SRFI 264: String Syntax for Scheme Regular Expressions

by Sergei Egorov

status: draft (2025-07-25)

keywords: Pattern Matching

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Abstract

This SRFI proposes SSRE, an alternative string-based syntax for Scheme Regular Expressions as defined by SRFI 115. String syntax is both compact and familiar to many regexp users; it is translated directly into SRE S-expressions, providing equivalent constructs. While the proposed syntax mostly follows PCRE, it takes into account specifics of Scheme string syntax and limitations of SRE, leaving out constructs that either duplicate functionality provided by Scheme strings or have no SRE equivalents. The repertoire of named sets and boundary conditions can be extended via a parameter mechanism. Extensions to PCRE syntax allow concise expression of operations on named character sets.