-# Format:
-# NAME \t TYPE, arg-description [num-args] [longjump-len] \t DESCRIPTION
-
-# Empty rows and #-comment rows are ignored.
-
-# Exit points
-END END, no End of program.
-SUCCEED END, no Return from a subroutine, basically.
-
-# Anchors:
-BOL BOL, no Match "" at beginning of line.
-MBOL BOL, no Same, assuming multiline.
-SBOL BOL, no Same, assuming singleline.
-EOS EOL, no Match "" at end of string.
-EOL EOL, no Match "" at end of line.
-MEOL EOL, no Same, assuming multiline.
-SEOL EOL, no Same, assuming singleline.
-BOUND BOUND, no Match "" at any word boundary
-BOUNDL BOUND, no Match "" at any word boundary
-NBOUND NBOUND, no Match "" at any word non-boundary
-NBOUNDL NBOUND, no Match "" at any word non-boundary
-GPOS GPOS, no Matches where last m//g left off.
-
-# [Special] alternatives
-REG_ANY REG_ANY, no Match any one character (except newline).
-SANY REG_ANY, no Match any one character.
-CANY REG_ANY, no Match any one byte.
-ANYOF ANYOF, sv Match character in (or not in) this class.
-ALNUM ALNUM, no Match any alphanumeric character
-ALNUML ALNUM, no Match any alphanumeric char in locale
-NALNUM NALNUM, no Match any non-alphanumeric character
-NALNUML NALNUM, no Match any non-alphanumeric char in locale
-SPACE SPACE, no Match any whitespace character
-SPACEL SPACE, no Match any whitespace char in locale
-NSPACE NSPACE, no Match any non-whitespace character
-NSPACEL NSPACE, no Match any non-whitespace char in locale
-DIGIT DIGIT, no Match any numeric character
-DIGITL DIGIT, no Match any numeric character in locale
-NDIGIT NDIGIT, no Match any non-numeric character
-NDIGITL NDIGIT, no Match any non-numeric character in locale
-CLUMP CLUMP, no Match any combining character sequence
-
-# BRANCH The set of branches constituting a single choice are hooked
-# together with their "next" pointers, since precedence prevents
-# anything being concatenated to any individual branch. The
-# "next" pointer of the last BRANCH in a choice points to the
-# thing following the whole choice. This is also where the
-# final "next" pointer of each individual branch points; each
-# branch starts with the operand node of a BRANCH node.