Can I assign result of condition?

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Jin X

Joined: 06 Mar 2004
Posts: 133
Location: Russia

Jin X 14 Oct 2019, 12:14

Can I realize something like

Code:

a = (b <> 0)

another way than:

Code:

if b
  a = 1
else
  a = 0
end if

???

More compact.

14 Oct 2019, 12:14

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8356
Location: Kraków, Poland

Tomasz Grysztar 14 Oct 2019, 12:29

No, there is no such thing in fasm's language as assignable result of a condition. Logical expressions can only be used with a command like IF or WHILE. In fasm's semantics "true"/"false" are not really numeric values at all.

14 Oct 2019, 12:29

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20422
Location: In your JS exploiting you and your system

revolution 14 Oct 2019, 15:04

The equals (=) character serves both as an operator and an assignment.

So this code would be ambiguous:

Code:

if a = b ;logical comparison or numeric assignment?

I think if you wanted to allow logical conditions to generate a numeric value then you might want to introduce a separate operator. C uses == for comparison, and = for assignment. And you have probably seen how much confusion that has caused over the years. Especially since C also implicitly evaluates assignments.

14 Oct 2019, 15:04

Tomasz Grysztar

Joined: 16 Jun 2003
Posts: 8356
Location: Kraków, Poland

Tomasz Grysztar 14 Oct 2019, 15:09

revolution wrote:

I think if you wanted to allow logical conditions to generate a numeric value then you might want to introduce a separate operator. C uses == for comparison, and = for assignment. And you have probably seen how much confusion that has caused over the years. Especially since C also implicitly evaluates assignments.

Yes, this might be an underlying justification. The design of fasm's syntax borrows from old languages like Fortran or Basic that had contextual meaning of "=".

14 Oct 2019, 15:09

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20422
Location: In your JS exploiting you and your system

revolution 14 Oct 2019, 15:28

This might work:

Code:

a ← (b <> c)

But typing the ← character is tricky.

Also use a binary operator to coerce logical to numeric conversion:

Code:

if a * (b <> c) > d ;use a binary operator to coerce logical to numeric conversion

14 Oct 2019, 15:28

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