system.shallow documented

1 files changed, 12 insertions, 0 deletions

diff --git a/doc/nimrodc.txt b/doc/nimrodc.txt
index 58cfa22f6..77a96ee74 100755
--- a/doc/nimrodc.txt
+++ b/doc/nimrodc.txt
@@ -419,6 +419,18 @@ For ``let`` symbols a copy is not always necessary:
   let s = varA    # may only copy a pointer if it safe to do so

 

 

+If you know what you're doing, you can also mark single string (or sequence)

+objects as `shallow`:idx:\:

+

+.. code-block:: Nimrod

+  var s = "abc"

+  shallow(s) # mark 's' as shallow string

+  var x = s  # now might does not copy the string!

+  

+Usage of ``shallow`` is always safe once you know the string won't be modified

+anymore, similar to Ruby's `freeze`:idx:.

+

+

 The compiler optimizes string case statements: A hashing scheme is used for them

 if several different string constants are used. So code like this is reasonably

 efficient: