/**
* Run the type checking analysis on an expression that is required to have the type specified by
* the expected parameter.
*/
Type require(TypeAnalysis typing, Type expected) {
Type t = analyze(typing);
if (t != expected) {
typing.report(new Failure(pos, "An expression of type " + expected + " was expected"));
return expected;
}
return t;
}
/**
* Run type checking analysis on this expression. The typing parameter provides access to the
* scope analysis phase (in particular, to the associated error handler), and the env parameter
* reflects the environment in which the expression is evaluated. Unlike scope analysis for
* statements, there is no return result here: an expression cannot introduce new variables in to
* a program, so the final environment will always be the same as the initial environment.
*/
public Type analyze(TypeAnalysis typing) {
Type lt = lhs.analyze(typing);
type = rhs.analyze(typing);
if (!lt.equal(type)) {
typing.report(
new Failure(pos, "Attempt to assign " + type + " value to variable of type " + lt));
}
return type;
}
