Hello,

I've just posted another article, but thought I should separate these for clarity.

First of all, similar questions have already been asked in my article as well as this article by anon.

That is: If a function has been initialised with no return, if called in an expression is it invalid, or can we safely equate it to zero. Do all functions have a decimal return type with a default of zero, or are there also void functions?

Second of all, ML seems to be relatively strict about scope (see part 12 of "Our ml Language"):

"a function's parameters and any other identifiers used in a function body are local to that function, and become unavailable when the function's execution completes"

So, can a function modify variables defined above its scope? As in, in the ML code:

a <- 3

function dosomething
	a <- a + 2

print a

Will the output be 3, or 5? Can function dosomething modify the variable defined before it, or only use it as in sample 8?

Thank you.

"Harrison Lisle" [email protected] wrote:

Hello,

I've just posted another article, but thought I should separate these for clarity.

First of all, similar questions have already been asked in my article as well as this article by anon.

That is: If a function has been initialised with no return, if called in an expression is it invalid, or can we safely equate it to zero. Do all functions have a decimal return type with a default of zero, or are there also void functions?

Second of all, ML seems to be relatively strict about scope (see part 12 of "Our ml Language"):

"a function's parameters and any other identifiers used in a function body are local to that function, and become unavailable when the function's execution completes"

So, can a function modify variables defined above its scope? As in, in the ML code:

a <- 3

function dosomething
	a <- a + 2

print a

Will the output be 3, or 5? Can function dosomething modify the variable defined before it, or only use it as in sample 8?

Thank you.

I believe it is fine to return zero if a function doesn't have a return value.

Amitava please respond to the second question.