Organize negative conditions

Author: ydah

lib/lrama/context.rb

@@ -255,7 +255,7 @@ def compute_yydefact
 
         # If no default_reduction_rule, default behavior is an
         # error then replace ErrorActionNumber with zero.
-        if !state.default_reduction_rule
+        unless state.default_reduction_rule
           actions.map! do |e|
             if e == ErrorActionNumber
               0
@@ -303,17 +303,17 @@ def compute_yydefgoto
       end
 
       @states.nterms.each do |nterm|
-        if !(states = nterm_to_next_states[nterm])
-          default_goto = 0
-          not_default_gotos = []
-        else
+        if (states = nterm_to_next_states[nterm])
           default_state = states.map(&:last).group_by {|s| s }.max_by {|_, v| v.count }.first
           default_goto = default_state.id
           not_default_gotos = []
           states.each do |from_state, to_state|
             next if to_state.id == default_goto
             not_default_gotos << [from_state.id, to_state.id]
           end
+        else
+          default_goto = 0
+          not_default_gotos = []
         end
 
         k = nterm_number_to_sequence_number(nterm.number)

lib/lrama/counterexamples.rb

@@ -173,7 +173,13 @@ def find_shift_conflict_shortest_state_items(reduce_path, conflict_state, confli
               break
             end
 
-            if !si.item.beginning_of_rule?
+            if si.item.beginning_of_rule?
+              key = [si.state, si.item.lhs]
+              @reverse_productions[key].each do |item|
+                state_item = StateItem.new(si.state, item)
+                queue << (sis + [state_item])
+              end
+            else
               key = [si, si.item.previous_sym]
               @reverse_transitions[key].each do |prev_target_state_item|
                 next if prev_target_state_item.state != prev_state_item.state
@@ -185,12 +191,6 @@ def find_shift_conflict_shortest_state_items(reduce_path, conflict_state, confli
                 queue.clear
                 break
               end
-            else
-              key = [si.state, si.item.lhs]
-              @reverse_productions[key].each do |item|
-                state_item = StateItem.new(si.state, item)
-                queue << (sis + [state_item])
-              end
             end
           end
         else

lib/lrama/grammar/rule_builder.rb

@@ -27,19 +27,15 @@ def initialize(rule_counter, midrule_action_counter, parameterizing_rule_resolve
       end
 
       def add_rhs(rhs)
-        if !@line
-          @line = rhs.line
-        end
+        @line ||= rhs.line
 
         flush_user_code
 
         @rhs << rhs
       end
 
       def user_code=(user_code)
-        if !@line
-          @line = user_code&.line
-        end
+        @line ||= user_code&.line
 
         flush_user_code
 

lib/lrama/lexer.rb

@@ -74,7 +74,7 @@ def location
     end
 
     def lex_token
-      while !@scanner.eos? do
+      until @scanner.eos? do
         case
         when @scanner.scan(/\n/)
           newline
@@ -129,7 +129,7 @@ def lex_c_code
       code = ''
       reset_first_position
 
-      while !@scanner.eos? do
+      until @scanner.eos? do
         case
         when @scanner.scan(/{/)
           code += @scanner.matched
@@ -166,7 +166,7 @@ def lex_c_code
     private
 
     def lex_comment
-      while !@scanner.eos? do
+      until @scanner.eos? do
         case
         when @scanner.scan(/\n/)
           newline

lib/lrama/lexer/token/user_code.rb

@@ -18,7 +18,7 @@ def _references
           scanner = StringScanner.new(s_value)
           references = []
 
-          while !scanner.eos? do
+          until scanner.eos? do
             case
             when reference = scan_reference(scanner)
               references << reference

lib/lrama/option_parser.rb

@@ -18,7 +18,7 @@ def parse(argv)
       @options.report_opts = validate_report(@report)
       @options.grammar_file = argv.shift
 
-      if !@options.grammar_file
+      unless @options.grammar_file
         abort "File should be specified\n"
       end
 

lib/lrama/states.rb

@@ -349,7 +349,7 @@ def compute_includes_relation
               # TODO: need to omit if state == state2 ?
               @includes_relation[key] ||= []
               @includes_relation[key] << [state.id, nterm.token_id]
-              break if !sym.nullable
+              break unless sym.nullable
               i -= 1
             end
           end
@@ -384,7 +384,7 @@ def compute_look_ahead_sets
       @states.each do |state|
         rules.each do |rule|
           ary = @lookback_relation[[state.id, rule.id]]
-          next if !ary
+          next unless ary
 
           ary.each do |state2_id, nterm_token_id|
             # q = state, A -> ω = rule, p = state2, A = nterm
@@ -427,7 +427,7 @@ def compute_shift_reduce_conflicts
             sym = shift.next_sym
 
             next unless reduce.look_ahead
-            next if !reduce.look_ahead.include?(sym)
+            next unless reduce.look_ahead.include?(sym)
 
             # Shift/Reduce conflict
             shift_prec = sym.precedence
@@ -501,7 +501,7 @@ def compute_reduce_reduce_conflicts
 
             intersection = reduce1.look_ahead & reduce2.look_ahead
 
-            if !intersection.empty?
+            unless intersection.empty?
               state.conflicts << State::ReduceReduceConflict.new(symbols: intersection, reduce1: reduce1, reduce2: reduce2)
             end
           end
@@ -513,7 +513,7 @@ def compute_default_reduction
       states.each do |state|
         next if state.reduces.empty?
         # Do not set, if conflict exist
-        next if !state.conflicts.empty?
+        next unless state.conflicts.empty?
         # Do not set, if shift with `error` exists.
         next if state.shifts.map(&:next_sym).include?(@grammar.error_symbol)
 

lib/lrama/states_reporter.rb

@@ -78,7 +78,7 @@ def report_conflicts(io)
           messages << "#{cs[:reduce_reduce].count} reduce/reduce"
         end
 
-        if !messages.empty?
+        unless messages.empty?
           has_conflict = true
           io << "State #{state.id} conflicts: #{messages.join(', ')}\n"
         end
@@ -139,7 +139,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           if lookaheads && item.end_of_rule?
             reduce = state.find_reduce_by_item!(item)
             look_ahead = reduce.selected_look_ahead
-            if !look_ahead.empty?
+            unless look_ahead.empty?
               la = "  [#{look_ahead.map(&:display_name).join(", ")}]"
             end
           end
@@ -159,7 +159,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
         tmp.each do |term, state_id|
           io << "    #{term.display_name.ljust(max_len)}  shift, and go to state #{state_id}\n"
         end
-        io << "\n" if !tmp.empty?
+        io << "\n" unless tmp.empty?
 
         # Report error caused by %nonassoc
         nl = false
@@ -173,7 +173,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           nl = true
           io << "    #{name.ljust(max_len)}  error (nonassociative)\n"
         end
-        io << "\n" if !tmp.empty?
+        io << "\n" unless tmp.empty?
 
         # Report reduces
         nl = false
@@ -222,14 +222,14 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
         tmp.each do |nterm, state_id|
           io << "    #{nterm.id.s_value.ljust(max_len)}  go to state #{state_id}\n"
         end
-        io << "\n" if !tmp.empty?
+        io << "\n" unless tmp.empty?
 
         if solved
           # Report conflict resolutions
           state.resolved_conflicts.each do |resolved|
             io << "    #{resolved.report_message}\n"
           end
-          io << "\n" if !state.resolved_conflicts.empty?
+          io << "\n" unless state.resolved_conflicts.empty?
         end
 
         if counterexamples && state.has_conflicts?
@@ -260,7 +260,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           direct_read_sets = @states.direct_read_sets
           @states.nterms.each do |nterm|
             terms = direct_read_sets[[state.id, nterm.token_id]]
-            next if !terms
+            next unless terms
             next if terms.empty?
 
             str = terms.map {|sym| sym.id.s_value }.join(", ")
@@ -272,7 +272,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           io << "  [Reads Relation]\n"
           @states.nterms.each do |nterm|
             a = @states.reads_relation[[state.id, nterm.token_id]]
-            next if !a
+            next unless a
 
             a.each do |state_id2, nterm_id2|
               n = @states.nterms.find {|n| n.token_id == nterm_id2 }
@@ -286,7 +286,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           read_sets = @states.read_sets
           @states.nterms.each do |nterm|
             terms = read_sets[[state.id, nterm.token_id]]
-            next if !terms
+            next unless terms
             next if terms.empty?
 
             terms.each do |sym|
@@ -299,7 +299,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           io << "  [Includes Relation]\n"
           @states.nterms.each do |nterm|
             a = @states.includes_relation[[state.id, nterm.token_id]]
-            next if !a
+            next unless a
 
             a.each do |state_id2, nterm_id2|
               n = @states.nterms.find {|n| n.token_id == nterm_id2 }
@@ -312,7 +312,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           io << "  [Lookback Relation]\n"
           @states.rules.each do |rule|
             a = @states.lookback_relation[[state.id, rule.id]]
-            next if !a
+            next unless a
 
             a.each do |state_id2, nterm_id2|
               n = @states.nterms.find {|n| n.token_id == nterm_id2 }
@@ -327,7 +327,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           @states.nterms.each do |nterm|
             terms = follow_sets[[state.id, nterm.token_id]]
 
-            next if !terms
+            next unless terms
 
             terms.each do |sym|
               io << "    #{nterm.id.s_value} -> #{sym.id.s_value}\n"
@@ -341,7 +341,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
           max_len = 0
           @states.rules.each do |rule|
             syms = @states.la[[state.id, rule.id]]
-            next if !syms
+            next unless syms
 
             tmp << [rule, syms]
             max_len = ([max_len] + syms.map {|s| s.id.s_value.length }).max
@@ -351,7 +351,7 @@ def report_states(io, itemsets, lookaheads, solved, counterexamples, verbose)
               io << "    #{sym.id.s_value.ljust(max_len)}  reduce using rule #{rule.id} (#{rule.lhs.id.s_value})\n"
             end
           end
-          io << "\n" if !tmp.empty?
+          io << "\n" unless tmp.empty?
         end
 
         # End of Report State

spec/spec_helper.rb

@@ -51,12 +51,12 @@ def initialize(expected)
     def matches?(target)
       @target = target
 
-      if !@expected.is_a?(Lrama::Grammar::Symbol)
+      unless @expected.is_a?(Lrama::Grammar::Symbol)
         @_failure_message = "expected #{@expected.inspect} to be Lrama::Grammar::Symbol"
         return false
       end
 
-      if !@target.is_a?(Lrama::Grammar::Symbol)
+      unless @target.is_a?(Lrama::Grammar::Symbol)
         @_failure_message = "expected #{@target.inspect} to be Lrama::Grammar::Symbol"
         return false
       end
@@ -97,12 +97,12 @@ def initialize(expected)
     def matches?(target)
       @target = target
 
-      if !@expected.is_a?(Array)
+      unless @expected.is_a?(Array)
         @_failure_message = "expected #{@expected.inspect} to be Array"
         return false
       end
 
-      if !@target.is_a?(Array)
+      unless @target.is_a?(Array)
         @_failure_message = "expected #{@target.inspect} to be Array"
         return false
       end