Matching elements of records
Fri Oct 29 08:37:48 CEST 2004
From: "Richard A. O'Keefe" <>
> To me it is simply inconsistent to bind X in the body of a function
> by writing
> X = [Y|Ys]
> and then to turn around and do the exact OPPOSITE in the head of
> a function by writing
> [Y|Ys] = X
Without trying to pretend I know more than you, Richard, there is one thing that
I'd like to point out (which might or might not invalidate your point).
As I see it, the alternatives are these:
a) f(X = [Y|Ys]) -> ...
b) f([Y|Ys] = X) -> ...
c) f(X) ->
[Y|Ys] = X, ...
d) f([Y|Ys]) ->
X = [Y|Ys], ...
Alternatives a and d are consistent with each other, and in line with your
Alternatives b and c are consistent with each other, and in line with Robert's
However, alternative d seems a little strange and there's something unnatural
about it. The match follows the "heavy constituent comes later" rule, but the
function as a whole doesn't (argument name should have come first). And I think
when it comes to readability, the function as a whole is more important to
follow the rule.
That said, I too would like to have a separate operator for record field
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