lib/tcl/ruby/parser.rb in tcl-ruby-0.1.0 vs lib/tcl/ruby/parser.rb in tcl-ruby-0.1.1

@@ -1,71 +1,103 @@
 require 'strscan'
 
 module Tcl
   module Ruby
     class Interpreter
+      EX_CHAR_CHECK = lambda do |s, t|
+        (t && !s.check(/\s|\z/)) || (!t && !s.check(/\s|\z|;/))
+      end.curry
+
       def parse(str, to_list = false)
-        s = StringScanner.new(str)
-        r = ListArray.new
-        pdepth = ddepth = bdepth = 0
-        buffer = ''
-        ret = nil
-        until s.empty?
-          if s.scan(/\\./m)
-            buffer << s[0] unless s[0][1] =~ /\s/
-          elsif !to_list && s.scan(/\r\n|\r|\n|;/)
-            if pdepth == 0 && ddepth == 0 && bdepth == 0
-              r << buffer
-              ret = command(r) unless r.empty?
-              r = ListArray.new
-            else
-              buffer << s[0]
-            end
-          elsif s.scan(/\s+/)
-            if pdepth == 0 && ddepth == 0 && bdepth == 0
-              r << buffer
-            else
-              buffer << s[0]
-            end
-          else
-            buffer <<
-              if s.scan(/{/)
-                # pdepth += 1 if ddepth == 0
-                pdepth += 1 if buffer == '' || pdepth != 0
-                s[0]
-              elsif s.scan(/}/)
-                ret = s[0] # pdepth -= 1 if ddepth == 0
-                pdepth -= 1 if pdepth != 0
-                raise(ParseError, 'extra characters after close-brace') if
-                  buffer[0] == '{' && pdepth == 0 && !s.check(/\s|\z/)
-                ret
-              elsif !to_list && s.scan(/\[/)
-                bdepth += 1 if pdepth == 0
-                s[0]
-              elsif !to_list && s.scan(/\]/)
-                bdepth -= 1 if pdepth == 0
-                s[0]
-              elsif s.scan(/"/)
-                ret = s[0]
-                ddepth = 1 - ddepth if buffer == '' || buffer[0] == '"'
-                raise(ParseError, 'extra characters after close-quote') if
-                  buffer[0] == '"' && ddepth == 0 && !s.check(/\s|\z/)
-                ret
-              elsif s.scan(/\S/)
-                s[0]
-              else
-                raise(ParseError, "parse error #{s.rest}")
-              end
+        str2 = (str + "\n").gsub(/\\\n\s*/, ' ') # replace \ & \n & extra ws
+        @s = StringScanner.new(str2)
+        @list_array = ListArray.new
+        @pstack = [] # stack for brace, bracket, quote
+        @buffer = '' # ListElement.new('')'' # buffer for list element
+        @commands = []
+        until @s.empty?
+          if @s.scan(/\\./) then @buffer << @s[0]
+          elsif @s.scan(/\#/) then parse_comments
+          elsif !to_list && @s.scan(/\r\n|\r|\n|;/) then parse_command_ends
+          elsif @s.scan(/\s/) then parse_blanks
+          elsif @s.scan(/\S/)
+            @buffer << @s[0]
+            analyze_parentheses(to_list, EX_CHAR_CHECK[@s]) if
+              @buffer.parenthesis?
           end
         end
-        r << buffer
-        raise(ParseError, 'unmatched parenthesises') if
-        ddepth != 0 || pdepth != 0 || bdepth != 0
-        if to_list
-          r.to_string
+        check_pstack
+        to_list ? @list_array.to_string : command(@commands)
+      end
+
+      private
+
+      def check_pstack
+        raise(ParseError, "unmatched #{@pstack.last}s") if @pstack.any?
+      end
+
+      def parse_command_ends
+        bl = @s[0]
+        if @pstack.empty?
+          @list_array << @buffer
+          @list_array.to_string
+          @commands << @list_array.dup
+          @list_array.clear
         else
-          ret = command(r) unless r.empty?
-          ret
+          @buffer << bl
+        end
+      end
+
+      def parse_blanks
+        @pstack.empty? ? @list_array << @buffer : @buffer << @s[0]
+      end
+
+      def parse_comments
+        if @buffer.empty? && @list_array.empty?
+          @s.scan(/.+$/)
+        else
+          @buffer << @s[0]
+        end
+      end
+
+      def matched_parentheses(id, has_ex_char)
+        if @pstack.last == id
+          r = @pstack.pop
+          if @pstack.empty? && has_ex_char
+            raise(ParseError, "extra characters after close-#{id}")
+          end
+          r
+        end
+      end
+
+      def analyze_braces(to_list, extra_characters_check)
+        if @buffer[-1] == '{'
+          @pstack.push(:brace) if @pstack.last != :quote
+        else
+          matched_parentheses(:brace, extra_characters_check[to_list])
+        end
+      end
+
+      def analyze_quotes(to_list, extra_characters_check)
+        unless matched_parentheses(:quote, extra_characters_check[to_list])
+          @pstack.push :quote if @pstack.last != :brace
+        end
+      end
+
+      def analyze_brackets
+        if @buffer[-1] == '[' && @pstack.last != :brace
+          @pstack.push :bracket
+        elsif @pstack.last == :bracket
+          @pstack.pop
+        end
+      end
+
+      def analyze_parentheses(to_list, extra_characters_check)
+        bl = @buffer[-1]
+        case bl
+        when '{', '}' then analyze_braces(to_list, extra_characters_check)
+        when '[', ']' then analyze_brackets unless to_list
+        when '"' then analyze_quotes(to_list, extra_characters_check)
         end
       end
     end
   end
 end