/usr/share/source-highlight/ruby.lang is in libsource-highlight-common 3.1.8-1.2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | preproc = "require"
include "number.lang"
string delim "\"" "\"" escape "\\"
string delim "'" "'" escape "\\"
string delim "<" ">"
regexp = '/[^\n]*/'
(symbol,regexp) = `(%r)(\{(?:\\\}|#\{[[:alnum:]]+\}|[^}])*\})`
keyword = "alias|begin|BEGIN|break|case|defined|do|else|elsif|end|END|ensure|for|if|in|include|loop|next|raise|redo|rescue|retry|return|super|then|undef|unless|until|when|while|yield|false|nil|self|true|__FILE__|__LINE__|and|not|or|def|class|module|catch|fail|load|throw"
comment delim '(^\=begin)' '^(\=end)' multiline
type = '(\$[#]?|@@|@)([[:word:]]+|\'|\"|/)'
# don't highlight ? and ! as symbols if they are part of a method call
normal = '[[:alnum:]]+(\?|!)'
include "symbols.lang"
# for variable interpolation, #{ is not a comment
(symbol,cbracket) = `(#)(\{)`
include "script_comment.lang"
cbracket = "{|}"
# no function highlighting for Ruby, since a method invocation
# can be written even without parenthesis
# include "function.lang"
|