On Thursday 03 June 2010 16:03:11, Kevin Jardine wrote:
(I've done a basic Google search on this with no results. Apologies if this has been asked before.)
I am coding a web application in which the content is a Unicode string built up over multiple functions and maintained in a State structure.
I gather that the String module is inefficient and that Data.Text would be a better choice.
Is it more efficient to build up a list of Text objects over time and combine them together with a single Data.Text.concat for the final output or to run Data.Text.append for each new string so that I am maintaining a single Text object rather than a list?
As Data.Text.append requires copying both strings each time, my gut feeling is that concat would be much more efficient, but Haskell has surprised me before, so I wanted to check.
Kevin
I'd say, use Data.Text.Lazy and its 'fromChunks' function if you produce the string chunkwise. That avoids copying. Perhaps Data.ByteString[.Lazy].UTF8 is an even better choice than Data.Text (depends on what you do).