Corrected patterns.md to use discard pattern ('_') in examples instead of star (*). (#610)

This commit is contained in:
Eik Rentzow 2017-06-05 21:57:57 +02:00 committed by Neal Gafter
parent b5cc2c882d
commit 236dff2783

View file

@ -256,7 +256,7 @@ And now we can operate on `Cartesian` values using polar coordinates
```cs ```cs
var c = Cartesian(3, 4); var c = Cartesian(3, 4);
if (c is Polar(var R, *)) Console.WriteLine(R); if (c is Polar(var R, _)) Console.WriteLine(R);
``` ```
Which prints `5`. Which prints `5`.
@ -468,7 +468,7 @@ Expr Deriv(Expr e)
{ {
switch (e) { switch (e) {
case X(): return Const(1); case X(): return Const(1);
case Const(*): return Const(0); case Const(_): return Const(0);
case Add(var Left, var Right): case Add(var Left, var Right):
return Add(Deriv(Left), Deriv(Right)); return Add(Deriv(Left), Deriv(Right));
case Mult(var Left, var Right): case Mult(var Left, var Right):
@ -485,8 +485,8 @@ An expression simplifier demonstrates positional patterns:
Expr Simplify(Expr e) Expr Simplify(Expr e)
{ {
switch (e) { switch (e) {
case Mult(Const(0), *): return Const(0); case Mult(Const(0), _): return Const(0);
case Mult(*, Const(0)): return Const(0); case Mult(_, Const(0)): return Const(0);
case Mult(Const(1), var x): return Simplify(x); case Mult(Const(1), var x): return Simplify(x);
case Mult(var x, Const(1)): return Simplify(x); case Mult(var x, Const(1)): return Simplify(x);
case Mult(Const(var l), Const(var r)): return Const(l*r); case Mult(Const(var l), Const(var r)): return Const(l*r);
@ -508,7 +508,7 @@ var areas =
case Line l: 0, case Line l: 0,
case Rectangle r: r.Width * r.Height, case Rectangle r: r.Width * r.Height,
case Circle c: Math.PI * c.Radius * c.Radius, case Circle c: Math.PI * c.Radius * c.Radius,
case *: throw new ApplicationException() case _: throw new ApplicationException()
) )
select new { Primitive = primitive, Area = area }; select new { Primitive = primitive, Area = area };
``` ```