refactor(eval): rename math_constants to constants

src/math/eval.rs

@@ -1,7 +1,7 @@
 use rust_decimal::MathematicalOps;
 
 use crate::math::{
-    functions, math_constants,
+    constants, functions,
     types::{Expression, Operator},
 };
 
@@ -9,7 +9,7 @@ pub fn eval_expr(expr: Expression) -> Expression {
     match expr {
         Expression::Number(_) => expr,
         Expression::Variable(name) => {
-            if let Some(value) = math_constants::get(&name) {
+            if let Some(value) = constants::get(&name) {
                 Expression::Number(value)
             } else {
                 Expression::Variable(name)

src/math/mod.rs

@@ -3,11 +3,11 @@ use crate::math::types::Expression;
 #[cfg(test)]
 mod tests;
 
+mod constants;
 mod display;
 mod eval;
 mod functions;
 mod lexer;
-mod math_constants;
 mod parser;
 
 pub mod types;