From 41c1fa06dafb16f0720fb6de35071da08937bffb Mon Sep 17 00:00:00 2001
From: Chadtech <chadtech0@gmail.com>
Date: Sat, 16 Jan 2021 14:55:04 -0500
Subject: [PATCH] Beginning to implement Dict size

---
 compiler/builtins/bitcode/src/dict.zig |  6 ++++--
 compiler/builtins/bitcode/src/main.zig |  6 ++++++
 compiler/builtins/docs/Dict.roc        | 10 ++++++++--
 compiler/module/src/symbol.rs          |  1 +
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/compiler/builtins/bitcode/src/dict.zig b/compiler/builtins/bitcode/src/dict.zig
index a7327a4310..adb2863959 100644
--- a/compiler/builtins/bitcode/src/dict.zig
+++ b/compiler/builtins/bitcode/src/dict.zig
@@ -2,9 +2,8 @@ const std = @import("std");
 const testing = std.testing;
 const expectEqual = testing.expectEqual;
 
-
 const RocDict = struct {
-    len: u32,
+    size: usize,
 
     pub fn init() RocDict {
         return RocDict{
@@ -17,6 +16,9 @@ const RocDict = struct {
     }
 };
 
+pub fn dictSize(dict: RocDict) usize {
+    return dict.size;
+}
 
 test "RocDict.init() contains nothing" {
     const dict = RocDict.init();
diff --git a/compiler/builtins/bitcode/src/main.zig b/compiler/builtins/bitcode/src/main.zig
index 1106c2a5f6..8719eb85dd 100644
--- a/compiler/builtins/bitcode/src/main.zig
+++ b/compiler/builtins/bitcode/src/main.zig
@@ -2,6 +2,12 @@ const builtin = @import("builtin");
 const std = @import("std");
 const testing = std.testing;
 
+// Dict Module
+const dict = @import("dict.zig");
+comptime {
+    exportDictFn(dict.size, "size");
+}
+
 // Num Module
 const num = @import("num.zig");
 comptime {
diff --git a/compiler/builtins/docs/Dict.roc b/compiler/builtins/docs/Dict.roc
index 36056e81e5..c3a78b00df 100644
--- a/compiler/builtins/docs/Dict.roc
+++ b/compiler/builtins/docs/Dict.roc
@@ -1,7 +1,9 @@
-interface Dict2
+interface Dict
     exposes [ isEmpty, map ]
     imports []
 
+size : Dict * * -> Nat
+
 isEmpty : Dict * * -> Bool
 
 ## Convert each key and value in the #Dict to something new, by calling a conversion
@@ -13,4 +15,8 @@ isEmpty : Dict * * -> Bool
 ## 
 ## `map` functions like this are common in Roc, and they all work similarly.
 ## See for example #Result.map, #List.map, and #Set.map.
-map : List before, (before -> after) -> List after
+map :
+    Dict beforeKey beforeValue,
+    (\{ key: beforeKey, value: beforeValue } ->
+        { key: afterKey, value: afterValue }
+    ) -> Dict afterKey afterValue
diff --git a/compiler/module/src/symbol.rs b/compiler/module/src/symbol.rs
index efa7f13cc1..be66298b87 100644
--- a/compiler/module/src/symbol.rs
+++ b/compiler/module/src/symbol.rs
@@ -882,6 +882,7 @@ define_builtins! {
         3 DICT_SINGLETON: "singleton"
         4 DICT_GET: "get"
         5 DICT_INSERT: "insert"
+        6 DICT_SIZE: "size"
     }
     7 SET: "Set" => {
         0 SET_SET: "Set" imported // the Set.Set type alias