Allow nanopass parsers without run-time dependency

Removed np-parse-fail-token as a run-time dependency by making it a macro.
The whole parser really needs to be revisited, but this should make it
possible to generate compilers with intermediate language parser that do
not have a run-time dependency on the nanopass framework.
  nanopass/parser.ss, nanopass/helpers.ss,
  nanopass/implementation-helpers.chezscheme.sls,
  nanopass/implementation-helpers.ikarus.ss,
  nanopass/implementation-helpers.ironscheme.sls,
  nanopass/implementation-helpers.vicare.sls# Please enter the commit message for your changes. Lines starting

LOG

@@ -820,3 +820,13 @@ LATEST
     nano-syntax-dispatch) library.  With this change the pattern no longer
     needs to be quoted in the output of define-parser.
       nanopass/nano-syntax-dispatch.ss, nanopass/parser.ss
+2020-10-18 -
+  * Removed np-parse-fail-token as a run-time dependency by making it a macro.
+    The whole parser really needs to be revisited, but this should make it
+    possible to generate compilers with intermediate language parser that do
+    not have a run-time dependency on the nanopass framework.
+      nanopass/parser.ss, nanopass/helpers.ss,
+      nanopass/implementation-helpers.chezscheme.sls,
+      nanopass/implementation-helpers.ikarus.ss,
+      nanopass/implementation-helpers.ironscheme.sls,
+      nanopass/implementation-helpers.vicare.sls

nanopass/helpers.ss

@@ -58,9 +58,6 @@
     ;; the base record, so that we can use gensym syntax
     define-nanopass-record
 
-    ;; failure token so that we can know when parsing fails with a gensym
-    np-parse-fail-token
-
     ;; handy syntactic stuff
     with-implicit with-r6rs-quasiquote with-extended-quasiquote
     extended-quasiquote with-auto-unquote

nanopass/implementation-helpers.chezscheme.sls

@@ -49,9 +49,6 @@
     ;; the base record, so that we can use gensym syntax
     define-nanopass-record
 
-    ;; failure token so that we can know when parsing fails with a gensym
-    np-parse-fail-token
-
     ;; handy syntactic stuff
     with-implicit
 
@@ -75,9 +72,6 @@
                    (nongenerative #{nanopass-record d47f8omgluol6otrw1yvu5-0})
                    (fields (immutable tag nanopass-record-tag))))])))
 
-  ;; another gensym listed into this library
-  (define np-parse-fail-token '#{np-parse-fail-token dlkcd4b37swscag1dvmuiz-13})
-
   ;; the following should get moved into Chez Scheme proper (and generally
   ;; cleaned up with appropriate new Chez Scheme primitives for support)
   (define regensym

nanopass/implementation-helpers.ikarus.ss

@@ -49,9 +49,6 @@
     ;; the base record, so that we can use gensym syntax
     define-nanopass-record
 
-    ;; failure token so that we can know when parsing fails with a gensym
-    np-parse-fail-token
-
     ;; handy syntactic stuff
     with-implicit
 
@@ -80,9 +77,6 @@
                    (nongenerative #{nanopass-record d47f8omgluol6otrw1yvu5-0})
                    (fields (immutable tag nanopass-record-tag))))])))
 
-  ;; another gensym listed into this library
-  (define np-parse-fail-token '#{np-parse-fail-token dlkcd4b37swscag1dvmuiz-13})
-
   (define-syntax eq-hashtable-set! (identifier-syntax hashtable-set!))
   (define-syntax eq-hashtable-ref (identifier-syntax hashtable-ref))
 

nanopass/implementation-helpers.ironscheme.sls

@@ -49,9 +49,6 @@
     ;; the base record, so that we can use gensym syntax
     define-nanopass-record
 
-    ;; failure token so that we can know when parsing fails with a gensym
-    np-parse-fail-token
-
     ;; handy syntactic stuff
     with-implicit
 
@@ -89,10 +86,6 @@
                    (nongenerative nanopass-record-d47f8omgluol6otrw1yvu5-0)
                    (fields (immutable tag nanopass-record-tag))))])))
 
-  ;; another gensym listed into this library
-  ;; what is this used for?
-  (define np-parse-fail-token 'np-parse-fail-token-dlkcd4b37swscag1dvmuiz-13)
-
   (define-syntax eq-hashtable-set! (identifier-syntax hashtable-set!))
   (define-syntax eq-hashtable-ref (identifier-syntax hashtable-ref))
 

nanopass/implementation-helpers.vicare.sls

@@ -48,9 +48,6 @@
     ;; the base record, so that we can use gensym syntax
     define-nanopass-record
 
-    ;; failure token so that we can know when parsing fails with a gensym
-    np-parse-fail-token
-
     ;; handy syntactic stuff
     with-implicit
 
@@ -84,9 +81,6 @@
                    (nongenerative #{nanopass-record d47f8omgluol6otrw1yvu5-0})
                    (fields (immutable tag nanopass-record-tag))))])))
 
-  ;; another gensym listed into this library
-  (define np-parse-fail-token '#{np-parse-fail-token dlkcd4b37swscag1dvmuiz-13})
-
   (define-syntax eq-hashtable-set! (identifier-syntax hashtable-set!))
   (define-syntax eq-hashtable-ref (identifier-syntax hashtable-ref))
 

nanopass/parser.ss

@@ -8,6 +8,15 @@
           (nanopass syntaxconvert)
           (nanopass nano-syntax-dispatch))
 
+  (define-syntax np-parse-fail-token
+    (let ([sym (datum->syntax #'* (gensym "np-parse-fail-token"))])
+      (make-variable-transformer
+        (lambda (x)
+          (syntax-case x ()
+            [id (identifier? #'id) (with-syntax ([sym sym]) #''sym)]
+            [(set! _ e) (syntax-violation 'np-parse-fail-token "misplaced use of keyword" x)]
+            [(_ e ...) (syntax-violation 'np-parse-fail-token "misplaced use of keyword" x)])))))
+
   (define-syntax parse-or
     (syntax-rules (on-error)
       [(_ (on-error ?err0)) ?err0]