feat: add nil predeclared identifier

shenyih0ng · Apr 17, 2024 · 25ffe39 · 25ffe39
1 parent 7850fbd
commit 25ffe39
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Showing 2 changed files with 5 additions and 2 deletions.
diff --git a/src/go-slang/lib/operators.ts b/src/go-slang/lib/operators.ts
@@ -126,15 +126,17 @@ function evaluateRelationalOp(
   left: any,
   right: any
 ): Result<boolean, InvalidOperationError> {
-  if (!isSameType(left, right)) {
+  const hasNil = left === undefined || right === undefined
+
+  if (!isSameType(left, right) && !hasNil) {
     return Result.fail(
       new InvalidOperationError(
         `${left} ${operator} ${right} (mismatched types ${_typeof(left)} and ${_typeof(right)})`
       )
     )
   }
 
-  if (_typeof(left) === 'heapObj') {
+  if (_typeof(left) === 'heapObj' && !hasNil) {
     if (operator !== '==' && operator !== '!=') {
       return Result.fail(
         new InvalidOperationError(

diff --git a/src/go-slang/lib/predeclared.ts b/src/go-slang/lib/predeclared.ts
@@ -22,6 +22,7 @@ export interface PredeclaredFunc {
 export const PREDECLARED_IDENTIFIERS: { [key: string]: any } = {
   true: true,
   false: false,
+  nil: undefined,
   'sync.WaitGroup': NewType.WaitGroup,
   'sync.Mutex': NewType.Mutex
 }