From 7d58d8236145478fb9f996e1990d61515c14d0b6 Mon Sep 17 00:00:00 2001
From: Maximilian Roos <m@maxroos.com>
Date: Thu, 29 Feb 2024 18:25:38 -0800
Subject: [PATCH] internal: Refine rust prql code

This makes the rust code a bit more idiomatic. It builds on top of #60616, which can merge first. There aren't any rust tests here, so would like to check CI.
---
 rust/prql/src/lib.rs | 29 +++++++++++++----------------
 1 file changed, 13 insertions(+), 16 deletions(-)

diff --git a/rust/prql/src/lib.rs b/rust/prql/src/lib.rs
index 621f6aae5a2..9e4b0ae194a 100644
--- a/rust/prql/src/lib.rs
+++ b/rust/prql/src/lib.rs
@@ -14,39 +14,36 @@ fn set_output(result: String, out: *mut *mut u8, out_size: *mut u64) {
     *out_ptr = CString::new(result).unwrap().into_raw() as *mut u8;
 }
 
+/// Converts a PRQL query from a raw C string to SQL, returning an error code if the conversion fails.
 pub unsafe extern "C" fn prql_to_sql_impl(
     query: *const u8,
     size: u64,
     out: *mut *mut u8,
     out_size: *mut u64,
 ) -> i64 {
-    let query_vec = unsafe { slice::from_raw_parts(query, size.try_into().unwrap()) }.to_vec();
-    let maybe_prql_query = String::from_utf8(query_vec);
-    if maybe_prql_query.is_err() {
+    let query_vec = slice::from_raw_parts(query, size.try_into().unwrap()).to_vec();
+    let Ok(query_str) = String::from_utf8(query_vec) else {
         set_output(
-            String::from("The PRQL query must be UTF-8 encoded!"),
+            "The PRQL query must be UTF-8 encoded!".to_string(),
             out,
             out_size,
         );
         return 1;
-    }
-    let prql_query = maybe_prql_query.unwrap();
-    let opts = &Options {
+    };
+
+    let opts = Options {
         format: true,
         target: Target::Sql(Some(Dialect::ClickHouse)),
         signature_comment: false,
         color: false,
     };
-    let (is_err, res) = match prqlc::compile(&prql_query, &opts) {
-        Ok(sql_str) => (false, sql_str),
-        Err(err) => (true, err.to_string()),
-    };
 
-    set_output(res, out, out_size);
-
-    match is_err {
-        true => 1,
-        false => 0,
+    if let Ok(sql_str) = prqlc::compile(&query_str, &opts) {
+        set_output(sql_str, out, out_size);
+        0
+    } else {
+        set_output("PRQL compilation failed!".to_string(), out, out_size);
+        1
     }
 }