Call a function: Difference between revisions
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end
</syntaxhighlight>
=={{header|EMal}}==
<syntaxhighlight lang="emal">
# an utility function to better solve the task
fun task = void by text about, fun code
writeLine(0U00b7 + " " + about)
code()
end
fun answer = void by var message do writeLine(" " + message) end
# few definitions
fun noArgumentsFunction = int by block do return 97 end
fun fixedArgumentsFunction = void by var a, var b do end
fun variadicFunction = void by text a, some var values do end
fun funArgumentFunction = var by fun f, var b do return f() + b end
task("Calling a function that requires no arguments", void by block
answer("Is supported.")
noArgumentsFunction()
end)
task("Calling a function with a fixed number of arguments", void by block
answer("Is supported.")
fixedArgumentsFunction(97, 3.14)
end)
task("Calling a function with optional arguments", void by block
answer("Not supported in EMal.")
end)
task("Calling a function with a variable number of arguments", void by block
answer("Variadic functions are supported.")
variadicFunction("mandatory", 97, 3.14)
variadicFunction("mandatory", 97)
end)
task("Calling a function with named arguments", void by block
answer("Not supported in EMal.")
end)
task("Using a function in statement context", void by block
answer("Is supported.")
if true do noArgumentsFunction()
else do fixedArgumentsFunction(97, 3.14) end
end)
task("Using a function in first-class context within an expression", void by block
answer("Functions are first class, can be passed as arguments and returned.")
answer(funArgumentFunction(noArgumentsFunction, 3.14))
end)
task("Obtaining the return value of a function", void by block
answer("Is supported.")
int value = noArgumentsFunction()
answer(value)
end)
task("Distinguishing built-in functions and user-defined functions", void by block
answer("No distinction.")
end)
task("Distinguishing subroutines and functions", void by block
answer("No distinction, we support void return type.")
end)
task("Stating whether arguments are passed by value or by reference", void by block
answer("Pass by value, but text, blob, objects hold a reference.")
end)
task("Is partial application possible and how", void by block
answer("Is supported.")
^|I had some confusion about partial application and currying, thanks to these links:
| https://stackoverflow.com/questions/218025/what-is-the-difference-between-currying-and-partial-application
| https://web.archive.org/web/20161023205431/http://www.uncarved.com/articles/not_curryin
|^
# Partial applying
fun add = int by int a, int b do return a + b end
fun partial = fun by fun f, int a
return int by int b
return add(a, b)
end
end
fun add7 = partial(add, 7)
answer(add(7, 5))
answer(add7(5))
# Currying
fun addN = fun by int n
return int by int x
return x + n
end
end
fun plus = int by int a, int b
fun addA = addN(a)
return addA(b)
end
answer(plus(7, 5))
end)
</syntaxhighlight>
{{out}}
<pre>
</pre>
=={{header|Erlang}}==
<syntaxhighlight lang="erlang">
| |||