Ruby patterns

Caveat: string matching is limited to quoted strings, %Q/.../, %Q(...), %q/.../ and %q(...). The latter forms could be matched more generally using back references (not yet supported) and lazy quantifiers, using regex %q(.).*?\1.

• classes matches class definition lines
• comments matches comments
• defs matches function definition lines
• modules matches module lines
• names matches identifiers (and keywords) not inside strings and comments
• strings matches strings
• zap_comments removes comments from matches
• zap_strings removes strings from matches