This site is a static rendering of the Trac instance that was used by R7RS-WG1 for its work on R7RS-small (PDF), which was ratified in 2013. For more information, see Home.

Source for wiki EvalDefine version 1

author

cowan

comment

ipnr

198.185.18.207

name

EvalDefine

readonly

text

R5RS does not require `eval` to accept definitions.  It also requires a second argument specifying the evaluation environment; invoking `(interaction-environment)` returns an environment object that represents the REPL environment.  I ran tests on the suite of Schemes to see what was supported where.





runallschemes define eval
****************************************************************************
*                                                                          *
*                                                                          *
*                                                                          *
*                                                                          *
*                                                                          *
*                              RUN ALL SCHEMES                             *
*                              define eval
*                                                                          *
*                                                                          *
*                                                                          *
*                                                                          *
*                                                                          *
****************************************************************************
===== RACKET =====
Welcome to Racket v5.1.3.
> (eval '(define x 32) (interaction-environment)) x (eval '(define y 55)) y
reference to undefined identifier: interaction-environment

 === context ===
/usr/local/lib/racket/collects/racket/private/misc.rkt:85:7

> reference to undefined identifier: x

 === context ===
/usr/local/lib/racket/collects/racket/private/misc.rkt:85:7

> > 55
> 
===== GAUCHE =====
gosh> (eval '(define x 32) (interaction-environment)) x (eval '(define y 55)) y
x
gosh> 32
gosh> *** ERROR: wrong number of arguments for #<subr eval> (required 2, got 1)
Stack Trace:
_______________________________________
gosh> *** ERROR: unbound variable: y
Stack Trace:
_______________________________________
gosh> ===== MIT =====
MIT/GNU Scheme running under GNU/Linux
Type `^C' (control-C) followed by `H' to obtain information about interrupts.

Copyright (C) 2011 Massachusetts Institute of Technology
This is free software; see the source for copying conditions. There is NO warranty; not even for
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Image saved on Thursday March 1, 2012 at 1:27:49 AM
  Release 9.1.1 || Microcode 15.3 || Runtime 15.7 || SF 4.41 || LIAR/i386 4.118 || Edwin 3.116

1 ]=> (eval '(define x 32) (interaction-environment)) x (eval '(define y 55)) y

;Unbound variable: interaction-environment
;To continue, call RESTART with an option number:
; (RESTART 3) => Specify a value to use instead of interaction-environment.
; (RESTART 2) => Define interaction-environment to a given value.
; (RESTART 1) => Return to read-eval-print level 1.

2 error> 
;Unbound variable: x
;To continue, call RESTART with an option number:
; (RESTART 4) => Specify a value to use instead of x.
; (RESTART 3) => Define x to a given value.
; (RESTART 2) => Return to read-eval-print level 2.
; (RESTART 1) => Return to read-eval-print level 1.

3 error> 
;The procedure #[compiled-procedure 11 ("global" #x35) #xf #x2d0dbf] has been called with 1 argument; it requires exactly 2 arguments.
;To continue, call RESTART with an option number:
; (RESTART 3) => Return to read-eval-print level 3.
; (RESTART 2) => Return to read-eval-print level 2.
; (RESTART 1) => Return to read-eval-print level 1.

time

2012-06-26 06:46:29