private static IObject EvalWhileExpression(Ast.WhileExpression we, Environment env)
{
var condition = Eval(we.Condition, env);
if (IsError(condition))
{
return(condition);
}
IObject result = Null;
while (IsTruthy(condition))
{
result = Eval(we.Consequence, env);
condition = Eval(we.Condition, env);
}
return(result);
}
private Ast.WhileExpression ParseWhileExpression()
{
var expression = new Ast.WhileExpression()
{
Token = _curToken
};
NextToken();
expression.Condition = ParseExpression(Precedence.Lowest);
if (!ExpectPeek(TokenType.Lbrace))
{
return(null);
}
expression.Consequence = ParseBlockStatement();
return(expression);
}
