A. Sundararajan's Weblog

No reserved words!

Came across Rémi Forax's blog entry titled Languages Evolution: introduction of new keywords. He proposes the idea of contextual keywords. i.e., keywords can be used as identifier in other places - which helps in introducing new keywords in a mature language - without breaking existing programs. I've renamed "enum" during JDK 5.0. I've seen others renaming of "assert" during 1.4. So, how about avoiding renaming - but, still have new (context sensitive) keywords....

Now, that reminds me of PL/I - no reserved words! PL/I's "keywords" are recognized only in context, and may otherwise be used as identifier elsewhere. I've never programmed in PL/I. My friend (who used to be a mainframe programmer) used to "scare" us by showing programs such as this one.

Interestingly, Smalltalk does not have reserved words at all. Sometimes it is said that Smalltalk has only 5 reserved words:

1. nil (null)
2. true
3. false
4. self (this)
5. super

But, it is possible to create methods even with these names!

( Oct 12 2006, 07:53:20 PM IST ) Permalink | | | | |

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