Method pullInvoke

src/main/java/wyil/check/FlowTypeCheck.java:2281–2309

(Expr.Invoke expr, boolean required, Typing typing, Environment environment)

	}

	private Typing pullInvoke(Expr.Invoke expr, boolean required, Typing typing, Environment environment) {
		// Extract link
		Decl.Link<Decl.Callable> link = expr.getLink();
		// Save argument expressions for later
		Tuple<Expr> arguments = expr.getOperands();
		final int n = arguments.size();
		// Select candidates with matching numbers of arguments
		List<Decl.Callable> candidates = select(link.getCandidates(), c -> c.getParameters().size() == n);
		// Check this invocation is resolvable
		if (!link.isPartiallyResolved() || candidates.size() == 0) {
			syntaxError(link.getName(), AMBIGUOUS_CALLABLE, link.getCandidates());
			return typing.invalidate();
		}
		// Allocate space for the signature variables. This is used to identify each row
		// in the typing matrix with one of candidates.
		typing = typing.push(Type.Any).push(Type.Any).push(Type.Any);
		int v_concrete = typing.top();
		int v_template = v_concrete - 1;
		int v_signature = v_concrete - 2;
		// Register a finaliser to resolve this invocation
		typing.register(typeInvokeExpression(expr, v_signature, v_template));
		// Fork typing into different cases for each overloaded candidate
		typing = typing
				.project(row -> fork(candidates, c -> initialiseCallableFrame(row, expr, c, v_signature, v_concrete, v_template)));
		// >>> Propagate forwards into children
		typing = pushExpressions(arguments, (r, i) -> getLambdaParameter(r.get(v_concrete), i), typing, environment);
		// Pull back return
		return typing.map(row -> row.add(getLambdaReturn(row.get(v_concrete))));
	}

	private Typing.Row initialiseCallableFrame(Typing.Row row, Expr.Invoke expr, Decl.Callable candidate, int v_signature,
			int v_concrete, int v_template) {