CallFunction.cs

namespace Interpreter.Lib.BackEnd.Instructions;

public class CallFunction : Simple
{
    private readonly FunctionInfo _function;
    private readonly int _numberOfArguments;
        
    public CallFunction(FunctionInfo function, int number, int numberOfArguments, string left = null) :
        base(left, (null, null), "Call ", number)
    {
        _function = function;
        _numberOfArguments = numberOfArguments + Convert.ToInt32(function.MethodOf != null);
    }

    public override int Jump() => _function.Location;

    public override int Execute(VirtualMachine vm)
    {
        var frame = new Frame(Number + 1, vm.Frames.Peek());

        var i = 0;
        var args = new List<(string Id, object Value)>();
        while (i < _numberOfArguments)
        {
            args.Add(vm.Arguments.Pop());
            frame[args[i].Id] = args[i].Value;
            i++;
        }

        if (_function.MethodOf != null)
        {
            var obj = (Dictionary<string, object>) frame[_function.MethodOf];
            foreach (var (key, value) in obj)
            {
                frame[key] = value;
            }
        }

        vm.CallStack.Push(new Call(Number, _function, args, Left));
        vm.Frames.Push(frame);
        return _function.Location;
    }

    protected override string ToStringRepresentation() => Left == null
        ? $"Call {_function}, {_numberOfArguments}"
        : $"{Left} = Call {_function}, {_numberOfArguments}";
}