public void Validate_Get_expr_yields_no_error_for_defined_variable()
{
// Arrange
//
// This is the method being referred to. The expression below roughly matches "Foo.to_string", where
// Foo is a defined Perlang class.
var name = new Token(TokenType.IDENTIFIER, "to_string", null, -1);
var identifier = new Expr.Identifier(name);
var getExpr = new Expr.Get(identifier, name);
var bindings = new Dictionary <Expr, Binding>
{
{ identifier, new ClassBinding(identifier, new PerlangClass("Foo", new List <Stmt.Function>())) }
};
var typeValidationErrors = new List <TypeValidationError>();
var warnings = new List <CompilerWarning>();
// Act
TypeValidator.Validate(
new List <Stmt> {
new Stmt.ExpressionStmt(getExpr)
},
error => typeValidationErrors.Add(error),
expr => bindings[expr],
warning => warnings.Add(warning)
);
// Assert
Assert.Empty(typeValidationErrors);
Assert.Empty(warnings);
}
public void Validate_Get_expr_yields_expected_error_for_undefined_variable()
{
// Arrange
var name = new Token(TokenType.IDENTIFIER, "foo", null, -1);
var identifier = new Expr.Identifier(name);
var getExpr = new Expr.Get(identifier, name);
var bindings = new Dictionary <Expr, Binding>
{
// A null TypeReference here is the condition that is expected to lead to an "undefined variable" error.
{ identifier, new VariableBinding(typeReference: null, 0, identifier) }
};
var typeValidationErrors = new List <TypeValidationError>();
var warnings = new List <CompilerWarning>();
// Act
TypeValidator.Validate(
new List <Stmt> {
new Stmt.ExpressionStmt(getExpr)
},
error => typeValidationErrors.Add(error),
expr => bindings[expr],
warning => warnings.Add(warning)
);
// Assert
Assert.Single(typeValidationErrors);
Assert.Matches(typeValidationErrors.Single().Message, "Undefined identifier 'foo'");
Assert.Empty(warnings);
}
public void Validate_Call_expr_does_something_useful()
{
// Arrange
var name = new Token(TokenType.IDENTIFIER, "to_string", null, 1);
var identifier = new Expr.Identifier(name);
var get = new Expr.Get(identifier, name);
var paren = new Token(TokenType.RIGHT_PAREN, ")", null, 1);
var callExpr = new Expr.Call(get, paren, new List <Expr>());
var bindings = new Dictionary <Expr, Binding>
{
{ identifier, new NativeClassBinding(identifier, typeof(string)) }
};
var typeValidationErrors = new List <TypeValidationError>();
var warnings = new List <CompilerWarning>();
// Act
TypeValidator.Validate(
new List <Stmt> {
new Stmt.ExpressionStmt(callExpr)
},
error => typeValidationErrors.Add(error),
expr => bindings[expr],
warning => warnings.Add(warning)
);
// Assert
Assert.Empty(typeValidationErrors);
Assert.Empty(warnings);
}
public VoidObject VisitIdentifierExpr(Expr.Identifier expr)
{
// Note: providing the defaultValue in the TryGetObjectValue() call here is critical, since we must be able
// to distinguish between "set to null" and "not set at all".
if (!IsEmpty(scopes) &&
scopes.Last().TryGetObjectValue(expr.Name.Lexeme, VariableBindingFactory.None) == null)
{
nameResolutionErrorHandler(new NameResolutionError("Cannot read local variable in its own initializer.", expr.Name));
}
ResolveLocalOrGlobal(expr, expr.Name);
return(VoidObject.Void);
}
public string VisitIdentifierExpr(Expr.Identifier expr)
{
return(expr.Name.Lexeme);
}