jhass · March 30, 2017 07:29 · Mar 30, 2017 · Mar 29, 2017 · Mar 29, 2017 · Mar 29, 2017
diff --git a/injecting_io.cr b/injecting_io.cr
@@ -53,7 +53,7 @@ class InjectingIO
 
     first_half = slice
     second_half = nil
-    0.upto(slice.size - 1) do |i|
+    slice.each_index do |i|
       candidate = slice[i, @token.size]?
       if candidate == @token
         first_half = slice[0, i]?

diff --git a/injecting_io.cr b/injecting_io.cr
@@ -19,7 +19,6 @@ class InjectingIO
   @remaining_token : Bytes?
 
   def initialize(@io : IO, @token : Bytes, @replacement : Bytes)
-    STDERR.puts "Token: #{@token}"
   end
 
   def read(slice : Bytes)

diff --git a/injecting_io.cr b/injecting_io.cr
@@ -43,9 +43,11 @@ class InjectingIO
           @remaining_token = remaining_token[slice.size, -1]?
           return
         else
+          @io.write(@token[0, @token.size - remaining_token.size])
           @remaining_token = nil
         end
       else
+        @io.write(@token[0, @token.size - remaining_token.size])
         @remaining_token = nil
       end
     end
@@ -92,4 +94,6 @@ io.print "o"
 io.puts "o is the coolest"
 io.print "foo"
 io.puts " is okay too"
+io.print "fo"
+io.puts " stays"
 io.close
diff --git a/injecting_io.cr b/injecting_io.cr
@@ -0,0 +1,95 @@
+struct Slice(T)
+  def []?(start, count)
+    if start + count >= size
+      count = -1
+    end
+
+    if count < 0
+      count = size - start + (count + 1)
+    end
+
+    self[start, count]
+  end
+end
+
+class InjectingIO
+  include IO
+
+  getter? closed = false
+  @remaining_token : Bytes?
+
+  def initialize(@io : IO, @token : Bytes, @replacement : Bytes)
+    STDERR.puts "Token: #{@token}"
+  end
+
+  def read(slice : Bytes)
+    check_open
+
+    @io.read(slice)
+  end
+
+  def write(slice : Bytes)
+    check_open
+
+    remaining_token = @remaining_token
+    if remaining_token
+      if slice[0, remaining_token.size]? == remaining_token
+        @io.write(@replacement)
+        @io.write(slice[remaining_token.size, -1]?)
+        @remaining_token = nil
+        return
+      elsif slice.size < remaining_token.size
+        if slice == remaining_token[0, slice.size]?
+          @remaining_token = remaining_token[slice.size, -1]?
+          return
+        else
+          @remaining_token = nil
+        end
+      else
+        @remaining_token = nil
+      end
+    end
+
+    first_half = slice
+    second_half = nil
+    0.upto(slice.size - 1) do |i|
+      candidate = slice[i, @token.size]?
+      if candidate == @token
+        first_half = slice[0, i]?
+        second_half = slice[i + @token.size, -1]?
+        break
+      elsif candidate.size < @token.size && candidate == @token[0, candidate.size]?
+        @remaining_token = @token[candidate.size, -1]?
+        first_half = slice[0, i]?
+        break
+      end
+    end
+
+    @io.write(first_half)
+
+    if second_half
+      @io.write(@replacement)
+      @io.write(second_half)
+    end
+  end
+
+  def close
+    @io.close
+    @closed = true
+  end
+end
+
+io = InjectingIO.new(STDOUT, "foo".to_slice, "bar".to_slice)
+
+io.puts "Hello World"
+io.puts "Hello foo"
+io.print "fo"
+io.puts "o is cool"
+io.print "f"
+io.puts "oo is cooler"
+io.print "f"
+io.print "o"
+io.puts "o is the coolest"
+io.print "foo"
+io.puts " is okay too"
+io.close