private void SemanticCheck(AssignStatement ast, CompilerContext context)
{
var valType = expressionTyper.TypeExpression(ast.Value, context);
var varExists = context.VariableExists(ast.VariableName);
//ast.CompilerScope = context.CurrentScope;
if (varExists)
{
var varType = context.GetVariableType(ast.VariableName);
if (varType != valType)
{
throw new TypingException($"bad assignment : {valType} expecting {varType}");
}
}
else
{
var creation = context.SetVariableType(ast.VariableName, valType);
ast.IsVariableCreation = creation;
ast.CompilerScope = context.CurrentScope;
}
}
public WhileType TypeExpression(Expression expr, CompilerContext context)
{
if (expr is BoolConstant b)
{
return(TypeExpression(b, context));
}
if (expr is IntegerConstant i)
{
return(TypeExpression(i, context));
}
if (expr is StringConstant s)
{
return(TypeExpression(s, context));
}
if (expr is BinaryOperation binary)
{
return(TypeExpression(binary, context));
}
if (expr is Neg neg)
{
return(TypeExpression(neg, context));
}
if (expr is Not not)
{
return(TypeExpression(not, context));
}
if (expr is Variable variable)
{
var varType = context.GetVariableType(variable.Name);
if (varType == WhileType.NONE)
{
throw new TypingException($" variable {variable.Name} {variable.Position} is not intialized");
}
variable.CompilerScope = context.CurrentScope;
return(varType);
}
throw new SignatureException($"unknow expression type ({expr.GetType().Name})");
}
