Revision history for Switch-Declare

0.01    2026-06-12
        First release.
        - `switch (EXPR) { case PAT { ... } ... default { ... } }` as a real
          lexical pragma, recognised only within `use Switch::Declare` scope.
        - Compile-time keyword plugin; the construct lowers to a native
          conditional expression. No source filter, no smartmatch, no CPAN
          dependencies (core perl 5.14+ only).
        - Pattern kinds: number (==), string (eq), regex /.../imsx, range
          [LO..HI], list [a,b,c] membership, and predicates - either \&name
          (also package-qualified, \&Pkg::name) or an inline sub { ... } that
          closes over the enclosing lexicals. Each lowers to native ops (regex
          compiles to a real OP_MATCH at compile time); there are no runtime
          helper subs.
        - Statement and expression (value-returning) forms; usable infix.
        - Scrutinee evaluated exactly once; first matching case wins; optional
          trailing default.
        - Fast path: a plain variable/constant scrutinee with single-expression
          arms compiles to exactly a hand-written if/elsif chain (0-2% in the
          bundled benchmark).
        - Dispatch mode: a string-keyed lookup table (>= 4 arms, constant
          values) compiles to a single O(1) hash lookup against a compile-time
          hash - ~2.5x faster than the if/elsif chain at 20 arms. Chosen
          automatically; never changes behaviour.
