Robuuster returns in javascript.

scrbl/js-maker.scrbl

@@ -16,18 +16,10 @@
                   (list (verbatim rkt) (verbatim js)))))
 
 @title{js-maker: a Syntax-Driven Racket-to-JavaScript Generator}
-@author+email["Hans Dijkema" "hans@dijkewijk.nl"]
+@author+email["Hans Dijkema" ""]
 
 @defmodule[js-maker]
 
-This module has been largely coded as an evolution to the @tt{js-transformer} setup
-from @tt{racket-webview} by supervising it's evolution using AI.
-It is astonishing what AI can do these days. To get the AI agent this far
-on racket and testing the output by itself, I had to get @tt{racket} installed
-in the coding sandbox of the AI agent.
-See @hyperlink["https://racket.discourse.group/t/a-small-experiment-bootstrapping-racket-into-a-chatgpt-sandbox-at-openai/4238"]{the discourse article}
-about that. 
-
 @bold{js-maker} is a small, syntax-driven JavaScript generator for writing a
 practical JavaScript subset in Racket notation.  It provides two macros,
 @racket[js] and @racket[js/expression].  In the ordinary case the macros
@@ -70,13 +62,12 @@ function square(x) {
 Inside function bodies, the last expression is returned automatically unless it
 is already a statement form such as @racket[return], @racket[define],
 @racket[set!], @racket[while], or @racket[for].  At the top level of a
-@racket[js] form, js-maker also returns the value of a final value-producing
-form, such as @racket[let], @racket[begin], or @racket[if].  This makes
-@racket[js] output suitable as the body of a WebView @tt{runJavaScript}
-wrapper function.  A top-level @racket[with-handlers] is treated as a statement
-so that a catch handler used for side effects does not prematurely return from
-the surrounding wrapper.  Use @racket[js/expression] when the value of a
-@racket[with-handlers] form itself is needed.
+@racket[js] form, however, js-maker emits statement code and does not invent an
+implicit @tt{return}.  This keeps the generated code valid when it is handed
+directly to a WebView @tt{runJavaScript} or @tt{evaluateJavaScript} entry point,
+where a top-level JavaScript @tt{return} would be an @tt{Illegal return}
+syntax error.  Use @racket[js/expression] when a generated JavaScript value is
+needed.
 
 For example:
 
@@ -95,7 +86,7 @@ emits JavaScript similar to:
 {
   let el = document.getElementById("test");
   el.innerHTML = "<h1>Hi</h1>";
-  return true;
+  true;
 }
 }
 }
@@ -161,14 +152,15 @@ source text.
 #<<RKT
 (let ([x 10]
       [y 20])
-  (js (let ([a (inject (* x y))])
-        (return (* a a)))))
+  (js/expression
+   (let ([a (inject (* x y))])
+     (* a a))))
 RKT
 #<<JS
-{
+(() => {
   let a = 200;
   return (a * a);
-}
+})()
 JS
 )