Implement ecmascript try/catch using
with-exception-handler/rais-exception respectively so that it is
straight-forward to interact with ecmascript exceptions from scheme.
* module/language/ecmascript/compile-tree-il.scm: Compile try/catch
* module/language/ecmascript/impl.scm: Provide js-try and js-catch
procedures
---
.../language/ecmascript/compile-tree-il.scm | 25 +++++++++++++++++++
module/language/ecmascript/impl.scm | 18 ++++++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)
diff --git a/module/language/ecmascript/compile-tree-il.scm
b/module/language/ecmascript/compile-tree-il.scm
index 074674142..6f6af5210 100644
--- a/module/language/ecmascript/compile-tree-il.scm
+++ b/module/language/ecmascript/compile-tree-il.scm
@@ -355,6 +355,31 @@
,(with-return-prompt
(lambda ()
(comp-body e body formals syms))))))))
+ ((try (block . ,body)
+ (catch ,err (block . ,catch))
+ ,finally)
+ (let ((err-sym (gensym (symbol->string err))))
+ `(call ,(@implv js-try)
+ (lambda ()
+ (lambda-case
+ ((() #f #f #f () ())
+ (begin ,@(map (lambda (x) (comp x e)) body)))))
+ (lambda ((,err . ,err-sym))
+ (lambda-case
+ (((,err) #f #f #f () (,err-sym))
+ ,(let ((e (econs err err-sym e)))
+ `(begin ,@(map (lambda (x) (comp x e)) catch))))))
+ (lambda ()
+ (lambda-case
+ ((() #f #f #f () ())
+ ,(pmatch/source finally
+ ((finally (block . ,finally))
+ `(begin ,@(map (lambda (x) (comp x e)) finally)))
+ (#f '(void))
+ (else (error "syntax error: invalid try statement: "
x)))))))))
+ ((throw ,expr)
+ `(call ,(@implv js-throw)
+ ,(comp expr e)))
((call/this ,obj ,prop . ,args)
(@impl call/this*
obj
diff --git a/module/language/ecmascript/impl.scm
b/module/language/ecmascript/impl.scm
index 27c077aed..b1be63403 100644
--- a/module/language/ecmascript/impl.scm
+++ b/module/language/ecmascript/impl.scm
@@ -33,7 +33,9 @@
shift
mod
band bxor bior
- make-enumerator))
+ make-enumerator
+ js-throw
+ js-try))
(define-class <js-module-object> (<js-object>)
@@ -87,6 +89,20 @@
(fluid-set! *this* (make <js-global-object>))
(init-js-bindings! (current-module)))))
+(define (js-throw obj)
+ (raise-exception obj #:continuable? #t))
+
+(define (js-try body-thunk catch-handler finally-thunk)
+ (with-exception-handler (lambda (e)
+ (catch-handler e)
+ (finally-thunk)
+ *undefined*)
+ (lambda ()
+ (body-thunk)
+ (finally-thunk)
+ *undefined*)
+ #:unwind? #t))
+
(define (get-this)
(fluid-ref *this*))
--
2.29.1
