ISWIM/Python/Haskell - Re: Rich kids are into COBOL

Toby Thain toby at
Sat Feb 28 10:24:01 CST 2015

On 28/02/15 9:01 AM, Paul Koning wrote:
>> On Feb 28, 2015, at 6:02 AM, Johnny Billquist <bqt at> wrote:
>> And here I was sitting, thinking they all originated with Algol…
> They did, of course; Algol after all is the first block structured
language, and most block structured languages since then copied its
approach to name and data scope. (Not all; for example, Python has scope
rules that are noticeably different.)

Python's lexical blocks follow the "offside rule" (as do Haskell's). 
This rule was originally described by Peter Landin in his 1966 paper 
"The Next 700 Programming Languages". (Wikipedia has more on ISWIM and 
the offside rule.)


> Then there was Algol 68, ...

> 	paul

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