From 92d4a7fef47d878917f213c8719471856badbc9b Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Sun, 9 Aug 2015 12:04:15 -0700
Subject: [PATCH] ignore pollen cache files when making automatic pagetree
 (addresses #78)

---
 pagetree.rkt | 9 ++++++++-
 world.rkt    | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/pagetree.rkt b/pagetree.rkt
index bcd98d9..9a9d4eb 100644
--- a/pagetree.rkt
+++ b/pagetree.rkt
@@ -76,9 +76,16 @@
     (define (sort-names xs) (sort xs #:key ->string string<?))
     ;; put subdirs in list ahead of files (so they appear at the top)
     (append (sort-names subdirectories) (sort-names pagetree-sources) (sort-names other-files)))
+
+  ;; in general we don't filter the directory list for the automatic pagetree.
+  ;; this can be annoying sometimes but it's consistent with the policy of avoiding magic behavior.
+  ;; certain files (leading dot) will be ignored by `directory-list` anyhow.
+  ;; we will, however, ignore Pollen's cache files, because those shouldn't be project-manipulated.
+  (define (not-pollen-cache? path)
+    (not (member (->string path) world:cache-names)))
   
   (if (directory-exists? dir )
-      (decode-pagetree (map ->symbol (unique-sorted-output-paths (directory-list dir))))
+      (decode-pagetree (map ->symbol (unique-sorted-output-paths (filter not-pollen-cache? (directory-list dir)))))
       (error (format "directory->pagetree: directory ~a doesn't exist" dir)))) 
 
 ;; Try loading from pagetree file, or failing that, synthesize pagetree.
diff --git a/world.rkt b/world.rkt
index 3bb9ac1..1b02955 100644
--- a/world.rkt
+++ b/world.rkt
@@ -45,6 +45,7 @@
 
 (define-settable cache-filename "pollen.cache")
 (define-settable cache-dir-name "pollen-cache")
+(define cache-names (list (current-cache-filename) (current-cache-dir-name)))
 
 (define-settable decodable-extensions (list (current-markup-source-ext) (current-pagetree-source-ext)))