/// <summary>
/// Creates a custom function definition given a name, parameter list, definition, and value expression.
/// </summary>
/// <param name="name">the name of the function</param>
/// <param name="args">the arguments to the function</param>
/// <param name="def">the definition of the function</param>
/// <param name="val">the expression that uses the function</param>
public CustomDefinitionExpression(string name, IReadOnlyList <VariableExpression> args, MathExpression def, MathExpression val)
{
FunctionName = name;
ParameterList = args;
Definition = def;
Value = val;
}
/// <summary>
/// Constructs a new <see cref="BinaryExpression"/> consisting of the specified arguments and type.
/// </summary>
/// <param name="left">the left argument</param>
/// <param name="right">the right argument</param>
/// <param name="type">the type of the expression</param>
public BinaryExpression(MathExpression left, MathExpression right, ExpressionType type)
{
if (type < ExpressionType.Add || type >= ExpressionType._Count)
{
throw new ArgumentException("Invalid ExpressionType value", nameof(type));
}
Type = type;
Arguments = new List <MathExpression> {
left, right
};
}
/// <summary>
/// Creates a custom function definition from a <see cref="BinaryExpression"/> of type
/// <see cref="BinaryExpression.ExpressionType.Equals"/> as the definition, and an expression
/// for the value.
/// </summary>
/// <param name="assignExpr">the expression to deconstruct for the name and arguments</param>
/// <param name="valueExpr">the expression to use as a <see cref="Value"/></param>
public CustomDefinitionExpression(BinaryExpression assignExpr, MathExpression valueExpr)
{
if (!(assignExpr is BinaryExpression bexp) || bexp.Type != BinaryExpression.ExpressionType.Equals)
{
throw new ArgumentException("Expected Equals expression");
}
var fn = bexp.Left;
if (!(fn is FunctionExpression func) || !func.IsUserDefined)
{
throw new ArgumentException("Left side of definition must be a prime function");
}
if (!func.Arguments.All(e => e is VariableExpression))
{
throw new ArgumentException("Left side of definition cannot contain arguments with expressions");
}
FunctionName = func.Name;
ParameterList = func.Arguments.Cast <VariableExpression>().ToList();
Definition = bexp.Right;
Value = valueExpr;
}
/// <summary> /// Compares this expression to the parameter for equality. /// </summary> /// <param name="other">the expression to compare to</param> /// <returns><see langword="true"/> if the two are equal, <see langword="false"/> otherwise</returns> public abstract bool Equals(MathExpression other);
/// <inheritdoc/> public override bool Equals(MathExpression other) => other is MemberExpression mem &&
/// <summary>
/// Constructs a new <see cref="MemberExpression"/> for a given target and member name.
/// </summary>
/// <param name="target">the target of the access</param>
/// <param name="member">the name of the member to access</param>
public MemberExpression(MathExpression target, string member)
{
Target = target;
MemberName = member;
}
/// <inheritdoc/> public override bool Equals(MathExpression other) => other is UnaryExpression e &&
/// <summary>
/// Constructs a new <see cref="UnaryExpression"/> of the specified type, with the given argument.
/// </summary>
/// <param name="type">the type of the expression</param>
/// <param name="arg">the argument of the expression</param>
public UnaryExpression(ExpressionType type, MathExpression arg)
{
Type = type;
Argument = arg;
}
/// <summary> /// Compares this expression to the parameter for equality. /// </summary> /// <param name="other">the expression to compare to</param> /// <returns><see langword="true"/> if the two are equal, <see langword="false"/> otherwise</returns> public override bool Equals(MathExpression other) => other is CustomDefinitionExpression cde &&
/// <inheritdoc/> public override bool Equals(MathExpression other) => other is VariableExpression v && v.Name == Name;
/// <inheritdoc/> public override bool Equals(MathExpression other) => other is FunctionExpression f &&