From: Vivien Kraus via General Guile related discussions <guile-user@gnu.org>
To: guile-user@gnu.org
Subject: Syntax locations are ambiguous: can we track source 'offset' and 'length'?
Date: Tue, 03 Aug 2021 00:50:24 +0200 [thread overview]
Message-ID: <771a6e88782e288143be269b14751b761523e4c1.camel@planete-kraus.eu> (raw)
Dear guilers,
I’m playing with syntaxes as first-class objects, and I notice that the
syntax source location is ambiguous:
(syntax-case
(call-with-input-string "(a\r b)" read-syntax) ()
((a b)
(values (syntax-source #'a) (syntax-source #'b))))
=>
$1 = ((line . 0) (column . 1))
$2 = ((line . 0) (column . 1))
This is obviously because of #\return.
I am trying to use the guile reader to read scheme comments, in
addition to the syntax elements. I know with syntax-source where a
syntax object starts, and I can know where it ends by using a spying
soft port and re-reading it. However, the #\return ambiguity makes all
my efforts pointless.
In (system base lalr), the source location contains a filename, line
and column, but also an offset and length. However, these last 2 get
dropped in source-location->source-properties. I could not find out
whether this is relevant to read-syntax.
So, is there a way to track source offset and length for syntax
objects?
Best regards,
Vivien
next reply other threads:[~2021-08-02 22:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-02 22:50 Vivien Kraus via General Guile related discussions [this message]
2021-08-03 19:29 ` Syntax locations are ambiguous: can we track source 'offset' and 'length'? Linus Björnstam
2021-08-03 23:51 ` Vivien Kraus via General Guile related discussions
2021-08-04 1:20 ` Keith Wright
2021-08-04 10:01 ` Vivien Kraus via General Guile related discussions
2021-08-04 12:05 ` Ludovic Courtès
2021-08-04 12:25 ` Vivien Kraus via General Guile related discussions
2021-08-04 13:41 ` Ludovic Courtès
2021-08-04 14:09 ` Vivien Kraus via General Guile related discussions
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