Upsilon/Upsilon/Binder/BoundStatements/BoundTableAssigmentStatement.cs

using System;
using System.Collections;
using System.Collections.Generic;
using Upsilon.BaseTypes;
using Upsilon.BaseTypes.ScriptTypeInterfaces;
using Upsilon.Evaluator;
using Upsilon.Text;

namespace Upsilon.Binder
{
    public class BoundTableAssigmentStatement : BoundStatement
    {
        public BoundExpression TableIndexExpression { get; }
        public BoundExpression Value { get; }

        public BoundTableAssigmentStatement(BoundExpression tableIndexExpression, BoundExpression value,
            TextSpan span) : base(span)
        {
            TableIndexExpression = tableIndexExpression;
            Value = value;
        }

        public override BoundKind Kind => BoundKind.BoundTableAssigmentStatement;

        public override IEnumerable<BoundNode> GetChildren()
        {
            yield return TableIndexExpression;
            yield return Value;
        }

        internal override void Evaluate(EvaluationScope scope, Diagnostics diagnostics, ref EvaluationState state)
        {
            ScriptType table;
            ScriptType index;
            if (TableIndexExpression.Kind == BoundKind.BoundIndexExpression)
            {
                var indexExpression = (BoundIndexExpression)TableIndexExpression;
                table = indexExpression.Identifier.Evaluate(scope, diagnostics, ref state);
                index = indexExpression.Index.Evaluate(scope, diagnostics, ref state);
            }
            else
            {
                var fullStopIndexExpression = (BoundFullStopIndexExpression) TableIndexExpression;
                table = fullStopIndexExpression.Expression.Evaluate(scope, diagnostics, ref state);
                index = fullStopIndexExpression.Index.ToScriptType();
            }

            var value = Value.Evaluate(scope, diagnostics, ref state);
            if (!(table is IIndexable indexable))
            {
                throw new Exception("Cant assign to that");
            }
            indexable.Set(diagnostics, Span, index.ToString().ToScriptType(), value);
        }

        internal override IEnumerator EvaluateCoroutine(EvaluationScope scope, Diagnostics diagnostics, EvaluationState state)
        {
            Evaluate(scope, diagnostics, ref state);
            yield break;
        }
    }
}