[fpc-devel] Proposal: Multiple assignments

Mark Morgan Lloyd markMLl.fpc-devel at telemetry.co.uk
Fri Aug 6 11:34:18 CEST 2010

Sven Barth wrote:

>> Does _any_ language support that paradigm ?
> Python: [...]  Java:

Also Perl as (a, b) = (0, 0); I can't remember whether a single value on 
the RHS is expanded.

> Although "a=b=c" is more like "assign c to b and assign (the new value 
> of) b to a" (but it might work in C as well that way).

Please excuse a comment from a non-developer but I really don't like 
this form. I've coded a number of parsers for script languages etc. and 
in general provided that you don't allow multiple assignment you can 
always work out unambiguously whether you're looking at an assignment or 
a test for equality, even without mandating distinct tokens.

I think that the OP needs to research first whether what he is trying to 
do could be done by a typed constant assignment, or if there is some way 
of building on the associated semantics rather than attempting 
ill-considered mutilation of Pascal's underlying syntax.

Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]

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