From: author@will.party
To: 58001@debbugs.gnu.org
Subject: bug#58001: Cannot use 'read' in imported library
Date: Thu, 22 Sep 2022 00:30:40 -0700 [thread overview]
Message-ID: <4VOLIR.1V2A6YW618L42@will.party> (raw)
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I'm using Guile version 3.0.5 from the Guix repository.
I've run into a strange issue with the read function from (scheme
base). It cannot be used in an R7RS-style library. This only seems to
apply to the read function. Other standard procedures work fine.
Let's say you have a library that uses read. Maybe it looks like this:
;; File: foo.scm
(define-library (foo)
(import (scheme base))
(export read-wrapped)
(begin
(define (read-wrapped port) (read port))))
Now, let's say you want to import that library somewhere else and use
it's exported function read-wrapped:
;; File: main.scm
(import (scheme base))
(import (foo))
(display (read (current-input-port)))
(display (read-wrapped (current-input-port)))
If you try to run that main script (in the same directory as the foo
library):
GUILE_LOAD_PATH=. guile --r7rs main.scm
You can enter get a datum for the first call to read, then you'll get
an error for the second call:
foo.scm:1:0: In procedure read-wrapped:
Unbound variable: read
This only happens with read. If you replace read with a different
standard procedure like boolean? then everything is fine (you'll see #f
twice because the input port fails the predicate).
I'm pretty baffled. I've attached the dummy source files for
convenience.
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[-- Attachment #2.1: foo.scm --]
[-- Type: text/x-scheme, Size: 127 bytes --]
(define-library (foo)
(import (scheme base))
(export read-wrapped)
(begin
(define (read-wrapped port) (read port))))
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[-- Attachment #2.2: main.scm --]
[-- Type: text/x-scheme, Size: 123 bytes --]
(import (scheme base))
(import (foo))
(display (read (current-input-port)))
(display (read-wrapped (current-input-port)))
reply other threads:[~2022-09-22 7:30 UTC|newest]
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