On 15/04/16 4:16 pm, Manuel Gómez wrote:
Although precise, coherent descriptions are available for Haskell 98 and Haskell 2010 for reference in the Reports, the documentation shipped by GHC for many language extensions is often reasonably close in precision and coherence, as far as many students are concerned — and, more importantly, the learning process for a student rarely involves consuming a precise, coherent definition, and often involves a greater degree of experimentation and consumption of explanations aimed to teach, not to serve as reference for language implementors.
I do not aim to suggest that standards are not useful —they surely are—, but standards are of limited use to many students.
I'm reminded of a Prolog textbook that was written with much thought and care, diligently adhering scrupulously to the then-current draft of the ISO Prolog standard, and tested in a Prolog implementation written to conform to it. The book ended up being useless because the standard changed to be somewhat less of a complete break from the past, so eventually there were *no* Prolog systems compatible with the book. Students themselves mostly do not know or care what the standard is. What they *are* affected by is whether their teaching materials agree with the implementation they are using.