public Void Visit_BlockStmt(BlockStmt stmt)
{
BeginScope();
Resolve(stmt.statements);
EndScope();
return(null);
}
public object VisitBlockStmt(BlockStmt stmt)
{
BeginScope();
Resolve(stmt.Statements);
EndScope();
return(null);
}
// ForStatement -> "for" "(" ( varDecl | ExpressionStmt | ";" ) Expression? ";" Expression? ";" ")" Statement
private AstNode ForStatement()
{
Consume(TokenType.LEFT_PAREN, "Expect '(' after 'for'.");
AstNode initializer = default(AstNode);
if (!Match(TokenType.SEMICOLON))
{
initializer = Match(TokenType.VAR)
? VarDeclaration()
: ExpressionStatement();
}
AstNode condition = Check(TokenType.SEMICOLON) ? new LiteralExpr(true) : Expression();
Consume(TokenType.SEMICOLON, "Expect ';' after 'for' loop condition.");
AstNode increment = Check(TokenType.RIGHT_PAREN) ? null : Expression();
Consume(TokenType.RIGHT_PAREN, "Expect ')' after for clauses.");
AstNode body = Statement();
// Desugarize for loop
// From: for (var i = 0; i < 10; ++i) doStuff();
// To: var i = 0; while (i < 10) { doStuff(); i = i+1; }
if (increment != null)
{
body = new BlockStmt(new List <AstNode> {
body, new ExpressionStmt(increment)
});
}
body = new WhileStmt(condition, body);
if (initializer != null)
{
body = new BlockStmt(new List <AstNode> {
initializer, body
});
}
return(body);
}
public object VisitBlockStmt(BlockStmt stmt)
{
ExecuteBlock(stmt.Statements, new Scope(_scope));
return(null);
}
private Stmt ForStatement()
{
Expect(TokenType.LeftParen, ErrorType.ExpectedOpenParen);
Stmt initializer;
if (CheckCurrentToken(TokenType.Semicolon))
{
initializer = null;
Advance();
}
else if (CheckCurrentToken(TokenType.Var))
{
Advance();
initializer = VarDeclaration();
}
else
{
initializer = ExpressionStatement();
}
Expr condition = null;
if (!CheckCurrentToken(TokenType.Semicolon))
{
condition = Expression();
}
Expect(TokenType.Semicolon, ErrorType.ExpectedSemicolon);
Expr increment = null;
if (!CheckCurrentToken(TokenType.RightParen))
{
increment = Expression();
}
Expect(TokenType.RightParen, ErrorType.ExpectedClosedParen);
Stmt body = Statement();
if (increment != null)
{
body = new BlockStmt(new List <Stmt> {
body, new ExpressionStmt(increment)
});
}
if (condition == null)
{
condition = new LiteralExpr(true);
}
body = new WhileStmt(condition, body);
if (initializer != null)
{
body = new BlockStmt(new List <Stmt> {
initializer, body
});
}
return(body);
}
public Void Visit_BlockStmt(BlockStmt stmt)
{
ExecuteBlock(stmt.statements, new Environment(_environment));
return(null);
}
public string Visit_BlockStmt(BlockStmt stmt)
{
return(Parenthesize("Block", stmt.statements.ToArray()));
}