From eb72be85415765d1538bdf6e3b06090614f7a6f7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Na=C3=AFm=20Favier?= <n@monade.li>
Date: Sun, 17 Jul 2022 12:32:28 +0200
Subject: [PATCH] lib/types: add `number`

For numbers that can be ints or floats.
---
 lib/types.nix | 42 +++++++++++++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 9 deletions(-)

diff --git a/lib/types.nix b/lib/types.nix
index 354714b28733..76001804e721 100644
--- a/lib/types.nix
+++ b/lib/types.nix
@@ -226,11 +226,11 @@ rec {
     };
 
     int = mkOptionType {
-        name = "int";
-        description = "signed integer";
-        check = isInt;
-        merge = mergeEqualOption;
-      };
+      name = "int";
+      description = "signed integer";
+      check = isInt;
+      merge = mergeEqualOption;
+    };
 
     # Specialized subdomains of int
     ints =
@@ -291,10 +291,34 @@ rec {
     port = ints.u16;
 
     float = mkOptionType {
-        name = "float";
-        description = "floating point number";
-        check = isFloat;
-        merge = mergeEqualOption;
+      name = "float";
+      description = "floating point number";
+      check = isFloat;
+      merge = mergeEqualOption;
+    };
+
+    number = either int float;
+
+    numbers = let
+      betweenDesc = lowest: highest:
+        "${builtins.toJSON lowest} and ${builtins.toJSON highest} (both inclusive)";
+    in {
+      between = lowest: highest:
+        assert lib.assertMsg (lowest <= highest)
+          "numbers.between: lowest must be smaller than highest";
+        addCheck number (x: x >= lowest && x <= highest) // {
+          name = "numberBetween";
+          description = "integer or floating point number between ${betweenDesc lowest highest}";
+        };
+
+      nonnegative = addCheck number (x: x >= 0) // {
+        name = "numberNonnegative";
+        description = "nonnegative integer or floating point number, meaning >=0";
+      };
+      positive = addCheck number (x: x > 0) // {
+        name = "numberPositive";
+        description = "positive integer or floating point number, meaning >0";
+      };
     };
 
     str = mkOptionType {