Fix overflows with operators (#904)

1 files changed, 4 insertions, 4 deletions

diff --git a/src/eval/ops.rs b/src/eval/ops.rs
index 43ee6ceb..48e74c8f 100644
--- a/src/eval/ops.rs
+++ b/src/eval/ops.rs
@@ -53,7 +53,7 @@ pub fn pos(value: Value) -> StrResult<Value> {
 /// Compute the negation of a value.
 pub fn neg(value: Value) -> StrResult<Value> {
     Ok(match value {
-        Int(v) => Int(-v),
+        Int(v) => Int(v.checked_neg().ok_or("value is too large")?),
         Float(v) => Float(-v),
         Length(v) => Length(-v),
         Angle(v) => Angle(-v),
@@ -70,7 +70,7 @@ pub fn add(lhs: Value, rhs: Value) -> StrResult<Value> {
         (a, None) => a,
         (None, b) => b,
 
-        (Int(a), Int(b)) => Int(a + b),
+        (Int(a), Int(b)) => Int(a.checked_add(b).ok_or("value is too large")?),
         (Int(a), Float(b)) => Float(a as f64 + b),
         (Float(a), Int(b)) => Float(a + b as f64),
         (Float(a), Float(b)) => Float(a + b),
@@ -137,7 +137,7 @@ pub fn add(lhs: Value, rhs: Value) -> StrResult<Value> {
 /// Compute the difference of two values.
 pub fn sub(lhs: Value, rhs: Value) -> StrResult<Value> {
     Ok(match (lhs, rhs) {
-        (Int(a), Int(b)) => Int(a - b),
+        (Int(a), Int(b)) => Int(a.checked_sub(b).ok_or("value is too large")?),
         (Int(a), Float(b)) => Float(a as f64 - b),
         (Float(a), Int(b)) => Float(a - b as f64),
         (Float(a), Float(b)) => Float(a - b),
@@ -165,7 +165,7 @@ pub fn sub(lhs: Value, rhs: Value) -> StrResult<Value> {
 /// Compute the product of two values.
 pub fn mul(lhs: Value, rhs: Value) -> StrResult<Value> {
     Ok(match (lhs, rhs) {
-        (Int(a), Int(b)) => Int(a * b),
+        (Int(a), Int(b)) => Int(a.checked_mul(b).ok_or("value is too large")?),
         (Int(a), Float(b)) => Float(a as f64 * b),
         (Float(a), Int(b)) => Float(a * b as f64),
         (Float(a), Float(b)) => Float(a * b),