Modernize parser and shell code with Ruby 4 features

ruby/shell/builtins.rb

@@ -60,9 +60,10 @@ module Shell
     def builtin_cd(args)
       dir = args.first
       oldpwd = Dir.pwd
-      target = if dir.nil?
+      target = case dir
+      in nil
         Dir.home
-      elsif dir == "-"
+      in "-"
         ENV["OLDPWD"] || oldpwd
       else
         dir
@@ -85,7 +86,7 @@ module Shell
         logger.warn "#{red("[ERROR]")} Invalid export command"
         return -1
       else
-        ENV[name] = value_parts.join("=").gsub(EXPORT_VARIABLE_PATTERN) { |m| ENV[m[1..]] || "" }
+        ENV[name] = value_parts.join("=").gsub(EXPORT_VARIABLE_PATTERN) { ENV[it[1..]] || "" }
       end
       0
     end

ruby/shell/repl.rb

@@ -54,19 +54,24 @@ module Shell
       commands = parse_line(line)
       result = 0
       commands.each do |entry|
-        command = entry[:command]
-        next if command.strip.empty?
-        next if entry[:op] == :and && result != 0
+        case entry
+        in StringParser::Command[text:, op:]
+          command = text
+          next if command.strip.empty?
+          next if op == :and && result != 0
 
-        args = word_expander.expand(command)
-        program = args.shift
-        logger.verbose "Parsed command: #{program} #{args.inspect}"
-        if builtins.builtin?(program)
-          logger.verbose "Executing builtin #{program}"
-          result = builtins.exec(program, args)
+          args = word_expander.expand(command)
+          program = args.shift
+          logger.verbose "Parsed command: #{program} #{args.inspect}"
+          if builtins.builtin?(program)
+            logger.verbose "Executing builtin #{program}"
+            result = builtins.exec(program, args)
+          else
+            logger.verbose "Shelling out for #{program}"
+            result = job_control.exec_command(program, args)
+          end
         else
-          logger.verbose "Shelling out for #{program}"
-          result = job_control.exec_command(program, args)
+          raise ArgumentError, "Unknown parsed command node: #{entry.inspect}"
         end
       end
       result
@@ -76,12 +81,8 @@ module Shell
     end
 
     # Looks like this: /path/to/somewhere%
-    def prompt(pwd)
-      "#{blue(pwd)}#{white("%")} #{CLEAR}"
-    end
+    def prompt(pwd) = "#{blue(pwd)}#{white("%")} #{CLEAR}"
 
-    def parse_line(line)
-      StringParser.split_commands(line)
-    end
+    def parse_line(line) = StringParser.split_commands(line)
   end
 end

ruby/shell/string_parser.rb

@@ -1,5 +1,6 @@
 module Shell
   class StringParser
+    Command = Data.define(:text, :op)
     Token = Data.define(:type, :value)
 
     class Scanner
@@ -336,22 +337,20 @@ module Shell
         tokens = Scanner.new(line).tokenize_command_list
 
         tokens.each do |token|
-          case token.type
-          when :text
-            commands << {command: token.value, op: next_op}
-            if next_op == :and && token.value.strip.empty?
+          case token
+          in Token[type: :text, value:]
+            if next_op == :and && value.strip.empty?
               raise ArgumentError, "syntax error: expected command after `&&`"
             end
+            commands << Command.new(text: value, op: next_op)
             next_op = :always
-          when :separator
-            if token.value == :and
-              if commands.empty? || commands.last[:command].strip.empty?
-                raise ArgumentError, "syntax error near unexpected token `&&`"
-              end
-              next_op = :and
-            else
-              next_op = :always
+          in Token[type: :separator, value: :and]
+            if commands.empty? || commands.last.text.strip.empty?
+              raise ArgumentError, "syntax error near unexpected token `&&`"
             end
+            next_op = :and
+          in Token[type: :separator, value: :always]
+            next_op = :always
           else
             raise ArgumentError, "Unknown token type: #{token.type}"
           end
@@ -360,9 +359,7 @@ module Shell
         commands
       end
 
-      def read_dollar_paren(line, start_index)
-        Scanner.new(line, index: start_index).read_dollar_paren_body
-      end
+      def read_dollar_paren(line, start_index) = Scanner.new(line, index: start_index).read_dollar_paren_body
     end
   end
 end

ruby/shell/word_expander.rb

@@ -39,7 +39,7 @@ module Shell
           expanded = expand_variables(word.text)
             .tr(ESCAPED_DOLLAR, "$")
             .tr(ESCAPED_BACKTICK, "`")
-          expand_braces(expanded).map { |part| SplitWord.new(text: part, globbed: word.globbed) }
+          expand_braces(expanded).map { SplitWord.new(text: it, globbed: word.globbed) }
         end
         .flat_map do |word|
           if word.globbed
@@ -116,7 +116,7 @@ module Shell
             if glob_words.empty?
               words << SplitWord.new(text: field, globbed: false)
             else
-              glob_words.each { |glob_word| words << SplitWord.new(text: glob_word, globbed: true) }
+              glob_words.each { words << SplitWord.new(text: it, globbed: true) }
             end
           else
             words << SplitWord.new(text: field, globbed: false)
@@ -535,7 +535,7 @@ module Shell
       return [word] unless body.include?(",")
 
       parts = body.split(",", -1)
-      parts.flat_map { |part| expand_braces(prefix + part + suffix) }
+      parts.flat_map { expand_braces(prefix + it + suffix) }
     end
 
     def escaped_replacement(char)