From 1f1f7075a2bcb3cc9edb9b32ed5e74630cd02d71 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Mon, 25 May 2020 23:31:54 -0700
Subject: [PATCH] make splicing-tag nonsettable

---
 pollen/core.rkt                    | 6 +++---
 pollen/private/external/output.rkt | 4 ++--
 pollen/private/main-base.rkt       | 3 ++-
 pollen/scribblings/setup.scrbl     | 3 ---
 pollen/setup.rkt                   | 2 --
 pollen/template/html.rkt           | 2 +-
 6 files changed, 8 insertions(+), 12 deletions(-)

diff --git a/pollen/core.rkt b/pollen/core.rkt
index 250e1d2..46a2dfe 100644
--- a/pollen/core.rkt
+++ b/pollen/core.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 (require (for-syntax
           racket/base
-          "setup.rkt")
+          "private/splice.rkt")
          racket/match
          txexpr/base
          xml/path
@@ -120,7 +120,7 @@
 (define-syntax (when/splice stx)
   (syntax-case stx ()
     [(_ COND . BODY)
-     (with-syntax ([SPLICING-TAG (datum->syntax stx (setup:splicing-tag))])
+     (with-syntax ([SPLICING-TAG (datum->syntax stx splice-signal-tag)])
        #'(if COND
              (SPLICING-TAG . BODY) 
              (SPLICING-TAG)))]))
@@ -130,7 +130,7 @@
 (define-syntax (for/splice/base stx)
   (syntax-case stx ()
     [(_ ITERATORS . BODY)
-     (with-syntax ([SPLICING-TAG (datum->syntax stx (setup:splicing-tag))]
+     (with-syntax ([SPLICING-TAG (datum->syntax stx splice-signal-tag)]
                    [FORM (or (syntax-property stx 'form) #'for/list)])
        #'(apply SPLICING-TAG (FORM ITERATORS
                                    (SPLICING-TAG . BODY))))]))
diff --git a/pollen/private/external/output.rkt b/pollen/private/external/output.rkt
index c3ad429..ddc462f 100644
--- a/pollen/private/external/output.rkt
+++ b/pollen/private/external/output.rkt
@@ -1,7 +1,7 @@
 #lang racket/base
 (require racket/promise
          racket/contract/base
-         pollen/setup) ; to get splicing char
+         pollen/private/splice) ; to get splicing char
 #|
 161017:
 This is a slightly amended version of scribble/text/output
@@ -129,7 +129,7 @@ This version will also splice lists that begin with the splicing char.
     (define npfx (pfx+col (pfx+ pfx lpfx)))
     (set-mcar! pfxs npfx) (set-mcdr! pfxs 0)
     (if (list? c)
-        (let ([c (if (eq? (setup:splicing-tag) (car c)) ; patch to cooperate with splicing char
+        (let ([c (if (eq? splice-signal-tag (car c)) ; patch to cooperate with splicing char
                      (cdr c)
                      c)])
           (for ([c (in-list c)]) (loop c)))
diff --git a/pollen/private/main-base.rkt b/pollen/private/main-base.rkt
index 9ce4929..1b293bb 100644
--- a/pollen/private/main-base.rkt
+++ b/pollen/private/main-base.rkt
@@ -2,6 +2,7 @@
 (require (for-syntax racket/base
                      syntax/strip-context
                      "../setup.rkt"
+                     "splice.rkt"
                      "split-metas.rkt")
          racket/list
          "to-string.rkt"
@@ -23,7 +24,7 @@
 (define (stringify xs) (apply string-append (map to-string xs)))
 
 (define (parse xs-in parser-mode root-proc)
-  (define xs (splice (strip-leading-newlines xs-in) (setup:splicing-tag)))
+  (define xs (splice (strip-leading-newlines xs-in) splice-signal-tag))
   (cond
     [(eq? parser-mode default-mode-pagetree) (decode-pagetree xs)]
     [(eq? parser-mode default-mode-markup) (apply root-proc (remove-voids xs))] 
diff --git a/pollen/scribblings/setup.scrbl b/pollen/scribblings/setup.scrbl
index 62c3f88..2d10473 100644
--- a/pollen/scribblings/setup.scrbl
+++ b/pollen/scribblings/setup.scrbl
@@ -147,9 +147,6 @@ Both the names and the values of environment variables are case-insensitive, so
 @history[#:added "1.1"]}
 
 
-@defoverridable[splicing-tag symbol?]{Key used to signal that an X-expression should be spliced into its containing X-expression.}
-
-
 @defoverridable[poly-source-ext symbol?]{Extension that indicates a source file can target multiple output types.}
 
 
diff --git a/pollen/setup.rkt b/pollen/setup.rkt
index ee4e471..bc9662e 100644
--- a/pollen/setup.rkt
+++ b/pollen/setup.rkt
@@ -141,8 +141,6 @@
 
 (define-settable here-path-key 'here-path)
 
-(define+provide splicing-tag '@)
-
 (define-settable poly-source-ext 'poly) ; extension that signals source can be used for multiple output targets
 (define-settable poly-targets '(html)) ; current target applied to multi-output source files
 (define+provide current-poly-target (make-parameter (car (poly-targets))))
diff --git a/pollen/template/html.rkt b/pollen/template/html.rkt
index 58f11ca..5db1303 100644
--- a/pollen/template/html.rkt
+++ b/pollen/template/html.rkt
@@ -6,7 +6,7 @@
   (define paren-match (cadr matches))
   paren-match)
 
-(define splicing-tag (setup:splicing-tag))
+(define splicing-tag splice-signal-tag)
 
 (define (has-outer-splice-tag? x)
   (and (pair? x) (eq? (get-tag x) splicing-tag)))