When the compiler handles this, it is usually called "automatic deforestation". One technique for this (that Haskell's compiler implements) is "stream fusion".

When the compiler handles this, it is usually called "automatic deforestation". One technique for this (that Haskell's compiler implements) is "stream fusion". A brief overview of stream fusion is given at https://stackoverflow.com/questions/578063/what-is-haskells-stream-fusion https://stackoverflow.com/questions/578063/what-is-haskells-... and a lengthier paper is at http://fun.cs.tufts.edu/stream-fusion.pdf http://fun.cs.tufts.edu/stream-fusion.pdf.