Persistent side effects with Dir, File and FileUtils

src/icr/command_stack.cr

@@ -32,21 +32,27 @@ module Icr
         type = :struct
       when .match /^alias\s/
         type = :alias
+      when .match with_persistent_side_effect
+        type = :side_effect
       when .match /^[A-Z]([A-Za-z0-9_]+)?\s*=[^=~]/
         type = :constant_assignment
       when .match /^macro\s/
         type = :macro
       else
         type = :regular
       end
-      @commands << Command.new(type, command)
+      do_push(Command.new(type, command))
     end
 
     # Pop the last command. It's used in cases if the last command results into error.
     def pop
       @commands.pop
     end
 
+    def printable_execution_result?
+      [:regular, :side_effect].includes?(@commands.last.type)
+    end
+
     # Generate crystal source code, based on the command in the stack.
     def to_code
       code =
@@ -64,6 +70,7 @@ module Icr
 
         def __icr_exec__
         #{code(:regular, 1)}
+        #{code(:side_effect, 1)}
         end
 
         puts "#{DELIMITER}\#{__icr_exec__.inspect}"
@@ -75,5 +82,23 @@ module Icr
       cmds = @commands.select { |cmd| cmd.type == command_type }.map &.value
       cmds.map { |cmd| ("  " * indent_level) + cmd }.join("\n")
     end
+
+    private def do_push(command)
+      pop_when_last_was_side_effect unless @commands.empty?
+      @commands << command
+    end
+
+    # Pop the last command if the last command got side effects.
+    private def pop_when_last_was_side_effect
+      @commands.pop if @commands.last.type == :side_effect
+    end
+
+    private def with_persistent_side_effect
+      # Dir.mkdir(), Dir.mkdir_p(), Dir.rmdir(),
+      # File.delete(), File.link(), File.rename(), File.symlink(),
+      # FileUtils.mkdir(), FileUtils.mkdir_p(), FileUtils.mv(),
+      # FileUtils.rm, FileUtils.rm_r(), FileUtils.rm_rf(), FileUtils.rmdir()
+      /^Dir\.(mkdir|rmdir)|^FileUtils\.(mkdir|mv|rm)|^File\.(delete|link|rename|symlink)/
+    end
   end
 end

src/icr/console.cr

@@ -152,7 +152,7 @@ module Icr
     end
 
     private def print_execution_result?
-      @command_stack.commands.last.type == :regular
+      @command_stack.printable_execution_result?
     end
 
     private def __exit__