From 4ef1c7a10b7ae4a053995700fdff1a55d2166d8c Mon Sep 17 00:00:00 2001
From: Ben Greenman <benjaminlgreenman@gmail.com>
Date: Thu, 9 Jun 2016 02:24:59 -0400
Subject: [PATCH] [regexp] only check balanced parans in presence of pipes

---
 test/regexp-pass.rkt       | 26 ++++++++++++++++----------
 trivial/private/regexp.rkt | 26 ++++++++++++++------------
 trivial/untyped/regexp.rkt | 11 ++---------
 3 files changed, 32 insertions(+), 31 deletions(-)

diff --git a/test/regexp-pass.rkt b/test/regexp-pass.rkt
index d8c2acb..78a85ac 100644
--- a/test/regexp-pass.rkt
+++ b/test/regexp-pass.rkt
@@ -8,6 +8,11 @@
     trivial/regexp
     typed/rackunit)
 
+  ;; -- regexp
+  (let ()
+    ;; TODO (what groups does this return? re-read regexp spec)
+    (check-true (and (regexp: "^(\r|\n|(\r\n))") #t)))
+
   ;; -- regexp-match:
   (check-equal?
     (ann
@@ -308,17 +313,18 @@
     '("alot"))
 
   ;; -- pipes = take min groups
-  (check-equal?
-    (ann
-      (regexp-match: "^(a*)|(b*)$" "aaa")
-      (U #f (List String (U #f String) (U #f String))))
-    '("aaa" "aaa" #f))
+  ;;    2016-06-08: currently disabled
+  ;(check-equal?
+  ;  (ann
+  ;    (regexp-match: "^(a*)|(b*)$" "aaa")
+  ;    (U #f (List String (U #f String) (U #f String))))
+  ;  '("aaa" "aaa" #f))
 
-  (check-equal?
-    (ann
-      (regexp-match: "^(aa*)(c*)|(b*)$" "b")
-      (U #f (List String (U #f String) (U #f String) (U #f String))))
-    '("b" #f #f "b"))
+  ;(check-equal?
+  ;  (ann
+  ;    (regexp-match: "^(aa*)(c*)|(b*)$" "b")
+  ;    (U #f (List String (U #f String) (U #f String) (U #f String))))
+  ;  '("b" #f #f "b"))
 
   ;; -- nested gropus
   (check-equal?
diff --git a/trivial/private/regexp.rkt b/trivial/private/regexp.rkt
index 40e2af3..e6f392e 100644
--- a/trivial/private/regexp.rkt
+++ b/trivial/private/regexp.rkt
@@ -72,12 +72,14 @@
      [(null? (cdr alt*))
       (parse-groups-for-alt (car alt*) #:src stx)]
      [else
-      (define num-groups
-        (for/fold ([num-groups 0])
-                  ([alt (in-list alt*)])
-          (define ng+null* (parse-groups-for-alt alt #:src stx))
-          (+ num-groups (car ng+null*))))
-      (list num-groups (range num-groups))]))
+      ;(define num-groups
+      ;  (for/fold ([num-groups 0])
+      ;            ([alt (in-list alt*)])
+      ;    (define ng+null* (parse-groups-for-alt alt #:src stx))
+      ;    (+ num-groups (car ng+null*))))
+      (parse-groups-for-alt str #:src stx)
+      #f
+      #;(list num-groups (range num-groups))]))
 
   ;; Count the number of matched parentheses in a regexp pattern.
   ;; Raise an exception if there are unmatched parens.
@@ -88,9 +90,9 @@
       (if (> i last-index)
         (cond
          [(not (null? in-paren))
-          (group-error str (format "'(' at index ~a" (car in-paren)))]
+          (group-error stx str (format "'(' at index ~a" (car in-paren)))]
          [(unbox in-square?)
-          (group-error str (format "'[' at index ~a" (car in-paren)))]
+          (group-error stx str (format "'[' at index ~a" (car in-paren)))]
          [else
           (list num-groups null-idx*)])
         (if (unbox in-square?)
@@ -112,7 +114,7 @@
            [(#\))
             (cond
              [(null? in-paren)
-              (group-error str (format "')' at index ~a" i))]
+              (group-error stx str (format "')' at index ~a" i))]
              [(eq? #f (car in-paren))
               ;; Matched closing paren, but does not count as a group
               (loop (+ i 1) (cdr in-paren) num-groups null-idx*)]
@@ -129,9 +131,9 @@
                      (eq? #\\ (string-ref str (+ i 1))))
               (loop (+ i 3) in-paren num-groups null-idx*)
               (loop (+ i 2) in-paren num-groups null-idx*))]
-           [(#\|)
-            ;; Nope! Can't handle pipes
-            (error 'internal-error "Found '|' character in regexp string.")]
+           ;[(#\|)
+           ; ;; Nope! Can't handle pipes
+           ; (error 'internal-error "Found '|' character in regexp string.")]
            [else
             (loop (+ i 1) in-paren num-groups null-idx*)])))))
 
diff --git a/trivial/untyped/regexp.rkt b/trivial/untyped/regexp.rkt
index b851d20..43dfc0b 100644
--- a/trivial/untyped/regexp.rkt
+++ b/trivial/untyped/regexp.rkt
@@ -72,12 +72,8 @@
      [(null? (cdr alt*))
       (parse-groups-for-alt (car alt*) #:src stx)]
      [else
-      (define num-groups
-        (for/fold ([num-groups 0])
-                  ([alt (in-list alt*)])
-          (define ng+null* (parse-groups-for-alt alt #:src stx))
-          (+ num-groups (car ng+null*))))
-      (list num-groups (range num-groups))]))
+      (parse-groups-for-alt str #:src stx)
+      #f]))
 
   ;; Count the number of matched parentheses in a regexp pattern.
   ;; Raise an exception if there are unmatched parens.
@@ -129,9 +125,6 @@
                      (eq? #\\ (string-ref str (+ i 1))))
               (loop (+ i 3) in-paren num-groups null-idx*)
               (loop (+ i 2) in-paren num-groups null-idx*))]
-           [(#\|)
-            ;; Nope! Can't handle pipes
-            (error 'internal-error "Found '|' character in regexp string.")]
            [else
             (loop (+ i 1) in-paren num-groups null-idx*)])))))