feat: do compile time math for range neq #469
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b1ek
requested review from
Mte90,
CymDeveloppement,
Ph0enixKM,
mks-h and
KrosFire
| @@ -59,7 +60,11 @@ impl TranslateModule for Range { | |||
| let from = self.from.translate(meta); | |||
| let to = self.to.translate(meta); | |||
| if self.neq { | |||
| let to_neq = translate_computation(meta, ArithOp::Sub, Some(to), Some("1".to_string())); | |||
| let to_neq = match &self.to.value.as_ref().unwrap() { | |||
| ExprType::Number(_) => (to.parse::<i64>().unwrap() - 1_i64).to_string(), | |||
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Is there any specific reason to use i64 over isize?
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Yes, a little. The isize type is adaptive to any bitness of the target architecture — it will be 32-bit on a 32-bit machine, and 64-bit on a 64-bit machine. The i64 type can be made to work on a 32-bit arch, but it will have a performance overhead.
I know we aren't really targeting 32-bit machines, but it won't hurt to keep the codebase a little bit more universal. Especially if it is this simple to do.
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That's precisely the reason why I use usize instead of u64 everywhere in the Amber compiler and Heraclitus
|
Other than these two nitpicks, LGTM. |
Co-authored-by: Maksym Hazevych <dpadar@protonmail.com>
| ExprType::VariableGet(_) => translate_computation(meta, ArithOp::Sub, Some(to), Some("1".to_string())), | ||
| _ => unreachable!("range expression must be either Number or VariableGet"), |
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It's not that simple, we should be able to do this kind of things:
0..(var + 10)
just instead of specifing VariableGet as the only acceptable expression other than Number, allow for any other expression. Compiler checks if it has correct Num type, so we're safe here
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Exactly. @b1ek look at the line 13 where a struct is defined. We have left and right arm that are expressions:
#[derive(Debug, Clone)]
pub struct Range {
from: Box<Expr>,
to: Box<Expr>,
neq: bool
}
We can't narrow the arms to variable get and number literal. This should literally expect any expression just like before we did.
| ExprType::VariableGet(_) => translate_computation(meta, ArithOp::Sub, Some(to), Some("1".to_string())), | ||
| _ => unreachable!("range expression must be either Number or VariableGet"), |
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Exactly. @b1ek look at the line 13 where a struct is defined. We have left and right arm that are expressions:
#[derive(Debug, Clone)]
pub struct Range {
from: Box<Expr>,
to: Box<Expr>,
neq: bool
}
We can't narrow the arms to variable get and number literal. This should literally expect any expression just like before we did.
amber:
0..2from:
$(seq 0 $(echo 2 '-' 1 | bc -l | sed '/\./ s/\.\{0,1\}0\{1,\}$//'))to:
$(seq 0 1)(when the
tois a number literal, if its a variable it will generate as before)