It is true though that whenever you overload an operator you depend on the programmer understanding more about a single operation. Thus by definition overloading increases the complexity of a language.
There is some significant complexity in setting a variable. Note the current existence of four (or more) different forms of 'fn: 'fn (anonymous), 'afn (capturing 'self as a local name), 'rfn (using a user defined local name), and 'def (using a user defined global name). All these forms exist for the purpose of creating functions, but they each has a different way of setting varaibles.
How do you capture that complexity if you want to start combining them into a single operation? Do you just ignore everything except 'fn and 'def and say the user can type the extra character for 'afn and 'rfn? That seems rather inconsistent.
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> It is true though that whenever you overload an operator you depend on the programmer understanding more about a single operation. Thus by definition overloading increases the complexity of a language.
that's if we're looking at it from the perspective of the operator. but if we look at it from the perspective of an expression, i think it is simpler. to illustrate: one of the nice examples on the front page of ruby-lang.org is the following (keeping their comments):
# Ruby knows what you
# mean, even if you
# want to do math on
# an entire Array
cities = %w[ London
Oslo
Paris
Amsterdam
Berlin ]
visited = %w[Berlin Oslo]
puts "I still need " +
"to visit the " +
"following cities:",
cities - visited
if we look at it from the perspective of the operators, we see we've overloaded + and - for non-numeric types. however, if we look at it from the perspective of the programmer as they are writing those lines, we see that the programmer just wants to say "remove the cities i've visited from the cities i have to visit," and "cities - visited" is almost a direct translation of that. it makes sense. the fact that that operator happens to be overloaded from another domain is irrelevant. the context secures the role of the operator