From ec0c28fa741c397c5213c716874d80ef6b0c71bf Mon Sep 17 00:00:00 2001
From: Micha de Vries <micha@devrie.sh>
Date: Thu, 15 Aug 2024 10:17:00 +0200
Subject: [PATCH] `.chain()` method (#4513)

---
 core/src/fnc/mod.rs    |  3 +++
 core/src/fnc/shared.rs | 16 ++++++++++++++++
 lib/tests/function.rs  |  4 +++-
 3 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 core/src/fnc/shared.rs

diff --git a/core/src/fnc/mod.rs b/core/src/fnc/mod.rs
index 03143b95..e304a1fb 100644
--- a/core/src/fnc/mod.rs
+++ b/core/src/fnc/mod.rs
@@ -27,6 +27,7 @@ pub mod rand;
 pub mod script;
 pub mod search;
 pub mod session;
+pub mod shared;
 pub mod sleep;
 pub mod string;
 pub mod time;
@@ -700,6 +701,8 @@ pub async fn idiom(
 				"to_uuid" => r#type::uuid,
 				//
 				"repeat" => array::repeat,
+				//
+				"chain" => shared::chain((stk, ctx, opt, doc)).await,
 			)
 		}
 		v => v,
diff --git a/core/src/fnc/shared.rs b/core/src/fnc/shared.rs
new file mode 100644
index 00000000..c54320f7
--- /dev/null
+++ b/core/src/fnc/shared.rs
@@ -0,0 +1,16 @@
+use reblessive::tree::Stk;
+
+use crate::ctx::Context;
+use crate::dbs::Options;
+use crate::doc::CursorDoc;
+use crate::err::Error;
+use crate::sql::value::Value;
+use crate::sql::{Closure, Function};
+
+pub async fn chain(
+	(stk, ctx, opt, doc): (&mut Stk, &Context<'_>, &Options, Option<&CursorDoc<'_>>),
+	(value, worker): (Value, Closure),
+) -> Result<Value, Error> {
+	let fnc = Function::Anonymous(worker.into(), vec![value]);
+	fnc.compute(stk, ctx, opt, doc).await
+}
diff --git a/lib/tests/function.rs b/lib/tests/function.rs
index 9aa4bd11..0921cc9f 100644
--- a/lib/tests/function.rs
+++ b/lib/tests/function.rs
@@ -6349,6 +6349,7 @@ async fn function_idiom_chaining() -> Result<(), Error> {
 		// String is one of the types in the initial match statement,
 		// this test ensures that the dispatch macro does not exit early
 		"string".is_bool();
+		["1", "2"].join('').chain(|$v| <int> $v);
 	"#;
 	Test::new(sql)
 		.await?
@@ -6358,7 +6359,8 @@ async fn function_idiom_chaining() -> Result<(), Error> {
 		.expect_val("true")?
         .expect_error("There was a problem running the doesnt_exist() function. no such method found for the bool type")?
 	    .expect_val("true")?
-		.expect_val("false")?;
+		.expect_val("false")?
+        .expect_val("12")?;
 	Ok(())
 }