feat: do compile time math for range neq (#469)

* feat: do compile time math for range neq

* Update src/modules/expression/binop/range.rs

Co-authored-by: Maksym Hazevych <[email protected]>

* allow anything other than Num literal in range neq

* use usize instead of i64

* use isize instead of usize

---------

Co-authored-by: Maksym Hazevych <[email protected]>
Co-authored-by: Huw Walters <[email protected]>

src/modules/expression/binop/range.rs

@@ -1,11 +1,13 @@
+use std::ops::Sub;
 use heraclitus_compiler::prelude::*;
 use crate::docs::module::DocumentationModule;
-use crate::{handle_binop, error_type_match};
-use crate::modules::{expression::expr::Expr, types::{Type, Typed}};
+use crate::modules::expression::expr::{Expr, ExprType};
+use crate::modules::types::{Type, Typed};
 use crate::utils::metadata::ParserMetadata;
 use crate::translate::compute::{translate_computation, ArithOp};
 use crate::translate::module::TranslateModule;
 use crate::utils::TranslateMetadata;
+use crate::{handle_binop, error_type_match};
 use super::BinOp;
 
 #[derive(Debug, Clone)]
@@ -59,7 +61,11 @@ 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 = if let Some(ExprType::Number(_)) = &self.to.value {
+                to.parse::<isize>().unwrap_or_default().sub(1).to_string()
+            } else {
+                translate_computation(meta, ArithOp::Sub, Some(to), Some("1".to_string()))
+            };
             meta.gen_subprocess(&format!("seq {} {}", from, to_neq))
         } else {
             meta.gen_subprocess(&format!("seq {} {}", from, to))