/// <summary>
/// Private constructor
/// </summary>
private Inequality(Label id, IneqType type, LinearFunction lhs, LpNumber rhs, bool negFlag)
{
this.Id = id;
this.type = type;
this.lhs = lhs;
this.rhs = rhs;
this.NegFlag = negFlag;
}
/// <summary>
/// Private constructor
/// </summary>
private Inequality(Label id, IneqType type, LinearFunction lhs, LpNumber rhs, bool negFlag)
{
this.Id = id;
this.type = type;
this.lhs = lhs;
this.rhs = rhs;
this.NegFlag = negFlag;
}
/// <summary>
/// Parses an inequality
/// </summary>
/// <param name="scanner"></param>
/// <returns></returns>
public static Inequality ParseInequality(Scanner scanner)
{
Token t;
// Identifier
Label id = Label.ParseLabel(scanner);
// :
t = scanner.nextToken();
if (t.Type != TokenType.Colon)
{
throw new Exception(": expected: " + t);
}
// lhs
LinearFunction lhs = LinearFunction.ParseFunction(scanner);
// type
t = scanner.nextToken();
IneqType type;
switch (t.Type)
{
case TokenType.Le:
type = IneqType.Le;
break;
case TokenType.Ge:
type = IneqType.Ge;
break;
case TokenType.Eq:
type = IneqType.Eq;
break;
default:
throw new Exception("<=, =>, or = expected: " + t);
}
// rhs
t = scanner.nextToken();
if (t.Type != TokenType.Integer && t.Type != TokenType.Double)
{
throw new Exception("A number is expected: " + t);
}
LpNumber rhs = new LpNumber(decimal.Parse(t.StringValue));
return(new Inequality(id, type, lhs, rhs, false));
}
/// <summary>
/// Multiplication
/// </summary>
/// <param name="ineq"></param>
/// <param name="n"></param>
/// <returns></returns>
public static Inequality operator *(Inequality ineq, decimal n)
{
IneqType type = ineq.type;
bool newNegFlag = ineq.NegFlag;
if (n < 0)
{
newNegFlag = !newNegFlag;
if (type == IneqType.Le)
{
type = IneqType.Ge;
}
else if (type == IneqType.Ge)
{
type = IneqType.Le;
}
}
return(new Inequality(ineq.Id, type, ineq.lhs * n, ineq.rhs * n, newNegFlag));
}
/// <summary>
/// Multiplication
/// </summary>
/// <param name="ineq"></param>
/// <param name="n"></param>
/// <returns></returns>
public static Inequality operator *(Inequality ineq, decimal n)
{
IneqType type = ineq.type;
bool newNegFlag = ineq.NegFlag;
if (n < 0)
{
newNegFlag = !newNegFlag;
if (type == IneqType.Le)
type = IneqType.Ge;
else if (type == IneqType.Ge)
type = IneqType.Le;
}
return new Inequality(ineq.Id, type, ineq.lhs * n, ineq.rhs * n, newNegFlag);
}
/// <summary>
/// Parses an inequality
/// </summary>
/// <param name="scanner"></param>
/// <returns></returns>
public static Inequality ParseInequality(Scanner scanner)
{
Token t;
// Identifier
Label id = Label.ParseLabel(scanner);
// :
t = scanner.nextToken();
if (t.Type != TokenType.Colon)
throw new Exception(": expected: " + t);
// lhs
LinearFunction lhs = LinearFunction.ParseFunction(scanner);
// type
t = scanner.nextToken();
IneqType type;
switch (t.Type)
{
case TokenType.Le:
type = IneqType.Le;
break;
case TokenType.Ge:
type = IneqType.Ge;
break;
case TokenType.Eq:
type = IneqType.Eq;
break;
default:
throw new Exception("<=, =>, or = expected: " + t);
}
// rhs
t = scanner.nextToken();
if (t.Type != TokenType.Integer && t.Type != TokenType.Double)
throw new Exception("A number is expected: " + t);
LpNumber rhs = new LpNumber(decimal.Parse(t.StringValue));
return new Inequality(id, type, lhs, rhs, false);
}
