Expr IStatementVisitor <Expr> .Visit(Statement.While statement)
{
return(Expr.Loop(
Expr.IfThenElse(
Expr.Dynamic(
Context.DynamicCache.GetConvertBinder(typeof(bool)),
typeof(bool),
statement.Test.Visit(this)),
Visit(statement.Body),
Expr.Break(scope.BreakLabel())),
scope.BreakLabel()));
}
public ByteCodeChunk VisitWhile(Statement.While statement)
{
var chunk = new ByteCodeChunk();
chunk.AddRange(VisitExpression(statement.Condition));
var body = VisitBlock(statement.Body);
chunk.AddInstruction(
statement.IsUntilLoop ? Instruction.JmpIfTrue : Instruction.JmpIfFalse,
body.Count + 9); // 9 is the size of the final JmpShort instruction.
chunk.AddRange(body);
chunk.AddInstruction(Instruction.JmpShort, -(chunk.Count + 9));
return(chunk);
}
public object VisitWhileStatement(Statement.While stmt)
{
// if statement to skip loop if conditions is not met
stmt.Condition.Accept(this);
addInstruction(0x04);
addInstruction(0x40);
addInstruction(0x03); // loop
addInstruction(0x40); // while returns void
stmt.Body.Accept(this);
stmt.Condition.Accept(this);
addInstruction(0x0D); // break if negated condition
addInstruction(ZERO); // TODO break only current
addInstruction(0x0b); // end loop
addInstruction(0x0b); // end if statement
return(null);
}
public object VisitWhileStatement(Statement.While statement)
{
try
{
while (IsTruthy(Evaluate(statement.condition)))
{
Execute(statement.body);
}
return(null);
}
catch (BreakException)
{
/* Don't do anything, this is used to break out of the loop when we
* encounter a break statement. */
}
return(null);
}
public object VisitWhileStatement(Statement.While stmt)
{
return(null);
}
public object VisitWhileStatement(Statement.While statement)
{
Resolve(statement.condition);
Resolve(statement.body);
return(null);
}
private Statement ForStatement()
{
try
{
loopDepth++;
Consume(TokenType.LEFT_PAREN, "Expect '(' after 'for'.");
Statement initialiser = null;
if (Match(TokenType.SEMICOLON))
{
}
else if (Match(TokenType.VAR))
{
initialiser = VarDeclaration();
}
else
{
initialiser = ExpressionStatement();
}
Expression condition = Expression();
if (!Check(TokenType.SEMICOLON))
{
condition = Expression();
}
Consume(TokenType.SEMICOLON, "Expect ';' after loop condition.");
Expression increment = null;
if (!Check(TokenType.RIGHT_PAREN))
{
increment = Expression();
}
Consume(TokenType.RIGHT_PAREN, "Expect ')' after for clauses.");
Statement body = Statement();
if (increment != null)
{
body = new Statement.Block(new List <Statement> {
body, new Statement.Expression(increment)
});
}
if (condition == null)
{
condition = new Expression.Literal(true);
}
body = new Statement.While(condition, body);
if (initialiser != null)
{
body = new Statement.Block(new List <Statement> {
initialiser, body
});
}
return(body);
}
finally
{
loopDepth--;
}
}
