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 ****************
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(eval '(define x 32) (interaction-environment)) x (eval '(define y 55)) y reference to undefined identifier: x > 55
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.
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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.