map/filter/reduce/lambda opinions and background unscientificmini-survey

Terry Reedy tjreedy at
Wed Jul 6 03:58:58 CEST 2005

"Steven Bethard" <steven.bethard at> wrote in message 
news:-8ydnZxXGOCQvlbfRVn-3Q at
> OTOH, I fully agree with Peter Hansen: "Really, the name is such a
> trivial, unimportant part of this whole thing that it's hardly worth
> discussing."

>From a certain viewpoint, I would agree.  Yet, the word 'lambda' *is* the 
center of most of the fuss.  For beginners, it is a minor issue: learn it 
and move on.  But for some functionalists, it is a major issue.  They 
'know' that lambda means 'expressionized anonymous function'.  And in 
lambda calculus, it is the main actor.  But in Python, lambda only means 
anonymous trivial function.  It is only an expressionized convenience 
abbreviation for an important but small subset of possible functions.  So 
for years, such knowledgeable people have called for and proposed various 
syntaxes for 'proper lambdas' or 'true lambdas', saying pretty clearly that 
what Python has is improper or false.  Would there have been so much fuss 
if the keyword had been 'fun' and the word 'lambda' had never appeared in 
the Python docs?  I strongly doubt it.

I also suspect that the years of fuss over Python's lambda being what it is 
rather that what it is 'supposed' to be (and is in other languages) but is 
not, has encourage Guido to consider just getting rid of it.  I personally 
might prefer keeping the feature but using a different keyword.

Terry J. Reedy

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