Re: Fwd: Heritage of Lua syntax for multi-line strings and comments

[Claudio Grondi <claudio.grondi@...>]

Thank you much Roberto and Tom for the replies.

OK ... I see now that lack of experience with writing a parser makes it 
hard for me to anticipate eventual possible problems with using another 
combinations of characters to achieve a shorter and less obtrusive 
visual text representation while using proportional fonts for editing 
the code and "misusing" the available syntax for multiple kinds of 
string literals for the purpose of styling the code text in an editor 
with custom code highlighter.

By the way: on my journey to understanding the heritage and the "why" 
for design decisions I am now wondering why does Lua not went the path 
of allowing only single quotation mark for string literal definitions 
and not went the Python way of defining multi-line strings like:

' single line string with the option \
to split it over multiple lines '

''' multiline string
                                first level '''
''''' multiline string
                                second level '''''
''''''' multiline string
                                third level '''''''
...

With this approach (the single quotation is quite narrow and not 
obtrusive) the parsing should be simpler and ... it would have a nicer 
appearance (not so "edgy" and "stopping" as using [[ ]]) .


On 11/24/23 15:10, Roberto Ierusalimschy wrote:
> > instead of:
> > `--[[[[[        third level styled text comment    ]]]]]`
> As Tom already pointed out, that creates some ambiguities if we try
> to enclose text starting or ending with square bracktes.
>
>
> > or
> > `--['''[        third level styled text comment    ]''']`
> Compare:  a = x['']  versus  a = x[''[. We need some look-ahead to
> distinguish them.
>
>
> > or
> > `--[...[        third level styled text comment    ]...]`
> Again, compare: a = x[...]  versus a = x[...[.
>
> That said, '=' is as good as any other character that cannot follow
> '[' in regular Lua code. (Better yet if it cannot come before ']').
>
> Well, its symmetry is also a plus:
>
>    [>>>] text [>>>]  ??  [>>>[ text ]<<<]
>    [///] text [///]  ??  [///[ text ]\\\]
>
>    [***[ text ]***]    Sounds good
>
> -- Roberto