.machine-sentence-1' class='sentence'>an unspecified data structure that is used to
represent a regular expression, and which permits efficient matches
against the regular expression to be obtained<a class='hidden_link' href='#defns.regex.finite.state.machine-sentence-1'>.</a></div> <span class='indexparent'><a class='index' id=':format_specifier'></a></span></div><div id='defns.regex.format.specifier' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.format.specifier' style='min-width:103pt'>29.2.3</a><a class='abbr_ref' href='defns.regex.format.specifier'>[defns.regex.format.specifier]</a><div style='height:4pt'></div>format specifier</h4><div id='defns.regex.format.specifier-sentence-1' class='sentence'>a sequence of one or more characters that is to be
replaced with some part of a regular expression match<a class='hidden_link' href='#defns.regex.format.specifier-sentence-1'>.</a></div> <span class='indexparent'><a class='index' id=':matched'></a></span><span class='indexparent'><a class='index' id=':regular_expression,matched'></a></span></div><div id='defns.regex.matched' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.matched' style='min-width:103pt'>29.2.4</a><a class='abbr_ref' href='defns.regex.matched'>[defns.regex.matched]</a><div style='height:4pt'></div>matched</h4><div id='defns.regex.matched-sentence-1' class='sentence'>a sequence of zero or more characters is matched by
a regular expression when the characters in the sequence
correspond to a sequence of characters defined by the pattern<a class='hidden_link' href='#defns.regex.matched-sentence-1'>.</a></div> <span class='indexparent'><a class='index' id=':primary_equivalence_class'></a></span><span class='indexparent'><a class='index' id=':locale_'></a></span></div><div id='defns.regex.primary.equivalence.class' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.primary.equivalence.class' style='min-width:103pt'>29.2.5</a><a class='abbr_ref' href='defns.regex.primary.equivalence.class'>[defns.regex.primary.equivalence.class]</a><div style='height:4pt'></div>primary equivalence class</h4><div id='defns.regex.primary.equivalence.class-sentence-1' class='sentence'>a set of one or more characters which
share the same primary sort key: that is the sort key weighting that
depends only upon character shape, and not accents, case, or
locale specific tailorings<a class='hidden_link' href='#defns.regex.primary.equivalence.class-sentence-1'>.</a></div></div><div id='defns.regex.regular.expression' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.regular.expression' style='min-width:103pt'>29.2.6</a><a class='abbr_ref' href='defns.regex.regular.expression'>[defns.regex.regular.expression]</a><div style='height:4pt'></div>regular expression</h4><div id='defns.regex.regular.expression-sentence-1' class='sentence'>a pattern that selects specific strings
from a set of character strings<a class='hidden_link' href='#defns.regex.regular.expression-sentence-1'>.</a></div> <span class='indexparent'><a class='index' id=':sub-expression,regular_expression'></a></span></div><div id='defns.regex.subexpression' class='section'><h4 style='margin-bottom:3pt'><a class='secnum' href='#defns.regex.subexpression' style='min-width:103pt'>29.2.7</a><a class='abbr_ref' href='defns.regex.subexpression'>[defns.regex.subexpression]</a><div style='height:4pt'></div>sub-expression</h4><div id='defns.regex.subexpression-sentence-1' class='sentence'>a subset of a regular expression that has
been marked by parenthesis<a class='hidden_link' href='#defns.regex.subexpression-sentence-1'>.</a></div></div></div></body></html>