Summary

[R7RS] Initial environment of a CHICKEN program should be empty

Metadata

• Id: be15e6a2c19b112ab7f2fbcef63179d187a1b363
• Trac id: 1861
• Type: defect
• Reporter: zaifir
• Owner:
• Cc:
• Status: new
• Component: unknown
• Estimated difficulty: easy
• Resolution:
• Priority: major
• Milestone: someday
• Version: 5.4.0
• Changetime: 2025-11-29 00:14:41 UTC
• Created: 2025-11-29 00:14:41 UTC
• Keywords:

Description

R7RS (§5.1) requires that no identifiers be bound in the initial environment of a program. Yet there seems to be no way to prevent CHICKEN from importing all of (chicken base) into a CHICKEN program. According to the Report, `print` should be unbound in the following program:

 (import (scheme base))
 
 (print "hello, world")

csc 5.4.0 compiles this (and the resulting binary runs) without an error, since `print` is in `(chicken base)`, which is automatically imported.

Another result of this asymmetry is that the import qualifiers `only`, `prefix`, `rename`, etc. are effectively useless for `(chicken base)` and `(scheme)`.

R7RS is right, at least for CHICKEN in r7rs mode: any identifiers used but not defined by a program should be explicitly imported.

Addendum: The wiki.call-cc.org page for `(chicken base)` suggests that the `-explicit-use` compiler option can be used to avoid "using" the module, but Bunny351 says this option is unrelated to this issue.