Consider the following definition fun f(a, b, c) = a + (if b > c then b else c) + 1 using Hindley-Milner type inference, determine the type of f. Note that the if expression evaluates to a value (either b or c) which gets added to a and 1.
Solution
We will split language into elements...
a ---> identifier
+ ---> operator
if ---> condition
b ---> identifier
> ---> relational operator
c ---> identifier
then b else c ---> compute condition primitive application
1 ---> Integer
So from above all steps our conclusion is..
a may be either integer or double.. so by looking into identifer a, we cannot judge.
From second expression, if condition the result may be \"b\" or \"c\". We don\'t know exact \"b\" and \"c\" variables.
So we cannot judge.
But finally we are adding 1 to result which results integer result. Since we cannot add integer to String.
So type of f is int.
.
Consider the following definition fun f(a- b- c) - a + (if b - c then.docx
1. Consider the following definition fun f(a, b, c) = a + (if b > c then b else c) + 1 using Hindley-
Milner type inference, determine the type of f. Note that the if expression evaluates to a value
(either b or c) which gets added to a and 1.
Solution
We will split language into elements...
a ---> identifier
+ ---> operator
if ---> condition
b ---> identifier
> ---> relational operator
c ---> identifier
then b else c ---> compute condition primitive application
1 ---> Integer
So from above all steps our conclusion is..
a may be either integer or double.. so by looking into identifer a, we cannot judge.
From second expression, if condition the result may be "b" or "c". We don't know exact "b"
and "c" variables.
So we cannot judge.
But finally we are adding 1 to result which results integer result. Since we cannot add integer to
String.
So type of f is int.
