vedenza

>>> def pair(x, y): return lambda f: f(x,y)
...
>>> def first(z): return z(lambda x, y: x)
...
>>> def second(z): return z(lambda x, y: y)
...
>>> t = pair('foo', 'bar')
>>> first(t)
'foo'
>>> second(t)
'bar'
>>>

shamelessly copied and ported from scheme

Leaking abstractions

x[:] : x[::-1] = x[1:-1] : x[len(x)-2:0:-1]

Tertium datur

if (a) {
  [...]
}
else if (!a) {
  [...]
}
else {
  [...]
}

HTTP Errors Explained

Lesson 1: Error 404 is clearly illustrated here.

Understanding recursion, part 2

Recursion is not always direct, it can also be mutual.

Understanding recursion

In order to understand recursion, one must first understand recursion.