Improve output when executing the help command

exe/lrama

@@ -3,4 +3,4 @@
 $LOAD_PATH << File.join(__dir__, "../lib")
 require "lrama"
 
-Lrama::Command.new(ARGV.dup).run
+Lrama::Command.new.run(ARGV.dup)

lib/lrama.rb

@@ -5,6 +5,8 @@
 require "lrama/digraph"
 require "lrama/grammar"
 require "lrama/lexer"
+require "lrama/option_parser"
+require "lrama/options"
 require "lrama/output"
 require "lrama/parser"
 require "lrama/report"

lib/lrama/command.rb

@@ -1,162 +1,40 @@
-require 'optparse'
-
 module Lrama
   class Command
-    def initialize(argv)
-      @argv = argv
-
-      @skeleton = "bison/yacc.c"
-      @header = false
-      @header_file = nil
-      @report = []
-      @report_file = nil
-      @outfile = "y.tab.c"
-      @trace = []
-      @error_recovery = false
-      @grammar_file = nil
-      @report_file = nil
-      @trace_opts = nil
-      @report_opts = nil
-    end
+    def run(argv)
+      options = OptionParser.new.parse(argv)
 
-    def run
-      parse_option
-
-      Report::Duration.enable if @trace_opts[:time]
+      Report::Duration.enable if options.trace_opts[:time]
 
       warning = Lrama::Warning.new
-      grammar = Lrama::Parser.new(@y.read).parse
-      @y.close if @y != STDIN
-      states = Lrama::States.new(grammar, warning, trace_state: (@trace_opts[:automaton] || @trace_opts[:closure]))
+      grammar = Lrama::Parser.new(options.y.read).parse
+      options.y.close if options.y != STDIN
+      states = Lrama::States.new(grammar, warning, trace_state: (options.trace_opts[:automaton] || options.trace_opts[:closure]))
       states.compute
       context = Lrama::Context.new(states)
 
-      if @report_file
+      if options.report_file
         reporter = Lrama::StatesReporter.new(states)
-        File.open(@report_file, "w+") do |f|
-          reporter.report(f, **@report_opts)
+        File.open(options.report_file, "w+") do |f|
+          reporter.report(f, **options.report_opts)
         end
       end
 
-      File.open(@outfile, "w+") do |f|
+      File.open(options.outfile, "w+") do |f|
         Lrama::Output.new(
           out: f,
-          output_file_path: @outfile,
-          template_name: @skeleton,
-          grammar_file_path: @grammar_file,
-          header_file_path: @header_file,
+          output_file_path: options.outfile,
+          template_name: options.skeleton,
+          grammar_file_path: options.grammar_file,
+          header_file_path: options.header_file,
           context: context,
           grammar: grammar,
-          error_recovery: @error_recovery,
+          error_recovery: options.error_recovery,
         ).render
       end
 
       if warning.has_error?
         exit 1
       end
     end
-
-    private
-
-    def validate_report(report)
-      bison_list = %w[states itemsets lookaheads solved counterexamples cex all none]
-      others = %w[verbose]
-      list = bison_list + others
-      not_supported = %w[cex none]
-      h = { grammar: true }
-
-      report.each do |r|
-        if list.include?(r) && !not_supported.include?(r)
-          h[r.to_sym] = true
-        else
-          raise "Invalid report option \"#{r}\"."
-        end
-      end
-
-      if h[:all]
-        (bison_list - not_supported).each do |r|
-          h[r.to_sym] = true
-        end
-
-        h.delete(:all)
-      end
-
-      return h
-    end
-
-    def validate_trace(trace)
-      list = %w[
-        none locations scan parse automaton bitsets
-        closure grammar resource sets muscles tools
-        m4-early m4 skeleton time ielr cex all
-      ]
-      h = {}
-
-      trace.each do |t|
-        if list.include?(t)
-          h[t.to_sym] = true
-        else
-          raise "Invalid trace option \"#{t}\"."
-        end
-      end
-
-      return h
-    end
-
-    def parse_option
-      opt = OptionParser.new
-
-      # opt.on('-h') {|v| p v }
-      opt.on('-V', '--version') {|v| puts "lrama #{Lrama::VERSION}"; exit 0 }
-
-      # Tuning the Parser
-      opt.on('-S', '--skeleton=FILE') {|v| @skeleton = v }
-      opt.on('-t') {  } # Do nothing
-
-      # Output Files:
-      opt.on('-h', '--header=[FILE]') {|v| @header = true; @header_file = v }
-      opt.on('-d') { @header = true }
-      opt.on('-r', '--report=THINGS', Array) {|v| @report = v }
-      opt.on('--report-file=FILE')    {|v| @report_file = v }
-      opt.on('-v') {  } # Do nothing
-      opt.on('-o', '--output=FILE')   {|v| @outfile = v }
-
-      # Hidden
-      opt.on('--trace=THINGS', Array) {|v| @trace = v }
-
-      # Error Recovery
-      opt.on('-e') {|v| @error_recovery = true }
-
-      opt.parse!(@argv)
-
-      @trace_opts = validate_trace(@trace)
-      @report_opts = validate_report(@report)
-
-      @grammar_file = @argv.shift
-
-      if !@grammar_file
-        abort "File should be specified\n"
-      end
-
-      if @grammar_file == '-'
-        @grammar_file = @argv.shift or abort "File name for STDIN should be specified\n"
-        @y = STDIN
-      else
-        @y = File.open(@grammar_file, 'r')
-      end
-
-      if [email protected]? && @report_file.nil? && @grammar_file
-        @report_file = File.dirname(@grammar_file) + "/" + File.basename(@grammar_file, ".*") + ".output"
-      end
-
-      if !@header_file && @header
-        case
-        when @outfile
-          @header_file = File.dirname(@outfile) + "/" + File.basename(@outfile, ".*") + ".h"
-        when @grammar_file
-          @header_file = File.dirname(@grammar_file) + "/" + File.basename(@grammar_file, ".*") + ".h"
-        end
-      end
-    end
   end
 end

lib/lrama/option_parser.rb

@@ -0,0 +1,124 @@
+require 'optparse'
+
+module Lrama
+  # Handle option parsing for the command line interface.
+  class OptionParser
+    def initialize
+      @options = Options.new
+      @trace = []
+      @report = []
+    end
+
+    def parse(argv)
+      parse_by_option_parser(argv)
+
+      @options.trace_opts = validate_trace(@trace)
+      @options.report_opts = validate_report(@report)
+      @options.grammar_file = argv.shift
+
+      if [email protected]_file
+        abort "File should be specified\n"
+      end
+
+      if @options.grammar_file == '-'
+        @options.grammar_file = argv.shift or abort "File name for STDIN should be specified\n"
+      else
+        @options.y = File.open(@options.grammar_file, 'r')
+      end
+
+      if [email protected]? && @options.report_file.nil? && @options.grammar_file
+        @options.report_file = File.dirname(@options.grammar_file) + "/" + File.basename(@options.grammar_file, ".*") + ".output"
+      end
+
+      if [email protected]_file && @options.header
+        case
+        when @options.outfile
+          @options.header_file = File.dirname(@options.outfile) + "/" + File.basename(@options.outfile, ".*") + ".h"
+        when @options.grammar_file
+          @options.header_file = File.dirname(@options.grammar_file) + "/" + File.basename(@options.grammar_file, ".*") + ".h"
+        end
+      end
+
+      @options
+    end
+
+    private
+
+    def parse_by_option_parser(argv)
+      ::OptionParser.new do |o|
+        o.banner = <<~BANNER
+          Lrama is LALR (1) parser generator written by Ruby.
+
+          Usage: lrama [options] FILE
+        BANNER
+        o.separator ''
+        o.separator 'Tuning the Parser:'
+        o.on('-S', '--skeleton=FILE', 'specify the skeleton to use') {|v| @options.skeleton = v }
+        o.on('-t', 'reserved, do nothing') { }
+        o.separator ''
+        o.separator 'Output:'
+        o.on('-h', '--header=[FILE]', 'also produce a header file named FILE') {|v| @options.header = true; @options.header_file = v }
+        o.on('-d', 'also produce a header file') { @options.header = true }
+        o.on('-r', '--report=THINGS', Array, 'also produce details on the automaton') {|v| @report = v }
+        o.on('--report-file=FILE', 'also produce details on the automaton output to a file named FILE') {|v| @options.report_file = v }
+        o.on('-o', '--output=FILE', 'leave output to FILE') {|v| @options.outfile = v }
+        o.on('--trace=THINGS', Array, 'also output trace logs at runtime') {|v| @trace = v }
+        o.on('-v', 'reserved, do nothing') { }
+        o.separator ''
+        o.separator 'Error Recovery:'
+        o.on('-e', 'enable error recovery') {|v| @options.error_recovery = true }
+        o.separator ''
+        o.separator 'Other options:'
+        o.on('-V', '--version', "output version information and exit") {|v| puts "lrama #{Lrama::VERSION}"; exit 0 }
+        o.on('--help', "display this help and exit") {|v| puts o; exit 0 }
+        o.separator ''
+        o.parse!(argv)
+      end
+    end
+
+    def validate_report(report)
+      bison_list = %w[states itemsets lookaheads solved counterexamples cex all none]
+      others = %w[verbose]
+      list = bison_list + others
+      not_supported = %w[cex none]
+      h = { grammar: true }
+
+      report.each do |r|
+        if list.include?(r) && !not_supported.include?(r)
+          h[r.to_sym] = true
+        else
+          raise "Invalid report option \"#{r}\"."
+        end
+      end
+
+      if h[:all]
+        (bison_list - not_supported).each do |r|
+          h[r.to_sym] = true
+        end
+
+        h.delete(:all)
+      end
+
+      return h
+    end
+
+    def validate_trace(trace)
+      list = %w[
+        none locations scan parse automaton bitsets
+        closure grammar resource sets muscles tools
+        m4-early m4 skeleton time ielr cex all
+      ]
+      h = {}
+
+      trace.each do |t|
+        if list.include?(t)
+          h[t.to_sym] = true
+        else
+          raise "Invalid trace option \"#{t}\"."
+        end
+      end
+
+      return h
+    end
+  end
+end

lib/lrama/options.rb

@@ -0,0 +1,23 @@
+module Lrama
+  # Command line options.
+  class Options
+    attr_accessor :skeleton, :header, :header_file,
+                  :report_file, :outfile,
+                  :error_recovery, :grammar_file,
+                  :report_file, :trace_opts, :report_opts, :y
+
+    def initialize
+      @skeleton = "bison/yacc.c"
+      @header = false
+      @header_file = nil
+      @report_file = nil
+      @outfile = "y.tab.c"
+      @error_recovery = false
+      @grammar_file = nil
+      @report_file = nil
+      @trace_opts = nil
+      @report_opts = nil
+      @y = STDIN
+    end
+  end
+end