From 499b34cee0ea75a9a7e6b267c0328c166bc7ed57 Mon Sep 17 00:00:00 2001
From: Jeong YunWon <jeong@youknowone.org>
Date: Thu, 10 Nov 2022 15:39:31 +0900
Subject: [PATCH] Apply let-else statements

---
 compiler/codegen/src/compile.rs | 4 +---
 compiler/parser/build.rs        | 8 ++------
 stdlib/src/scproxy.rs           | 8 ++------
 vm/src/builtins/function.rs     | 7 +++----
 vm/src/builtins/type.rs         | 4 +---
 vm/src/dictdatatype.rs          | 4 +---
 vm/src/protocol/number.rs       | 4 +---
 vm/src/stdlib/itertools.rs      | 4 +---
 8 files changed, 12 insertions(+), 31 deletions(-)

diff --git a/compiler/codegen/src/compile.rs b/compiler/codegen/src/compile.rs
index 6666d2314..7bf616923 100644
--- a/compiler/codegen/src/compile.rs
+++ b/compiler/codegen/src/compile.rs
@@ -1412,9 +1412,7 @@ impl Compiler {
     ) -> CompileResult<()> {
         let with_location = self.current_source_location;
 
-        let (item, items) = if let Some(parts) = items.split_first() {
-            parts
-        } else {
+        let Some((item, items)) = items.split_first() else {
             return Err(self.error(CodegenErrorType::EmptyWithItems));
         };
 
diff --git a/compiler/parser/build.rs b/compiler/parser/build.rs
index 81c28f43b..4559f2630 100644
--- a/compiler/parser/build.rs
+++ b/compiler/parser/build.rs
@@ -17,9 +17,7 @@ fn main() -> anyhow::Result<()> {
 }
 
 fn requires_lalrpop(source: &str, target: &str) -> Option<String> {
-    let target = if let Ok(target) = File::open(target) {
-        target
-    } else {
+    let Ok(target) = File::open(target) else {
         return Some("python.rs doesn't exist. regenerate.".to_owned());
     };
 
@@ -71,9 +69,7 @@ fn requires_lalrpop(source: &str, target: &str) -> Option<String> {
 }
 
 fn try_lalrpop(source: &str, target: &str) -> anyhow::Result<()> {
-    let _message = if let Some(msg) = requires_lalrpop(source, target) {
-        msg
-    } else {
+    let Some(_message) = requires_lalrpop(source, target) else {
         return Ok(());
     };
 
diff --git a/stdlib/src/scproxy.rs b/stdlib/src/scproxy.rs
index e1e0fce73..a9f1c1447 100644
--- a/stdlib/src/scproxy.rs
+++ b/stdlib/src/scproxy.rs
@@ -33,9 +33,7 @@ mod _scproxy {
 
     #[pyfunction]
     fn _get_proxy_settings(vm: &VirtualMachine) -> PyResult<Option<PyDictRef>> {
-        let proxy_dict = if let Some(p) = proxy_dict() {
-            p
-        } else {
+        let Some(proxy_dict) = proxy_dict() else {
             return Ok(None);
         };
 
@@ -73,9 +71,7 @@ mod _scproxy {
 
     #[pyfunction]
     fn _get_proxies(vm: &VirtualMachine) -> PyResult<Option<PyDictRef>> {
-        let proxy_dict = if let Some(p) = proxy_dict() {
-            p
-        } else {
+        let Some(proxy_dict) = proxy_dict() else {
             return Ok(None);
         };
 
diff --git a/vm/src/builtins/function.rs b/vm/src/builtins/function.rs
index 1a3cc2bf0..b23b0c8fe 100644
--- a/vm/src/builtins/function.rs
+++ b/vm/src/builtins/function.rs
@@ -392,13 +392,12 @@ impl PyFunction {
     fn set_qualname(&self, value: PySetterValue, vm: &VirtualMachine) -> PyResult<()> {
         match value {
             PySetterValue::Assign(value) => {
-                if let Ok(qualname) = value.downcast::<PyStr>() {
-                    *self.qualname.lock() = qualname;
-                } else {
+                let Ok(qualname) = value.downcast::<PyStr>() else {
                     return Err(vm.new_type_error(
                         "__qualname__ must be set to a string object".to_string(),
                     ));
-                }
+                };
+                *self.qualname.lock() = qualname;
             }
             PySetterValue::Delete => {
                 return Err(
diff --git a/vm/src/builtins/type.rs b/vm/src/builtins/type.rs
index 020add198..a4db53225 100644
--- a/vm/src/builtins/type.rs
+++ b/vm/src/builtins/type.rs
@@ -959,9 +959,7 @@ impl GetAttr for PyType {
             ))
         }
 
-        let name = if let Some(name) = vm.ctx.interned_str(&*name_str) {
-            name
-        } else {
+        let Some(name) = vm.ctx.interned_str(&*name_str) else {
             return Err(attribute_error(zelf, name_str.as_str(), vm));
         };
         vm_trace!("type.__getattribute__({:?}, {:?})", zelf, name);
diff --git a/vm/src/dictdatatype.rs b/vm/src/dictdatatype.rs
index 2746c90e1..1114fa1ed 100644
--- a/vm/src/dictdatatype.rs
+++ b/vm/src/dictdatatype.rs
@@ -586,9 +586,7 @@ impl<T: Clone> Dict<T> {
         pred: impl Fn(&T) -> Result<bool, E>,
     ) -> Result<PopInnerResult<T>, E> {
         let (entry_index, index_index) = lookup;
-        let entry_index = if let Some(entry_index) = entry_index.index() {
-            entry_index
-        } else {
+        let Some(entry_index) = entry_index.index() else {
             return Ok(ControlFlow::Break(None));
         };
         let inner = &mut *self.write();
diff --git a/vm/src/protocol/number.rs b/vm/src/protocol/number.rs
index da144dfae..88645c1d9 100644
--- a/vm/src/protocol/number.rs
+++ b/vm/src/protocol/number.rs
@@ -243,9 +243,7 @@ impl PyNumber<'_> {
 
     // PyNumber_Check
     pub fn check(obj: &PyObject) -> bool {
-        let methods = if let Some(m) = Self::find_methods(obj) {
-            m
-        } else {
+        let Some(methods) = Self::find_methods(obj) else {
             return false;
         };
         let methods = methods.as_ref();
diff --git a/vm/src/stdlib/itertools.rs b/vm/src/stdlib/itertools.rs
index 09a3f2634..ad41bdc87 100644
--- a/vm/src/stdlib/itertools.rs
+++ b/vm/src/stdlib/itertools.rs
@@ -110,9 +110,7 @@ mod decl {
     impl IterNextIterable for PyItertoolsChain {}
     impl IterNext for PyItertoolsChain {
         fn next(zelf: &Py<Self>, vm: &VirtualMachine) -> PyResult<PyIterReturn> {
-            let source = if let Some(source) = zelf.source.read().clone() {
-                source
-            } else {
+            let Some(source) = zelf.source.read().clone() else {
                 return Ok(PyIterReturn::StopIteration(None));
             };
             let next = loop {