Fix bibtex parser handling of nested bracket values and escapes.

scribble-lib/scriblib/bibtex.rkt

@@ -125,14 +125,28 @@
   (define (read-braced-value ip)
     (read-char ip)
     (let loop ()
-      (define first-part (read-until (λ (c) (or (char=? c #\{) (char=? c #\})))
+      (define first-part (read-until (λ (c) (or (char=? c #\{) (char=? c #\})
+                                                (char=? c #\\)))
                                      ip))
       (match (peek-char ip)
         [#\{
-         (string-append first-part (read-value ip) (loop))]
+         (string-append first-part (read-braced-value ip) (loop))]
         [#\}
          (read-char ip)
-         first-part])))
+         first-part]
+        [#\\
+         (read-char ip)
+         (string-append first-part (read-maybe-bibtex-escape ip) (loop))])))
+
+  (define (read-maybe-bibtex-escape ip)
+    (match (peek-char ip)
+      [#\#
+       (read-char ip)
+       "#"]
+      [_
+       ;; unknown escape; probably latex
+       "\\"]))
+
 
   (define (read-value ip)
     (slurp-whitespace ip)

scribble-test/tests/scriblib/bibtex.escapes.txt

@@ -0,0 +1,5 @@
+Bibliography
+
+[1]A A\"uthor. Foo Bar $\Sigma$. fake, 2003. example.com#tag       
+[2]S. Hochreiter and J. Schmidhuber. Long Short-Term Memory. Neural
+   Computation 9(8), pp. 1735–1780, 1997.                          

scribble-test/tests/scriblib/bibtex.rkt

@@ -10,6 +10,7 @@
 
 (define-runtime-path normal-expected-path "bibtex.normal.txt")
 (define-runtime-path number-expected-path "bibtex.number.txt")
+(define-runtime-path escapes-expected-path "bibtex.escapes.txt")
 
 (define-syntax-rule (test-render* definer expected-path body generate-bibliography-id)
   (let ()
@@ -73,4 +74,9 @@
               (λ (~cite-id citet-id)
                 (citet-id "salib:starkiller")
                 (citet-id "cryptoeprint:2000:067")
-                (citet-id "Tobin-Hochstadt:2011fk"))))
+                (citet-id "Tobin-Hochstadt:2011fk")))
+
+ (test-render escapes-expected-path (#:style number-style)
+              (λ (~cite-id citet-id)
+                (citet-id "escape1")
+                (citet-id "hochreiter_long_1997"))))

scribble-test/tests/scriblib/example.bib

@@ -405,3 +405,11 @@ @mastersthesis{salib:starkiller
   month = "May",
   year = 2004
 }
+
+@article{escape1,
+     author = {A A\"uthor},
+     title  = "{Foo} {Bar} $\Sigma$",
+     year   = 2003,
+     journal = "fake",
+     url    = {example.com\#tag},
+}