From 23fccba08113d9bacc0a50e4925fbbda181d4d77 Mon Sep 17 00:00:00 2001
From: ben <types@ccs.neu.edu>
Date: Sun, 13 Dec 2015 03:54:52 -0500
Subject: [PATCH] [private] init

---
 private/README.md  |  5 +++++
 private/common.rkt | 12 ++++++++++++
 regexp.rkt         | 10 ++++------
 3 files changed, 21 insertions(+), 6 deletions(-)
 create mode 100644 private/README.md
 create mode 100644 private/common.rkt

diff --git a/private/README.md b/private/README.md
new file mode 100644
index 0000000..82e5bd0
--- /dev/null
+++ b/private/README.md
@@ -0,0 +1,5 @@
+private
+===
+
+Files that no law-abiding library user should `require`.
+- `common.rkt` Helper functions common to a few macros.
diff --git a/private/common.rkt b/private/common.rkt
new file mode 100644
index 0000000..bad38e0
--- /dev/null
+++ b/private/common.rkt
@@ -0,0 +1,12 @@
+#lang racket/base
+
+(provide
+  expand-expr
+  ;; (-> Syntax Syntax)
+  ;; Call local expand for an expression context with an empty list of stop-ids
+)
+
+;; =============================================================================
+
+(define (expand-expr stx)
+  (local-expand stx 'expression '()))
diff --git a/regexp.rkt b/regexp.rkt
index 06ce30d..f5b4b39 100644
--- a/regexp.rkt
+++ b/regexp.rkt
@@ -27,6 +27,7 @@
   racket/syntax
   syntax/id-table
   syntax/parse
+  trivial/private/common
 ))
 
 ;; =============================================================================
@@ -53,7 +54,7 @@
            [g:id
             (syntax/loc #'g f)]
            [(_ pat-stx)
-            #:with pat-stx+ (regexp-expand #'pat-stx)
+            #:with pat-stx+ (expand-expr #'pat-stx)
             #:with (num-groups . T) (count-groups #'pat-stx+)
             (syntax-property #'(f pat-stx+)
               num-groups-key
@@ -64,7 +65,7 @@
         (define-syntax define-f:
           (syntax-parser
            [(_ name:id pat-stx)
-            #:with pat-stx+ (regexp-expand #'pat-stx)
+            #:with pat-stx+ (expand-expr #'pat-stx)
             #:with (num-groups . T) (count-groups #'pat-stx+)
             (free-id-table-set! id+num-groups
                                 #'name
@@ -81,7 +82,7 @@
 (define-syntax regexp-match:
   (syntax-parser
    [(f pat-stx arg* ...)
-    #:with pat-stx+ (regexp-expand #'pat-stx)
+    #:with pat-stx+ (expand-expr #'pat-stx)
     #:with (num-groups . T) (count-groups #'pat-stx+)
     #:with (index* ...) #`#,(for/list ([i (in-range (syntax-e #'num-groups))]) i)
     #'(let ([maybe-match (regexp-match pat-stx+ arg* ...)])
@@ -105,9 +106,6 @@
     (format "Valid regexp pattern (contains unmatched ~a)" reason)
     str))
 
-(define-for-syntax (regexp-expand stx)
-  (local-expand stx 'expression '()))
-
 (define-for-syntax (quoted-stx-value? stx)
   (and
     (syntax? stx)