Here's my short manifesto on ">>" and "do" notation. It is based on the precedent set with "negate", a precedent that I also support. ">>" should be a member of the "Monad" class, just as "negate" is a member of the "Num" class! Users should have the power to override the default definition of ">>", just as they have the power to override the default definition of "negate"! Haskell compilers should honor user definitions for ">>" and not hard-wire ">>= \_ ->", just as they should honor user definitions for "negate" and do not hardwire "0 - x"! I have fixed the December 2001 release of Hugs to follow these principles for ">>". (I haven't tested the fix exhaustively. It works on my programs. Corrections appreciated!) Here are the "diffs", before the fix followed by after: connect.h: 74c74 < extern Name nameReturn, nameBind; /* for translating monad comps */ ---
extern Name nameReturn, nameBind, nameSequence; /* for translating monad comps */
type.c: 85c85 < Name nameReturn, nameBind; /* for translating monad comps */ ---
Name nameReturn, nameBind, nameSequence; /* for translating monad comps */ 3267a3268 nameSequence = linkName(">>");
compiler.c: 397c397 < * do { e; qs } => LETREC _h _ = [ e | qs ] in bind m exp _h ---
* do { e; qs } => sequence m e qs 433,442c433,436 < case DOQUAL : { Cell hVar = inventVar(); < Cell ld = cons(pair(singleton(WILDCARD), < transDo(m,e,qs1)), < NIL); < return ap(LETREC, < pair(singleton(pair(hVar,ld)), < ap(ap(ap(nameBind, < m), < translate(snd(q))), < hVar)));
case DOQUAL : { return ap(ap(ap(nameSequence, m), translate(snd(q))), transDo(m,e,qs1));
--- James B. White III (Trey) Center for Computational Sciences Oak Ridge National Laboratory whitejbiii@ornl.gov