Upsilon/Upsilon/Binder/BoundStatements/BoundFunctionAssignmentStatement.cs

using System.Collections;
using System.Collections.Generic;
using Upsilon.BaseTypes.ScriptFunction;
using Upsilon.Binder.VariableSymbols;
using Upsilon.Evaluator;
using Upsilon.Text;

namespace Upsilon.Binder
{
    public class BoundFunctionAssignmentStatement : BoundStatement
    {
        public VariableSymbol          Variable { get; }
        public BoundFunctionExpression Func     { get; }

        public BoundFunctionAssignmentStatement(VariableSymbol variable, BoundFunctionExpression func, TextSpan span): base(span)
        {
            Variable = variable;
            Func     = func;
        }

        public override BoundKind Kind => BoundKind.BoundFunctionAssignmentStatement;

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

        internal override void Evaluate(EvaluationScope scope, Diagnostics diagnostics, ref EvaluationState state)
        {
            var func = (ScriptRuntimeFunction)Func.Evaluate(scope, diagnostics, ref state);
            func.SetName(Variable.Name);
            if (Variable.Local)
            {
                if (scope.Variables.TryGetValue(Variable.Name, out var f) && f is ScriptRuntimeFunction scriptRuntimeFunction)
                {
                    scriptRuntimeFunction.AddOption(func.Options[0]);
                }
                else
                {
                    scope.CreateLocal(Variable, func);
                }
            }
            else
            {
                if (scope.TryGet(Variable, out var f) && f is ScriptRuntimeFunction scriptRuntimeFunction)
                {
                    scriptRuntimeFunction.AddOption(func.Options[0]);
                }
                else
                {
                    scope.AssignToNearest(Variable, func);
                }
            }

        }

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