Allow expressions such as `e2` as multiplication of `e * 2`

2 files changed, 11 insertions, 0 deletions

diff --git a/src/lex.rs b/src/lex.rs
index 1c686a1..da542d5 100644
--- a/src/lex.rs
+++ b/src/lex.rs
@@ -143,6 +143,12 @@ pub fn lexer(input: &str, prev_ans: Option<f64>) -> Result<Vec<Token>, CalcError
                                 &char_vec[..char_vec.chars().count()-1]
                             )));
                         }
+                    } else if CONSTANTS.get(&char_vec[..]).is_some() {
+                        result.push(CONSTANTS.get(&char_vec[..]).unwrap().clone());
+                        result.push(OPERATORS.get(&'*').unwrap().clone());
+                        char_vec.clear();
+                        num_vec.push(letter);
+                        last_char_is_op = false;
                     } else {
                         return Err(CalcError::Syntax(format!(
                             "Unexpected character '{}'",
diff --git a/src/main.rs b/src/main.rs
index 75c33bb..f5e5c59 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -259,4 +259,9 @@ mod tests {
         let evaled = eval_math_expression("9 + _ ", Some(0f64)).unwrap();
         assert_eq!(9., evaled);
     }
+    #[test]
+    fn eval_const_multiplication() {
+        let evaled = eval_math_expression("e2", None).unwrap();
+        assert_eq!(5.4365636569, evaled);
+    }
 }