I put this on the haskell wiki at
http://haskell.org/haskellwiki/Poor_Man%27s_Heredoc_in_Haskell
So far I have only linked this from
http://haskell.org/haskellwiki/Simple_unix_tools
I feel like the wiki deserves a section on "Haskell Template
Solutions" distinct from this. However, there is a bit of a namespace
conflict, as "template haskell" is a ghc extension, and so if you
google on it you will get all stuff first.
I wonder if anyone has an opinion on a good title for a wiki page about this.
Haskell String Interpolation?
Haskell String Templates?
But these sound clunky to me.
2007/4/16, Claus Reinke
With regards to the variable interpolation in strings problem, ..
as i mentioned, it is not difficult to hack something up, and in many cases, efficiency doesn't matter much for this part of the problem (though a standard, efficient, well-designed library would be welcome). but if we compare the attached example with here docs in perl or shell or .., we find that we can get rid of all that escaping and concatenation in strings, but:
- the file name should be implicit (the current source) - the dictionary should be implicit (the current variable environment)
the former might be easy to add to the language, and the latter would be a minor subset of template haskell functionality. but they need to be standardized and widely available to be of much use.
claus
ps here's the output:
$ runhaskell Here.hs
this is a poor man's here-document
with quotes ", and escapes \, and line-breaks, and layout without escaping \" \\ \n, without concatenation.
oh, and with some variables, $(too).
<html> <head><title>very important page</title></head> <body> <verb>
this is a poor man's here-document
with quotes ", and escapes \, and line-breaks, and layout without escaping \" \\ \n, without concatenation.
oh, and with some variables, $(too).
</verb> </body> </html>