Re: Operationalize orthogonality

From: Tony D <>
Date: 1 Jun 2006 14:37:49 -0700
Message-ID: <>

My favourite "unfortunate series of unforeseen interactions" is still the old FORTRAN DO-loop screw up that managed to lose a Viking Venus probe, apparently.

Consider the meaning of the FORTRAN sequence

       DO 20 I = 1, 100

* stuff here

Now consider the meaning of the following sequence

       DO 20 I = 1. 100

* stuff here

Now consider the following "features" of FORTRAN.

  1. White space is not significant
  2. There are no reserved words
  3. Variables are automatically declared for you on first use if you didn't bother explicitly declaring them
  4. An automatically declared variable beginning with letters other than I,J,K,L,M or N is assumed to be of type REAL
  5. A labelled CONTINUE statement that isn't addressed by a DO-loop is treated as a no-op

Now consider the proximity of , and . on the keyboard.


Gene Wirchenko wrote: [ with another excellent reason why PL/I should fall off the face of the earth ] Received on Thu Jun 01 2006 - 23:37:49 CEST

Original text of this message