Re: Command Languages Versus Programming Languages

On 2 Apr 2024 08:26:14 GMT, Stefan Ram wrote:

ram@zedat.fu-berlin.de (Stefan Ram) wrote or quoted:
>

def diff( x ):
   return 1 if x == 'x' else 0 if type( x )is str else[ 'sum', diff( x[
   1 ]), diff( x[ 2 ])]
   if x[ 0 ]== 'sum' else None

 
  Oops! That was one long line starting with "return";
  it was wrapped by the newsreader, but is not correct Python anymore
  when wrapped this way.

It’s bloody horrible Python even when wrapped correctly. I think Python’s
version of the conditional expression is a complete abortion.

How about this, to at least get things the same way round as in the more
usual C-style conditional expression:

def diff(x) :
    return \
        [
            lambda :
                [
                    lambda :
                        [
                            lambda : None,
                            lambda : ['sum', diff(x[1]), diff(x[2])],
                        ][x[0] == 'sum'](),
                    lambda : 0,
                ][isinstance(x, str)](),
            lambda : 1,
        ][x == 'x']()
#end diff