From a82e3abc907ba4284c0e13f6668a2d37eba31a49 Mon Sep 17 00:00:00 2001
From: crabonature <crabo.nature@gmail.com>
Date: Sat, 10 Feb 2018 12:42:31 +0100
Subject: [PATCH 1/2] Persistent side effects with Dir

---
 src/icr/command_stack.cr | 23 ++++++++++++++++++++++-
 src/icr/console.cr       |  2 +-
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/icr/command_stack.cr b/src/icr/command_stack.cr
index c5a1dba..df127e7 100644
--- a/src/icr/command_stack.cr
+++ b/src/icr/command_stack.cr
@@ -32,6 +32,8 @@ 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/
@@ -39,7 +41,7 @@ module Icr
       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.
@@ -47,6 +49,10 @@ module Icr
       @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 +82,19 @@ 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\.rmdir|^Dir\.mkdir_p|^Dir\.mkdir/
+    end
   end
 end
diff --git a/src/icr/console.cr b/src/icr/console.cr
index 6d457f5..9821a3c 100644
--- a/src/icr/console.cr
+++ b/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__

From 012bbd6c48b23b5986e79155fb1a69e252255611 Mon Sep 17 00:00:00 2001
From: crabonature <crabo.nature@gmail.com>
Date: Sun, 11 Feb 2018 13:39:41 +0100
Subject: [PATCH 2/2] Persistent side effects with File and FileUtils

---
 src/icr/command_stack.cr | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/icr/command_stack.cr b/src/icr/command_stack.cr
index df127e7..e2e2fe2 100644
--- a/src/icr/command_stack.cr
+++ b/src/icr/command_stack.cr
@@ -94,7 +94,11 @@ module Icr
     end
 
     private def with_persistent_side_effect
-      /^Dir\.rmdir|^Dir\.mkdir_p|^Dir\.mkdir/
+      # 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