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| -rwxr-xr-x | doc/nimrodc.txt | 12 |
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: |