lib/vendor/sexpistol/sexpistol/sexpistol_parser.rb in qcmd-0.1.13 vs lib/vendor/sexpistol/sexpistol/sexpistol_parser.rb in qcmd-0.1.14

@@ -1,14 +1,18 @@
 require 'strscan'
 
+class ParseException < Exception
+end
+
 class SexpistolParser < StringScanner
 
   def initialize(string)
     # step through string counting closing parens, exclude parens in string literals
     in_string_literal = false
     escape_char = false
     paren_count = 0
+
     string.bytes.each do |byte|
       if escape_char
         escape_char = false
         next
       end
@@ -29,35 +33,35 @@
         in_string_literal = !in_string_literal
       end
     end
 
     if paren_count > 0
-      raise Exception, "Missing closing parentheses"
+      raise ParseException.new("Missing closing parentheses")
     elsif paren_count < 0
-      raise Exception, "Missing opening parentheses"
+      raise ParseException.new("Missing opening parentheses")
     end
 
     super(string)
   end
 
   def parse
     exp = []
     while true
       case fetch_token
-        when '('
-          exp << parse
-        when ')'
-          break
-        when :"'"
-          case fetch_token
-          when '(' then exp << [:quote].concat([parse])
-          else exp << [:quote, @token]
-          end
-        when String, Fixnum, Float, Symbol
-          exp << @token
-        when nil
-          break
+      when '('
+        exp << parse
+      when ')'
+        break
+      when :"'"
+        case fetch_token
+        when '(' then exp << [:quote].concat([parse])
+        else exp << [:quote, @token]
+        end
+      when String, Fixnum, Float, Symbol
+        exp << @token
+      when nil
+        break
       end
     end
     exp
   end
 
@@ -71,14 +75,14 @@
       matched
     # Match a string literal
     elsif scan(/"([^"\\]|\\.)*"/)
       eval(matched)
     # Match a float literal
-    elsif scan(/[\-\+]? [0-9]+ ((e[0-9]+) | (\.[0-9]+(e[0-9]+)?))(\)| )(\s|$)/x)
+    elsif scan(/[\-\+]? [0-9]+ ((e[0-9]+) | (\.[0-9]+(e[0-9]+)?))#{ expression_ender }/x)
       matched.to_f
     # Match an integer literal
-    elsif scan(/[\-\+]?[0-9]+(\)| )(\s|$)/x)
+    elsif scan(/[\-\+]?[0-9]+#{ expression_ender }/)
       matched.to_i
     # Match a comma (for comma quoting)
     elsif scan(/'/)
       matched.to_sym
     # Match a symbol
@@ -87,8 +91,16 @@
     # If we've gotten here then we have an invalid token
     else
       near = scan %r{.{0,20}}
       raise "Invalid character at position #{pos} near '#{near}'."
     end
+  end
+
+  def expression_ender
+    # end Fixnum and Float matchers with a non-grouping positive lookahead
+    # assertion that matches a closing paren, whitespace, or string end.  The
+    # positive lookahead (?=...) ensures the string scanner includes the ending
+    # character in next fetch_token call.
+    '(?=(?:\)|\s|$))'
   end
 
 end