Fix #233: make shl/shr use the direct left operand for type casting

nimterop/toastlib/exprparser.nim

@@ -379,18 +379,28 @@ proc processBinaryExpression(gState: State, node: TSNode, typeofNode: var PNode)
 
   result.add gState.getIdent(nimSym)
   let leftNode = gState.processTSNode(left, typeofNode)
+  var tyNode = typeofNode
 
   if typeofNode.isNil:
     typeofNode = nkCall.newTree(
       gState.getIdent("typeof"),
       leftNode
     )
+    tyNode = typeofNode
 
-  let rightNode = gState.processTSNode(right, typeofNode)
+  # Special case of setting the shift left/right type
+  # to be the type of the direct left operand
+  if binarySym in [">>", "<<"]:
+    tyNode = nkCall.newTree(
+      gState.getIdent("typeof"),
+      leftNode
+    )
+
+  let rightNode = gState.processTSNode(right, tyNode)
 
   result.add leftNode
   result.add nkCall.newTree(
-    typeofNode,
+    tyNode,
     rightNode
   )
   if binarySym == "/":
@@ -399,7 +409,7 @@ proc processBinaryExpression(gState: State, node: TSNode, typeofNode: var PNode)
     # So we need to emulate C here and cast the whole
     # expression to the type of the first arg
     result = nkCall.newTree(
-      typeofNode,
+      tyNode,
       result
     )
 

tests/include/tast2.h

@@ -35,6 +35,7 @@ extern "C" {
 #define EQ4 AVAL < BVAL
 #define EQ5 AVAL != BVAL
 #define EQ6 AVAL == BVAL
+#define SX_NEAR_ZERO (1.0f / (1 << 28))
 
 // testing integer out of long int range
 #define INT_FAST16_MIN (-9223372036854775807L-1)

tests/tast2.nim

@@ -134,6 +134,8 @@ assert EQ4 == (AVAL < BVAL)
 assert EQ5 == (AVAL != BVAL)
 assert EQ6 == (AVAL == BVAL)
 
+assert SX_NEAR_ZERO == 3.725290298461914e-09
+
 assert SIZEOF == 1
 
 assert COERCE == 645635670332'u64