feat(isc): allow whitespace inside ref(N), better description multiline

Author: ronaldtse

exe/codemod-imp-to-isc

@@ -213,18 +213,23 @@ module Interscript
             @out << "\n#{indent}}"
           elsif @scanner.scan(/(?:\A|\n)([ \t]+)description[ \t]*:[ \t]*\n[ \t]+/)
             # `description:` with value on subsequent indented line(s).
-            # Capture as brace block with raw text.
+            # Capture as brace block with raw text. Continues until dedent
+            # back to indent level or close brace.
             indent = @scanner[1]
             @out << "\n#{indent}description { "
             # Read until dedent or close brace
             until @scanner.eos?
-              if @scanner.check(/\n[ \t]{0,#{indent.length}}\S/) || @scanner.check(/\n[ \t]{0,#{indent.length}}\}/)
+              if @scanner.check(/\n(?:[ \t]*\n)*([ \t]{0,#{indent.length}}\S)/) ||
+                 @scanner.check(/\n(?:[ \t]*\n)*[ \t]{0,#{indent.length}}\}/)
                 @out << " }"
                 break
               elsif @scanner.scan(/[^\n]+/)
                 @out << @scanner.matched
               elsif @scanner.scan(/\n[ \t]+/)
                 @out << " "
+              elsif @scanner.scan(/\n[ \t]*\n/)
+                # Blank line — preserve as space
+                @out << " "
               elsif @scanner.scan(/\n/)
                 @out << " "
               else

lib/interscript/isc/grammar/concerns/items.rb

@@ -91,7 +91,9 @@ module Items
 
           # ref(N) — reference to Nth capture group. Only valid in `to` position.
           rule(:capture_reference) do
-            (str("ref") >> str("(") >> match(/[0-9]/).as(:digit) >> str(")")).as(:ref)
+            (str("ref") >> str("(") >> whitespace? >>
+              match(/[0-9]/).as(:digit) >> whitespace? >>
+              str(")")).as(:ref)
           end
 
           rule(:keyword) do