Add Clamp To An Endless Range as a Ruby TIL

ruby/clamp-to-an-endless-range.md

@@ -0,0 +1,22 @@
+# Clamp To An Endless Range
+
+The
+[`Comparable#clamp`](https://ruby-doc.org/3.3.6/Comparable.html#method-i-clamp)
+method allows us to specify the bounds of a value we want. If the target value
+is between the bounds, then we get that value. Otherwise, we gets the nearest
+end of the bounds.
+
+We can even pass a range to `#clamp` instead of separate lower and upper bound
+values. Because Ruby has beginless and endless ranges, this gives us the
+ergonomics to, say, clamp to any non-negative value with a `0..` endless range.
+
+Here is what that looks like:
+
+```ruby
+> 22.clamp(0..)
+=> 22
+> (-33).clamp(0..)
+=> 0
+> 0.clamp(0..)
+=> 0
+```