Add from-pairs to core. #683

This always creates a table, use `table/to-struct` to
create a struct.

CHANGELOG.md

@@ -1,6 +1,9 @@
 # Changelog
 All notable changes to this project will be documented in this file.
 
+## ??? - Unreleased
+- Add `from-pairs` to core.
+
 ## 1.15.5 - 2021-04-25
 - Add `declare-headers` to jpm.
 - Fix error using unix pipes on BSDs.

meson.build

@@ -20,7 +20,7 @@
 
 project('janet', 'c',
   default_options : ['c_std=c99', 'build.c_std=c99', 'b_lundef=false', 'default_library=both'],
-  version : '1.15.5')
+  version : '1.15.6')
 
 # Global settings
 janet_path = join_paths(get_option('prefix'), get_option('libdir'), 'janet')

src/boot/boot.janet

@@ -1525,6 +1525,15 @@
   (loop [k :keys dict] (array/push ret k (in dict k)))
   ret)
 
+(defn from-pairs
+  ``Takes a sequence of pairs and creates a table from each pair. The inverse of
+  `pairs` on a table.``
+  [ps]
+  (def ret @{})
+  (each [k v] ps
+    (put ret k v))
+  ret)
+
 (defn interpose
   `Returns a sequence of the elements of ind separated by
   sep. Returns a new array.`

src/conf/janetconf.h

@@ -5,9 +5,9 @@
 
 #define JANET_VERSION_MAJOR 1
 #define JANET_VERSION_MINOR 15
-#define JANET_VERSION_PATCH 5
+#define JANET_VERSION_PATCH 6
-#define JANET_VERSION_EXTRA ""
+#define JANET_VERSION_EXTRA "-dev"
-#define JANET_VERSION "1.15.5"
+#define JANET_VERSION "1.15.6-dev"
 
 /* #define JANET_BUILD "local" */