In computer science, a function type (also arrow type or exponential) is the type of a variable or parameter to which a function has or can be assigned or the result type of a higher-order function returning a function.
A function type depends on the type of the parameters and the result type of the function (it, or more accurately the unapplied type constructor · → ·, is a higher-kinded type). In theoretical settings and languages where functions are defined in curried form, such as the simply typed lambda calculus, a function type depends on exactly two types, the domain A and the range B. Here a function type is often denoted A → B, following mathematical convention, or BA, based on the fact that there exist exactly BA (exponentially many) set-theoretic functions mapping A to B.
Read more about Function Type: Programming Languages, Denotational Semantics
Famous quotes containing the words function and/or type:
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—Frank Smith (b. 1928)
“It used to be said that you had to know what was happening in America because it gave us a glimpse of our future. Today, the rest of America, and after that Europe, had better heed what happens in California, for it already reveals the type of civilisation that is in store for all of us.”
—Alistair Cooke (b. 1908)