1 Introduction

      1.1 Prior work

    2 Interface

      2.1 Syntax

      2.2 Matching

      2.3 Compiling

    3 Linting and warnings

      3.1 Unreachability

        3.1.1 "This expression is impossible to match."

        3.1.2 "The <n-th> group in this expression is impossible to match."

      3.2 Matching too much

        3.2.1 "This expression matches the empty string at every position."

        3.2.2 "This expression will only ever match the empty string at every position."

      3.3 Syntax errors

      3.4 Type errors

        3.4.1 "This regular expression only produces <m> registers, but <n> variables were provided."

        3.4.2 SBCL reports a type conflict

    4 Differences between POSIX and PCRE regexen

      4.1 The longest match wins

      4.2 The longest submatch wins

    Bibliography

    Index