Allow prefix minus.

1 files changed, 7 insertions, 7 deletions

diff --git a/src/parser.rs b/src/parser.rs
index c0f3a9b..4a87fda 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -46,23 +46,16 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_num(&mut self) -> Option<Num> {
-        let negative = self.symbol("-");
         let t = self.next()?;
         if t.contains('.') || t.contains('e') || t.contains('E') {
             let Ok(f) = f64::from_str(t) else {
                 return None;
             };
-            if negative {
-                return Some(eval::float(-f));
-            }
             return Some(eval::float(f));
         }
         let Ok(i) = i64::from_str(t) else {
             return None;
         };
-        if negative {
-            return Some(eval::int(-i));
-        }
         Some(eval::int(i))
     }
 
@@ -77,6 +70,13 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_fun(&mut self) -> bool {
+        if self.symbol("-") {
+            self.stack.push(Op::Op {
+                prec: 0,
+                eval: Box::new(|n| eval::int(0).sub(n)),
+            });
+            return true;
+        }
         if self.symbol("sin") {
             self.stack.push(Op::Op {
                 prec: 3,