/**
* This routine is called to determine if the right type is assignment compatible with the
* left-hand side. When this is called, we already know that there is a non-undefined type on the
* left-hand side. Now we need to make sure that the right-hand side is compatible with it, as
* described in the semantics notes in the Dijkstra specification.
*
* @param left
* @param right
*/
void checkAssignCompatible(LatteAST left, LatteAST right) {
boolean assignOK = false;
LatteType leftType = left.getNodeType();
LatteType rightType = right.getNodeType();
switch (leftType) {
case tINT:
case tFLOAT:
case tNUM:
assignOK = rightType == tINT || rightType == tFLOAT || rightType == tNUM;
break;
case tBOOLEAN:
assignOK = rightType == tBOOLEAN;
break;
case tCHAR:
assignOK = rightType == tCHAR;
break;
}
if (!assignOK) {
throw new LatteException(
"Incompatible assignment types: (" + leftType + "," + rightType + ")");
}
}
/**
* Set the node's type and also update the binding, if there is one (if the new type is not
* undefined).
*
* @param node the AST node
* @param type the type to assign to the node and binding
*/
void setNodeTypeAndMaybeBinding(LatteAST node, LatteType type) {
node.setNodeType(type);
if (type != tUNDEFINED && node.getBinding() != null) {
node.getBinding().setType(type);
}
}
/**
* This is an imperitive command to set the node type and its binding to the specified type.
* Calling this method means that the caller assumes the responsibility for ensuring that there is
* a binding corresponding to the node and that the type there is appropriate. This is used mainly
* for declarations where there is no doubt about the types.
*
* @param node the AST node
* @param type the type to assign to the node and binding
*/
void setNodeTypeAndBinding(LatteAST node, LatteType type) {
node.setNodeType(type);
node.getBinding().setType(type);
}