NamedFuctionCall.cs

using System.Threading.Tasks;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.Script.Operators
{
    public class NamedFunctionCall : ScriptNode
    {
        private readonly string functionName;
        private readonly ScriptNode[] arguments;
        private readonly int nrArguments;
        private readonly bool nullCheck;
 
        public NamedFunctionCall(string FunctionName, ScriptNode[] Arguments, bool NullCheck, int Start, int Length, Expression Expression)
            : base(Start, Length, Expression)
        {
            this.functionName = FunctionName;
 
            this.arguments = Arguments;
            this.arguments?.SetParent(this);
 
            this.nullCheck = NullCheck;
            this.nrArguments = this.arguments.Length;
        }
 
        public string FunctionName => this.functionName;
 
        public ScriptNode[] Arguments => this.arguments;
 
        public override bool IsAsynchronous => true;
 
        public override IElement Evaluate(Variables Variables)
        {
            return this.EvaluateAsync(Variables).Result;
        }
 
        public override Task<IElement> EvaluateAsync(Variables Variables)
        {
            string s = this.nrArguments.ToString();
 
            if ((Variables.TryGetVariable(this.functionName + " " + s, out Variable v) ||
               Variables.TryGetVariable(this.functionName, out v)) &&
               v.ValueObject is ILambdaExpression f)
            {
                return this.EvaluateAsync(Variables, f);
            }
 
            if (Variables.TryGetVariable("Global", out v) &&
                v.ValueObject is Variables GlobalVariables &&
                (GlobalVariables.TryGetVariable(this.functionName + " " + s, out v) ||
               GlobalVariables.TryGetVariable(this.functionName, out v)) &&
               v.ValueObject is ILambdaExpression f2)
            {
                return this.EvaluateAsync(Variables, f2);
            }
 
            if (this.nullCheck)
                return Task.FromResult<IElement>(ObjectValue.Null);
            
            if (this.nrArguments == 1)
                throw new ScriptRuntimeException("No function defined having 1 argument named '" + this.functionName + "' found.", this);
            else
                throw new ScriptRuntimeException("No function defined having " + s + " arguments named '" + this.functionName + "' found.", this);
        }
 
        private async Task<IElement> EvaluateAsync(Variables Variables, ILambdaExpression f)
        { 
            IElement[] Arg = new IElement[this.nrArguments];
            ScriptNode Node;
            int i;
 
            for (i = 0; i < this.nrArguments; i++)
            {
                Node = this.arguments[i];
                if (Node is null)
                    Arg[i] = ObjectValue.Null;
                else
                    Arg[i] = await Node.EvaluateAsync(Variables);
            }
 
            if (f.IsAsynchronous)
                return await f.EvaluateAsync(Arg, Variables);
            else
                return f.Evaluate(Arg, Variables);
        }
 
        public override bool ForAllChildNodes(ScriptNodeEventHandler Callback, object State, SearchMethod Order)
        {
            int i;
 
            if (Order == SearchMethod.DepthFirst)
            {
                if (!this.arguments.ForAllChildNodes(Callback, State, Order))
                    return false;
            }
 
            ScriptNode Node;
 
            for (i = 0; i < this.nrArguments; i++)
            {
                Node = this.arguments[i];
                if (!(Node is null))
                {
                    bool b = !Callback(Node, out ScriptNode NewNode, State);
                    if (!(NewNode is null))
                    {
                        this.arguments[i] = Node = NewNode;
                        NewNode.SetParent(this);
                    }
 
                    if (b || (Order == SearchMethod.TreeOrder && !Node.ForAllChildNodes(Callback, State, Order)))
                        return false;
                }
            }
 
            if (Order == SearchMethod.BreadthFirst)
            {
                if (!this.arguments.ForAllChildNodes(Callback, State, Order))
                    return false;
            }
 
            return true;
        }
 
        public override bool Equals(object obj)
        {
            return obj is NamedFunctionCall O &&
                this.functionName.Equals(O.functionName) &&
                this.nullCheck.Equals(O.nullCheck) &&
                AreEqual(this.arguments, O.arguments) &&
                base.Equals(obj);
        }
 
        public override int GetHashCode()
        {
            int Result = base.GetHashCode();
            Result ^= Result << 5 ^ this.functionName.GetHashCode();
            Result ^= Result << 5 ^ this.nullCheck.GetHashCode();
            Result ^= Result << 5 ^ GetHashCode(this.arguments);
            return Result;
        }
    }
}