| Pliant talk forum
Discussion: Constants
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| Message posted by maybe Marcus on 2002/05/02 21:01:27 |
I have noticed that constant definitions are not mentioned in the documentation.
The syntax seems to be:
constant 'identifier' 'expression'
where expression is:
- a number, a string, or a previously defined identifier, or
- expression 'operator' expression, where 'operator' is any Pliant operator, or
- a call to a function or method
Am I missing something?
Could someone precise its semantics? |
| Message posted by maybe Hubert Tonneau on 2002/05/02 21:13:45 |
'expression' can be anything.
It's just any Pliant expression, and it will simply be evaluated at compile
time. |
| Message posted by maybe Marcus on 2002/05/02 21:26:39 |
| And what is a 'Pliant expression', precisely? |
| Message posted by maybe Hubert Tonneau on 2002/05/02 21:40:02 |
> And what is a 'Pliant expression', precisely?
Anything that is a Pliant tree at parser level.
Here are sample Pliant expressions:
12
a=15 or true # assuming that 'a' was previously declared as a global variable
{ gvar Int u := 3 ; for (gvar Int i) 1 5 { u *= i+4 } ; u }
fact:a=120 # still assuming that 'a' was previously declared as a global variable
(file_query "/tmp/foo" standard)=defined
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