Add SQL array::add() function for adding unique items

Related to #1690

lib/src/fnc/array.rs

@@ -9,6 +9,26 @@ use crate::sql::array::Union;
 use crate::sql::array::Uniq;
 use crate::sql::value::Value;
 
+pub fn add((array, value): (Value, Value)) -> Result<Value, Error> {
+	match (array, value) {
+		(Value::Array(mut arr), Value::Array(other)) => {
+			for v in other.0 {
+				if !arr.0.iter().any(|x| *x == v) {
+					arr.0.push(v)
+				}
+			}
+			Ok(arr.into())
+		}
+		(Value::Array(mut arr), value) => {
+			if !arr.0.iter().any(|x| *x == value) {
+				arr.0.push(value)
+			}
+			Ok(arr.into())
+		}
+		_ => Ok(Value::None),
+	}
+}
+
 pub fn all((arg,): (Value,)) -> Result<Value, Error> {
 	match arg {
 		Value::Array(v) => Ok(v.iter().all(Value::is_truthy).into()),

lib/src/fnc/mod.rs

@@ -66,6 +66,7 @@ pub fn synchronous(ctx: &Context<'_>, name: &str, args: Vec<Value>) -> Result<Va
 	dispatch!(
 		name,
 		args,
+		"array::add" => array::add,
 		"array::all" => array::all,
 		"array::any" => array::any,
 		"array::append" => array::append,

lib/src/sql/function.rs

@@ -303,6 +303,7 @@ fn function_names(i: &str) -> IResult<&str, &str> {
 fn function_array(i: &str) -> IResult<&str, &str> {
 	alt((
 		alt((
+			tag("array::add"),
 			tag("array::all"),
 			tag("array::any"),
 			tag("array::append"),