Nullable values

Author: lpil

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.8.0 - 2023-09-22
+
+- The `nullable` function has been added.
+
 ## v0.7.0 - 2023-08-03
 
 - Updated syntax for Gleam v0.30.0.

gleam.toml

@@ -1,5 +1,5 @@
 name = "sqlight"
-version = "0.7.0"
+version = "0.8.0"
 licences = ["Apache-2.0"]
 description = "Use SQLite from Gleam!"
 

manifest.toml

@@ -3,11 +3,11 @@
 
 packages = [
   { name = "esqlite", version = "0.8.6", build_tools = ["rebar3"], requirements = [], otp_app = "esqlite", source = "hex", outer_checksum = "607E45F4DA42601D8F530979417F57A4CD629AB49085891849302057E68EA188" },
-  { name = "gleam_stdlib", version = "0.27.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "9DBDD21B48C654182CDD8AA15ACF85E8E74A0438583C68BD7EF08BE89F999C6F" },
-  { name = "gleeunit", version = "0.10.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "ECEA2DE4BE6528D36AFE74F42A21CDF99966EC36D7F25DEB34D47DD0F7977BAF" },
+  { name = "gleam_stdlib", version = "0.30.2", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "8D8BF3790AA31176B1E1C0B517DD74C86DA8235CF3389EA02043EE4FD82AE3DC" },
+  { name = "gleeunit", version = "0.11.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "1397E5C4AC4108769EE979939AC39BF7870659C5AFB714630DEEEE16B8272AD5" },
 ]
 
 [requirements]
-esqlite = "~> 0.8"
-gleam_stdlib = "~> 0.25"
-gleeunit = "~> 0.8"
+esqlite = { version = "~> 0.8" }
+gleam_stdlib = { version = "~> 0.25" }
+gleeunit = { version = "~> 0.8" }

src/sqlight.gleam

@@ -1,6 +1,7 @@
 import gleam/list
 import gleam/string
 import gleam/result
+import gleam/option.{None, Option, Some}
 import gleam/dynamic.{Decoder, Dynamic}
 
 pub type Connection
@@ -404,6 +405,16 @@ fn coerce_value(a: a) -> Value
 @external(javascript, "./sqlight_ffi.js", "exec")
 fn exec_(a: String, b: Connection) -> Result(Nil, Error)
 
+/// Convert a Gleam `Option` to an SQLite nullable value, to be used an argument
+/// to a query.
+///
+pub fn nullable(inner_type: fn(t) -> Value, value: Option(t)) -> Value {
+  case value {
+    Some(value) -> inner_type(value)
+    None -> null()
+  }
+}
+
 /// Convert a Gleam `Int` to an SQLite int, to be used an argument to a
 /// query.
 ///

test/sqlight_test.gleam

@@ -259,3 +259,23 @@ pub fn query_error_test() {
       dynamic.element(0, dynamic.int),
     )
 }
+
+pub fn bind_nullable_test() {
+  use conn <- connect()
+
+  let assert Ok([option.Some(12_345)]) =
+    sqlight.query(
+      "select ?",
+      conn,
+      [sqlight.nullable(sqlight.int, option.Some(12_345))],
+      dynamic.element(0, dynamic.optional(dynamic.int)),
+    )
+
+  let assert Ok([option.None]) =
+    sqlight.query(
+      "select ?",
+      conn,
+      [sqlight.nullable(sqlight.int, option.None)],
+      dynamic.element(0, dynamic.optional(dynamic.int)),
+    )
+}