Replace prim__getArgs with prim__getArgsCount and prim__getArg

This spares us from having to build Idris data structures in the foreign
code.

libs/base/System.idr

@@ -31,15 +31,23 @@ export
 usleep : HasIO io => (x : Int) -> So (x >= 0) => io ()
 usleep sec = primIO (prim__usleep sec)
 
--- This one is going to vary for different back ends. Probably needs a
--- better convention. Will revisit...
-%foreign "scheme:blodwen-args"
-         "node:lambda:() => __prim_js2idris_array(process.argv.slice(1))"
-prim__getArgs : PrimIO (List String)
+-- Get the number of arguments
+%foreign "scheme:blodwen-arg-count"
+         "node:lambda:() => process.argv.length" 
+prim__getArgCount : PrimIO Int
+
+-- Get argument number `n`
+%foreign "scheme:blodwen-arg"
+         "node:lambda:n => process.argv[n]" 
+prim__getArg : Int -> PrimIO String
 
 export
 getArgs : HasIO io => io (List String)
-getArgs = primIO prim__getArgs
+getArgs = do
+            n <- primIO prim__getArgCount
+            if n > 0 
+              then for [0..n-1] (\x => primIO $ prim__getArg x)
+              else pure []
 
 %foreign libc "getenv"
          "node:lambda: n => process.env[n]"

support/chez/support.ss

@@ -358,12 +358,12 @@
 (define (blodwen-clock-second time) (time-second time))
 (define (blodwen-clock-nanosecond time) (time-nanosecond time))
 
-(define (blodwen-args)
-  (define (blodwen-build-args args)
-    (if (null? args)
-        (vector 0) ; Prelude.List
-        (vector 1 (car args) (blodwen-build-args (cdr args)))))
-    (blodwen-build-args (command-line)))
+
+(define (blodwen-arg-count)
+  (length (command-line)))
+
+(define (blodwen-arg n)
+  (if (< n (length (command-line))) (list-ref (command-line) n) ""))
 
 (define (blodwen-hasenv var)
   (if (eq? (getenv var) #f) 0 1))

support/gambit/support.scm

@@ -174,12 +174,12 @@
 (define (blodwen-time)
   (exact-floor (time->seconds (current-time))))
 
-(define (blodwen-args)
-  (define (blodwen-build-args args)
-    (if (null? args)
-        (vector 0) ; Prelude.List
-        (vector 1 (car args) (blodwen-build-args (cdr args)))))
-  (blodwen-build-args (cdr (command-line))))
+
+(define (blodwen-arg-count)
+  (length (command-line)))
+
+(define (blodwen-arg n)
+  (if (< n (length (command-line))) (list-ref (command-line) n) ""))
 
 (define (blodwen-hasenv var)
   (if (getenv var #f) 1 0))

support/racket/support.rkt

@@ -409,14 +409,13 @@
 (define (blodwen-clock-second time) (time-second time))
 (define (blodwen-clock-nanosecond time) (time-nanosecond time))
 
-(define (blodwen-args)
-  (define (blodwen-build-args args)
-    (if (null? args)
-        (vector 0) ; Prelude.List
-        (vector 1 (car args) (blodwen-build-args (cdr args)))))
-    (blodwen-build-args
-      (cons (path->string (find-system-path 'run-file))
-            (vector->list (current-command-line-arguments)))))
+
+(define (blodwen-arg-count)
+  (vector-length (current-command-line-arguments)))
+
+(define (blodwen-arg n)
+  (if (< n (vector-length (current-command-line-arguments)))
+       (vector-ref (current-command-line-arguments) n) ""))
 
 (define (blodwen-system cmd)
   (if (system cmd)