On Feb 18, 2012, at 2:42 PM, Gary Baumgartner wrote:
>> (filter (lambda (v) (if (and (>= v start) (<= v end)) #t #f))
>> storedlst)
>> )))
> [...]
>
> Consider just (lambda (v) (and (>= v start) (<= v end))) --- no 'if'.
I see a lot of my students doing this -- in whatever language -- because they
think of Booleans as a way to decide which of two things to DO, rather than as
legitimate values in their own right. In fact, the whole world of expressions
is a bit of a foreign country -- a sort of "adjunct" to the more-legitimate
world of statements.
if (blah == true) {
return true;
}
else {
return false;
}
For those of us forced to teach in Java, CheckStyle has two modules,
SimplifyBooleanExpression and SimplifyBooleanReturn, that catch things like
this.
Stephen Bloch
sbl...@adelphi.edu
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