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From: Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups: comp.lang.c
Subject: Re: Top 10 most common hard skills listed on resumes...
Date: Sun, 01 Sep 2024 06:30:21 -0700
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Bart <bc@freeuk.com> writes:

> On 31/08/2024 23:10, Tim Rentsch wrote:
>
>> Bart <bc@freeuk.com> writes:
[...]
>>> Given this:
>>>
>>>     x + y = z;
>>>     (x + y) = z;
>>>
>>> My compiler produces the same AST for the LHS of '=' in both
>>> cases.
>>
>> To understand why they are different, try drawing parse trees
>> rather than abstract syntax trees.
>>
>> https://en.wikipedia.org/wiki/Parse_tree
>
> Yeah, the CST differs in retaining the parentheses.  But I can
> already see that from the source code.
>
> For normal compilation, that information is redundant.

The parse trees are different in a lot more ways than whether
one keeps parentheses.  But the point is to compare the parse
tree for x + y = z to the abstract syntax tree for x + y = z.
Among other things, the input x + y = z doesn't even have a
parse tree;  the rules governing the formation of parse trees
don't allow any parse tree matching that entire input.