lib/dolos/parsers.rb in dolos-0.2.0 vs lib/dolos/parsers.rb in dolos-0.2.1

@@ -1,21 +1,22 @@
 # frozen_string_literal: true
 
 module Dolos
   module Parsers
     def string(str)
+      utf8_str = str.encode('UTF-8')
+
       Parser.new do |state|
         state.input.mark_offset
-        utf8_str = str.encode('UTF-8')
         if state.input.matches?(utf8_str)
           Success.new(utf8_str, str.bytesize)
         else
           advanced = state.input.offset
           got_error = state.input.io.string.byteslice(state.input.backup, advanced)
           state.input.rollback
           Failure.new(
-            "Expected #{str.inspect} but got #{got_error.inspect}",
+            -> { "Expected #{str.inspect} but got #{got_error.inspect}" },
             advanced,
             state
           )
         end
       end
@@ -30,11 +31,11 @@
           Success.new(matched_string, matched_string.bytesize)
         else
           advanced = state.input.offset
           state.input.rollback
           Failure.new(
-            "Expected pattern #{pattern.inspect} but got #{state.input.io.string.inspect}",
+            -> { "Expected pattern #{pattern.inspect} but got #{state.input.io.string.inspect}" },
             advanced,
             state
           )
         end
       end
@@ -50,11 +51,11 @@
           Success.new(char, char.bytesize)
         else
           advanced = state.input.offset
           state.input.rollback
           Failure.new(
-            'Expected any character but got end of input',
+            -> { 'Expected any character but got end of input' },
             advanced,
             state
           )
         end
       end
@@ -62,24 +63,24 @@
 
     # Matches any character in a string
     # Example:
     #  char_in('abc').run('b') # => Success.new('b', 1)
     def char_in(characters_string)
-      characters_array = characters_string.chars
+      characters_set = characters_string.chars
 
       Parser.new do |state|
         state.input.mark_offset
 
         char, bytesize = state.input.peek(1)
 
-        if char && characters_array.include?(char)
+        if char && characters_set.include?(char)
           Success.new(char, bytesize)
         else
           advanced = state.input.offset
           state.input.rollback
           Failure.new(
-            "Expected one of #{characters_array.inspect} but got #{char.inspect}",
+            -> { "Expected one of #{characters_set.to_a.inspect} but got #{char.inspect}" },
             advanced,
             state
           )
         end
       end
@@ -88,49 +89,46 @@
     def char_while(predicate)
       Parser.new do |state|
         state.input.mark_offset
 
         buffer = String.new
-        loop do
-          char, bytesize = state.input.peek(1)
-          break if char.nil? || !predicate.call(char)
+        char, bytesize = state.input.peek(1)
 
+        while char && predicate.call(char)
           buffer << char
           state.input.advance(bytesize)
+          char, bytesize = state.input.peek(1)
         end
 
         if buffer.empty?
           advanced = state.input.offset
           Failure.new(
-            "Predicate never returned true",
+            -> { "Predicate never returned true" },
             advanced,
             state
           )
         else
           Success.new(buffer, 0)
         end
       end
     end
 
-    # Unstable API
     def recursive(&block)
       recursive_parser = nil
 
       placeholder = Parser.new do |state|
         raise "Recursive parser accessed before it was initialized!" if recursive_parser.nil?
 
         recursive_parser.call.run_with_state(state).tap do |result|
           if result.failure?
-            error_msg = "Error in recursive structure around position #{state.input.offset}: #{result.message}"
+            error_msg = -> { "Error in recursive structure around position #{state.input.offset}: #{result.message}" }
             Failure.new(error_msg, state.input.offset, state)
           end
         end
       end
 
       recursive_parser = -> { block.call(placeholder) }
       placeholder
     end
-
-
 
   end
 end