Actually, here's a testcase that's more representative of what I'm trying to do:

--------------------

(c-define (call-lambda l) (scheme-object) void "call_lambda" "" (l))

(define looper (c-lambda (scheme-object) void #<<c-lambda-end while(1){ call_lambda(___ARG1); } c-lambda-end ))

(define (main) (let ((e 1)) (looper (lambda () (set! e 2)))))

--------------------

It seems that modifying state outside the lambda causes it to crash (after looping a few times). This time I get:

*** ERROR IN looper -- Operator is not a PROCEDURE ('#<meroon #2>)

..which strikes me as a corrupted memory sort of error since I'm not doing anything with meroon.

Any pointers would be much appreciated.

Many thanks,

Phil

Phil Dawes wrote:

Hi Marc, Hi Gambit List,

I ran into problems using lambda expressions as callbacks when wrapping libcsv and I've boiled it down to this testcase. Can anybody tell me why this crashes?:

---

(c-define (call-lambda l) (scheme-object) void "call_lambda" "" (l))

(define looper (c-lambda (scheme-object) void #<<c-lambda-end while(1){ call_lambda(___ARG1); } c-lambda-end ))

(define (main) (looper (lambda () (write "foo"))))

---

looper is a c function which takes a scheme lambda and repeated invokes it using the 'call_lambda' bridging function.

When I gsc compile it and run '(main)' after a bunch of looping and printing it crashes with: ERROR IN looper -- Operator is not a PROCEDURE ('#<return #2>)

Any ideas? (or am I being stupid?!)

Many thanks,

Phil