The same is true for python. I spent some time trying to write a CSV parser in guile scheme that was as fast as python's (mistakenly believing that python's CSV

The same is true for python. I spent some time trying to write a CSV parser in guile scheme that was as fast as python's (mistakenly believing that python's CSV parser was actually written in python). I wrote a fast-ish streaming FSM-parser (about 100loc) but only managed to be about 1.7x as fast as python's CSV module. Browsing the python source I realised that the python parser was written in optimised and nicely buffered C. I could probably compete with python if I used guile's lower level C-procedures, but I sort of lost interest after that :)