int:compare

4 files changed, 59 insertions, 2 deletions

diff --git a/gen/src/int.erl b/gen/src/int.erl
index d3b5939..21ad7d3 100644
--- a/gen/src/int.erl
+++ b/gen/src/int.erl
@@ -1,7 +1,7 @@
 -module(int).
 -compile(no_auto_import).
 
--export([parse/1, to_string/1, to_base_string/2]).
+-export([parse/1, to_string/1, to_base_string/2, compare/2]).
 
 parse(A) ->
     gleam__stdlib:parse_int(A).
@@ -11,3 +11,18 @@ to_string(A) ->
 
 to_base_string(A, B) ->
     erlang:integer_to_binary(A, B).
+
+compare(A, B) ->
+    case A =:= B of
+        true ->
+            eq;
+
+        false ->
+            case A < B of
+                true ->
+                    lt;
+
+                false ->
+                    gt
+            end
+    end.
diff --git a/gen/test/int_test.erl b/gen/test/int_test.erl
index a50b5e6..0d3163e 100644
--- a/gen/test/int_test.erl
+++ b/gen/test/int_test.erl
@@ -1,7 +1,7 @@
 -module(int_test).
 -compile(no_auto_import).
 
--export([to_string/0, parse/0, to_base_string/0]).
+-export([to_string/0, parse/0, to_base_string/0, compare_test/0]).
 
 to_string() ->
     expect:equal(int:to_string(123), <<"123">>),
@@ -19,3 +19,11 @@ parse() ->
 to_base_string() ->
     expect:equal(int:to_base_string(100, 16), <<"64">>),
     expect:equal(int:to_base_string(-100, 16), <<"-64">>).
+
+compare_test() ->
+    expect:equal(int:compare(0, 0), eq),
+    expect:equal(int:compare(1, 1), eq),
+    expect:equal(int:compare(0, 1), lt),
+    expect:equal(int:compare(-2, -1), lt),
+    expect:equal(int:compare(2, 1), gt),
+    expect:equal(int:compare(-1, -2), gt).
diff --git a/src/int.gleam b/src/int.gleam
index 00571de..5eeece4 100644
--- a/src/int.gleam
+++ b/src/int.gleam
@@ -1,3 +1,5 @@
+import order
+
 pub enum NotAnInt =
   | NotAnInt
 
@@ -6,3 +8,14 @@ pub external fn parse(String) -> Result(Int, NotAnInt) = "gleam__stdlib" "parse_
 pub external fn to_string(Int) -> String = "erlang" "integer_to_binary"
 
 pub external fn to_base_string(Int, Int) -> String = "erlang" "integer_to_binary"
+
+pub fn compare(a, b) {
+  case a == b {
+  | True -> order:Eq
+  | False ->
+    case a < b {
+    | True -> order:Lt
+    | False -> order:Gt
+    }
+  }
+}
diff --git a/test/int_test.gleam b/test/int_test.gleam
index d5f0f58..77f48ba 100644
--- a/test/int_test.gleam
+++ b/test/int_test.gleam
@@ -1,5 +1,6 @@
 import expect
 import int
+import order
 
 pub fn to_string() {
   123
@@ -50,3 +51,23 @@ pub fn to_base_string() {
   |> int:to_base_string(_, 16)
   |> expect:equal(_, "-64")
 }
+
+pub fn compare_test() {
+  int:compare(0, 0)
+  |> expect:equal(_, order:Eq)
+
+  int:compare(1, 1)
+  |> expect:equal(_, order:Eq)
+
+  int:compare(0, 1)
+  |> expect:equal(_, order:Lt)
+
+  int:compare(-2, -1)
+  |> expect:equal(_, order:Lt)
+
+  int:compare(2, 1)
+  |> expect:equal(_, order:Gt)
+
+  int:compare(-1, -2)
+  |> expect:equal(_, order:Gt)
+}