BinaryBooleanOperator.cs

using System;
using System.Threading.Tasks;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Exceptions;
using Waher.Script.Objects;
 
namespace Waher.Script.Model
{
    public abstract class BinaryBooleanOperator : BinaryScalarOperator
    {
        private bool? bothBool = null;
 
        public BinaryBooleanOperator(ScriptNode Left, ScriptNode Right, int Start, int Length, Expression Expression)
            : base(Left, Right, Start, Length, Expression)
        {
        }
 
        public override IElement Evaluate(Variables Variables)
        {
            IElement L;
            bool ScalarDirectly = false;
 
            try
            {
                L = this.left.Evaluate(Variables);
            }
            catch (Exception exLeft)
            {
                L = new ObjectValue(exLeft);
                ScalarDirectly = true;
            }
 
            BooleanValue BL = L as BooleanValue;
            BooleanValue BR;
            IElement Result;
            IElement R;
 
            if (this.bothBool.HasValue && this.bothBool.Value && !(BL is null))
            {
                bool LValue = BL.Value;
                Result = this.EvaluateOptimizedResult(LValue);
                if (!(Result is null))
                    return Result;
 
                try
                {
                    R = this.right.Evaluate(Variables);
                }
                catch (Exception exRight)
                {
                    R = new ObjectValue(exRight);
                    ScalarDirectly = true;
                }
 
                BR = R as BooleanValue;
 
                if (!(BR is null))
                    return this.Evaluate(LValue, BR.Value);
                else
                    this.bothBool = false;
            }
            else
            {
                try
                {
                    R = this.right.Evaluate(Variables);
                }
                catch (Exception exRight)
                {
                    R = new ObjectValue(exRight);
                    ScalarDirectly = true;
                }
 
                BR = R as BooleanValue;
 
                if (!(BL is null) && !(BR is null))
                {
                    if (!this.bothBool.HasValue)
                        this.bothBool = true;
 
                    return this.Evaluate(BL.Value, BR.Value);
                }
                else
                {
                    this.bothBool = false;
 
                    if (ScalarDirectly)
                        return this.EvaluateScalar(L, R, Variables);
                    else
                        return this.Evaluate(L, R, Variables);
                }
            }
 
            if (ScalarDirectly)
                return this.EvaluateScalar(L, R, Variables);
            else
                return this.Evaluate(L, R, Variables);
        }
 
        public override async Task<IElement> EvaluateAsync(Variables Variables)
        {
            if (!this.isAsync)
                return this.Evaluate(Variables);
 
            IElement L;
 
            try
            {
                L = await this.left.EvaluateAsync(Variables);
            }
            catch (Exception exLeft)
            {
                L = new ObjectValue(exLeft);
            }
 
            BooleanValue BL = L as BooleanValue;
            BooleanValue BR;
            IElement Result;
            IElement R;
 
            if (this.bothBool.HasValue && this.bothBool.Value && !(BL is null))
            {
                bool LValue = BL.Value;
                Result = await this.EvaluateOptimizedResultAsync(LValue);
                if (!(Result is null))
                    return Result;
 
                try
                {
                    R = await this.right.EvaluateAsync(Variables);
                }
                catch (Exception exRight)
                {
                    R = new ObjectValue(exRight);
                }
 
                BR = R as BooleanValue;
 
                if (!(BR is null))
                    return await this.EvaluateAsync(LValue, BR.Value);
                else
                    this.bothBool = false;
            }
            else
            {
                try
                {
                    R = await this.right.EvaluateAsync(Variables);
                }
                catch (Exception exRight)
                {
                    R = new ObjectValue(exRight);
                }
 
                BR = R as BooleanValue;
 
                if (!(BL is null) && !(BR is null))
                {
                    if (!this.bothBool.HasValue)
                        this.bothBool = true;
 
                    return await this.EvaluateAsync(BL.Value, BR.Value);
                }
                else
                {
                    this.bothBool = false;
                    return await this.EvaluateAsync(L, R, Variables);
                }
            }
 
            return await this.EvaluateAsync(L, R, Variables);
        }
 
        public override IElement EvaluateScalar(IElement Left, IElement Right, Variables Variables)
        {
            if (Left.AssociatedObjectValue is Exception exLeft)
            {
                if (Right.AssociatedObjectValue is Exception exRight)
                    return this.Evaluate(exLeft, exRight);
                else
                {
                    if (!(Right.AssociatedObjectValue is bool r)
                        && !Expression.TryConvert(Right.AssociatedObjectValue, out r))
                    {
                        throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                    }
 
                    return this.Evaluate(exLeft, r);
                }
            }
            else if (Right.AssociatedObjectValue is Exception exRight)
            {
                if (!(Left.AssociatedObjectValue is bool l) &&
                    !Expression.TryConvert(Left.AssociatedObjectValue, out l))
                {
                    throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                }
 
                return this.Evaluate(l, exRight);
            }
            else
            {
                if (!(Left.AssociatedObjectValue is bool l) &&
                    !Expression.TryConvert(Left.AssociatedObjectValue, out l))
                {
                    throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                }
 
                if (!(Right.AssociatedObjectValue is bool r)
                    && !Expression.TryConvert(Right.AssociatedObjectValue, out r))
                {
                    throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                }
 
                return this.Evaluate(l, r);
            }
        }
 
        public override async Task<IElement> EvaluateScalarAsync(IElement Left, IElement Right, Variables Variables)
        {
            if (Left.AssociatedObjectValue is Exception exLeft)
            {
                if (Right.AssociatedObjectValue is Exception exRight)
                    return await this.EvaluateAsync(exLeft, exRight);
                else
                {
                    if (!(Right.AssociatedObjectValue is bool r)
                        && !Expression.TryConvert(Right.AssociatedObjectValue, out r))
                    {
                        throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                    }
 
                    return await this.EvaluateAsync(exLeft, r);
                }
            }
            else if (Right.AssociatedObjectValue is Exception exRight)
            {
                if (!(Left.AssociatedObjectValue is bool l) &&
                    !Expression.TryConvert(Left.AssociatedObjectValue, out l))
                {
                    throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                }
 
                return await this.EvaluateAsync(l, exRight);
            }
            else
            {
                if (!(Left.AssociatedObjectValue is bool l) &&
                    !Expression.TryConvert(Left.AssociatedObjectValue, out l))
                {
                    throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                }
 
                if (!(Right.AssociatedObjectValue is bool r)
                    && !Expression.TryConvert(Right.AssociatedObjectValue, out r))
                {
                    throw new ScriptRuntimeException("Scalar operands must be boolean values.", this);
                }
 
                return await this.EvaluateAsync(l, r);
            }
        }
 
        public abstract IElement EvaluateOptimizedResult(bool Left);
 
        public abstract IElement Evaluate(bool Left, bool Right);
 
        public abstract IElement Evaluate(Exception Left, bool Right);
 
        public abstract IElement Evaluate(bool Left, Exception Right);
 
        public abstract IElement Evaluate(Exception Left, Exception Right);
 
        public virtual Task<IElement> EvaluateOptimizedResultAsync(bool Left)
        {
            return Task.FromResult(this.EvaluateOptimizedResult(Left));
        }
 
        public virtual Task<IElement> EvaluateAsync(bool Left, bool Right)
        {
            return Task.FromResult(this.Evaluate(Left, Right));
        }
 
        public virtual Task<IElement> EvaluateAsync(Exception Left, bool Right)
        {
            return Task.FromResult(this.Evaluate(Left, Right));
        }
 
        public virtual Task<IElement> EvaluateAsync(bool Left, Exception Right)
        {
            return Task.FromResult(this.Evaluate(Left, Right));
        }
 
        public virtual Task<IElement> EvaluateAsync(Exception Left, Exception Right)
        {
            return Task.FromResult(this.Evaluate(Left, Right));
        }
    }
}