PorygonLang/src/Evaluator/Evaluator.cpp

#include "Evaluator.hpp"
#include "EvaluationException.hpp"
#include "BinaryEvaluation.cpp"
#include "../Script.hpp"

void Evaluator::Evaluate(BoundScriptStatement *statement) {
    EvaluateBlockStatement(statement);
}

void Evaluator::EvaluateStatement(BoundStatement *statement) {
    switch (statement->GetKind()){
        case BoundStatementKind ::Script: throw; // Should never happen
        case BoundStatementKind ::Block: return this -> EvaluateBlockStatement((BoundBlockStatement*)statement);
        case BoundStatementKind ::Expression: return this -> EvaluateExpressionStatement((BoundExpressionStatement*)statement);
    }
}

void Evaluator::EvaluateBlockStatement(BoundBlockStatement* statement) {
    for (auto s: statement->GetStatements()){
        this -> EvaluateStatement(s);
    }
}

void Evaluator::EvaluateExpressionStatement(BoundExpressionStatement *statement) {
    this->_scriptData->_lastValue = this -> EvaluateExpression(statement->GetExpression());
}

any *Evaluator::EvaluateExpression(BoundExpression *expression) {
    auto type = expression -> GetType();
    switch (type->GetClass()){
        case TypeClass ::Number:
        {
            auto numType = (NumericScriptType*)type;
            if (numType->IsAwareOfFloat()){
                if (numType->IsFloat()){
                    double d = this -> EvaluateFloatExpression(expression);
                    return new boost::any(d);
                } else{
                    long l = this -> EvaluateIntegerExpression(expression);
                    return new boost::any(l);
                }
            }
            break;
        }
    }
}

long Evaluator::EvaluateIntegerExpression(BoundExpression *expression) {
    auto exprType = expression->GetType();
    if (exprType->GetClass() != TypeClass::Number){
        throw EvaluationException("Can't evaluate expression as integer, it will not return a number.");
    }
    auto numType = (NumericScriptType*)exprType;
    if (numType->IsAwareOfFloat() && numType->IsFloat()){
        throw EvaluationException("Can't evaluate expression as integer, it will return a float, not an integer.");
    }
    switch (expression->GetKind()){
        case BoundExpressionKind ::LiteralInteger: return ((BoundLiteralIntegerExpression*)expression)->GetValue();
        case BoundExpressionKind ::Binary: return this -> EvaluateIntegerBinary((BoundBinaryExpression*)expression);

        case BoundExpressionKind ::LiteralFloat:
        case BoundExpressionKind ::LiteralString:
        case BoundExpressionKind ::LiteralBool:
        case BoundExpressionKind ::Bad:
            throw;
    }
}

double Evaluator::EvaluateFloatExpression(BoundExpression *expression) {
    return 0;
}

bool Evaluator::EvaluateBoolExpression(BoundExpression *expression) {
    return false;
}

std::string Evaluator::EvaluateStringExpression(BoundExpression *expression) {
    return std::__cxx11::string();
}

long Evaluator::EvaluateIntegerBinary(BoundBinaryExpression *expression) {
    long leftValue = this -> EvaluateIntegerExpression(expression->GetLeft());
    long rightValue = this -> EvaluateIntegerExpression(expression->GetRight());

    switch (expression->GetOperation()){
        case BoundBinaryOperation ::Addition: return leftValue + rightValue;
        case BoundBinaryOperation ::Subtraction: return leftValue - rightValue;
        case BoundBinaryOperation ::Multiplication: return leftValue * rightValue;
        case BoundBinaryOperation ::Division: return leftValue / rightValue;

        default:
            throw EvaluationException("Can't evaluate operation to integer");
    }
}

double EvaluateBinaryOperation(double l, double r, BoundBinaryOperation op){
    switch (op){
        case BoundBinaryOperation ::Addition: return l + r;
        case BoundBinaryOperation ::Subtraction: return l - r;
        case BoundBinaryOperation ::Multiplication: return l * r;
        case BoundBinaryOperation ::Division: return l / r;

        default:
            throw EvaluationException("Can't evaluate operation to float");
    }
}
double EvaluateBinaryOperation(double l, long r, BoundBinaryOperation op){
    switch (op){
        case BoundBinaryOperation ::Addition: return l + r;
        case BoundBinaryOperation ::Subtraction: return l - r;
        case BoundBinaryOperation ::Multiplication: return l * r;
        case BoundBinaryOperation ::Division: return l / r;

        default:
            throw EvaluationException("Can't evaluate operation to float");
    }
}
double EvaluateBinaryOperation(long l, double r, BoundBinaryOperation op){
    switch (op){
        case BoundBinaryOperation ::Addition: return l + r;
        case BoundBinaryOperation ::Subtraction: return l - r;
        case BoundBinaryOperation ::Multiplication: return l * r;
        case BoundBinaryOperation ::Division: return l / r;

        default:
            throw EvaluationException("Can't evaluate operation to float");
    }
}

double Evaluator::EvaluateFloatBinary(BoundBinaryExpression *expression) {
    auto left = expression->GetLeft();
    auto right = expression->GetRight();
    auto leftType = (NumericScriptType*)left->GetType();
    auto rightType = (NumericScriptType*)right->GetType();
    if (leftType->IsFloat()){
        double leftValue = this -> EvaluateFloatExpression(left);
        if (rightType->IsFloat()){
            double rightValue = this -> EvaluateFloatExpression(right);
            return EvaluateBinaryOperation(leftValue, rightValue, expression->GetOperation());
        } else{
            long rightValue = this -> EvaluateIntegerExpression(right);
            return EvaluateBinaryOperation(leftValue, rightValue, expression->GetOperation());
        }
    } else{
        long leftValue = this-> EvaluateIntegerExpression(left);
        // If the left is an integer, we know the right must be a float, otherwise we'd be evaluating as integer;
        double rightValue = this -> EvaluateFloatExpression(right);
        return EvaluateBinaryOperation(leftValue, rightValue, expression->GetOperation());
    }
}