From b4f242193d22687ffa725248e680324b0574d440 Mon Sep 17 00:00:00 2001
From: Calvin Rose <calsrose@gmail.com>
Date: Sat, 26 Dec 2020 15:38:04 -0600
Subject: [PATCH] Improve hash function for numbers.

---
 CHANGELOG.md        |  3 +++
 src/boot/boot.janet | 10 ++++++----
 src/core/value.c    |  7 +++++++
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a4bcfec5..4288299f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 All notable changes to this project will be documented in this file.
 
 ## Unreleased - ???
+- Importing modules that start with `/` is now the only way to import from project root.
+  Before, this would import from / on disk.
+- Change hash function for numbers.
 - Improve error handling of `dofile`.
 
 ## 1.13.1 - 2020-12-13
diff --git a/src/boot/boot.janet b/src/boot/boot.janet
index cbdefdfd..df30fc86 100644
--- a/src/boot/boot.janet
+++ b/src/boot/boot.janet
@@ -815,7 +815,7 @@
     (sort-help a lo right by)
     (sort-help a left hi by))
   a)
-    
+
 (defn sort
   "Sort an array in-place. Uses quick-sort and is not a stable sort."
   [a &opt by]
@@ -2598,7 +2598,8 @@
   (unmarshal image load-image-dict))
 
 (defn- check-. [x] (if (string/has-prefix? "." x) x))
-(defn- not-check-. [x] (unless (string/has-prefix? "." x) x))
+(defn- not-check-. [x] (unless (or (string/has-prefix? "/" x) (string/has-prefix? "." x)) x))
+(defn- check-/ [x] (if (string/has-prefix? "/" x) x))
 
 (def module/paths
   ```
@@ -2634,8 +2635,8 @@
   (defn- find-prefix
     [pre]
     (or (find-index |(and (string? ($ 0)) (string/has-prefix? pre ($ 0))) module/paths) 0))
-  (def all-index (find-prefix ":all:"))
-  (array/insert module/paths all-index [(string ":all:" ext) loader not-check-.])
+  (def all-index (find-prefix ".:all:"))
+  (array/insert module/paths all-index [(string ".:all:" ext) loader check-/])
   (def sys-index (find-prefix ":sys:"))
   (array/insert module/paths sys-index [(string ":sys:/:all:" ext) loader not-check-.])
   (def curall-index (find-prefix ":cur:/:all:"))
@@ -2700,6 +2701,7 @@
 (undef mod-filter)
 (undef check-.)
 (undef not-check-.)
+(undef check-/)
 
 (def module/loading
   `Table mapping currently loading modules to true. Used to prevent
diff --git a/src/core/value.c b/src/core/value.c
index 1be7966c..8b45a397 100644
--- a/src/core/value.c
+++ b/src/core/value.c
@@ -261,6 +261,13 @@ int32_t janet_hash(Janet x) {
         case JANET_STRUCT:
             hash = janet_struct_hash(janet_unwrap_struct(x));
             break;
+        case JANET_NUMBER: {
+            uint64_t i = janet_u64(x);
+            uint32_t lo = (uint32_t)(i & 0xFFFFFFFF);
+            uint32_t hi = (uint32_t)(i >> 32);
+            hash = (int32_t)(hi ^ lo);
+            break;
+        }
         case JANET_ABSTRACT: {
             JanetAbstract xx = janet_unwrap_abstract(x);
             const JanetAbstractType *at = janet_abstract_type(xx);