Merge pull request RustPython#4567 from youknowone/unicodedata

clean up unicodedata

Author: youknowone

stdlib/src/unicodedata.rs

@@ -1,7 +1,10 @@
 /* Access to the unicode database.
    See also: https://docs.python.org/3/library/unicodedata.html
 */
-use crate::vm::{PyObjectRef, PyPayload, VirtualMachine};
+use crate::vm::{
+    builtins::PyStr, convert::TryFromBorrowedObject, PyObject, PyObjectRef, PyPayload, PyResult,
+    VirtualMachine,
+};
 
 pub fn make_module(vm: &VirtualMachine) -> PyObjectRef {
     let module = unicodedata::make_module(vm);
@@ -28,6 +31,30 @@ pub fn make_module(vm: &VirtualMachine) -> PyObjectRef {
     module
 }
 
+enum NormalizeForm {
+    Nfc,
+    Nfkc,
+    Nfd,
+    Nfkd,
+}
+
+impl TryFromBorrowedObject for NormalizeForm {
+    fn try_from_borrowed_object(vm: &VirtualMachine, obj: &PyObject) -> PyResult<Self> {
+        obj.try_value_with(
+            |form: &PyStr| {
+                Ok(match form.as_str() {
+                    "NFC" => NormalizeForm::Nfc,
+                    "NFKC" => NormalizeForm::Nfkc,
+                    "NFD" => NormalizeForm::Nfd,
+                    "NFKD" => NormalizeForm::Nfkd,
+                    _ => return Err(vm.new_value_error("invalid normalization form".to_owned())),
+                })
+            },
+            vm,
+        )
+    }
+}
+
 #[pymodule]
 mod unicodedata {
     use crate::vm::{
@@ -63,11 +90,7 @@ mod unicodedata {
                 vm.new_type_error("argument must be an unicode character, not str".to_owned())
             })?;
 
-            if self.check_age(c) {
-                Ok(Some(c))
-            } else {
-                Ok(None)
-            }
+            Ok(self.check_age(c).then_some(c))
         }
     }
 
@@ -112,40 +135,41 @@ mod unicodedata {
         }
 
         #[pymethod]
-        fn bidirectional(&self, character: PyStrRef, vm: &VirtualMachine) -> PyResult<String> {
+        fn bidirectional(
+            &self,
+            character: PyStrRef,
+            vm: &VirtualMachine,
+        ) -> PyResult<&'static str> {
             let bidi = match self.extract_char(character, vm)? {
                 Some(c) => BidiClass::of(c).abbr_name(),
                 None => "",
             };
-            Ok(bidi.to_owned())
+            Ok(bidi)
         }
 
         /// NOTE: This function uses 9.0.0 database instead of 3.2.0
         #[pymethod]
-        fn east_asian_width(&self, character: PyStrRef, vm: &VirtualMachine) -> PyResult<String> {
+        fn east_asian_width(
+            &self,
+            character: PyStrRef,
+            vm: &VirtualMachine,
+        ) -> PyResult<&'static str> {
             Ok(self
                 .extract_char(character, vm)?
                 .map_or(EastAsianWidth::Neutral, |c| c.east_asian_width())
-                .abbr_name()
-                .to_owned())
+                .abbr_name())
         }
 
         #[pymethod]
-        fn normalize(
-            &self,
-            form: PyStrRef,
-            unistr: PyStrRef,
-            vm: &VirtualMachine,
-        ) -> PyResult<String> {
+        fn normalize(&self, form: super::NormalizeForm, unistr: PyStrRef) -> PyResult<String> {
+            use super::NormalizeForm::*;
             let text = unistr.as_str();
-            let normalized_text = match form.as_str() {
-                "NFC" => text.nfc().collect::<String>(),
-                "NFKC" => text.nfkc().collect::<String>(),
-                "NFD" => text.nfd().collect::<String>(),
-                "NFKD" => text.nfkd().collect::<String>(),
-                _ => return Err(vm.new_value_error("invalid normalization form".to_owned())),
+            let normalized_text = match form {
+                Nfc => text.nfc().collect::<String>(),
+                Nfkc => text.nfkc().collect::<String>(),
+                Nfd => text.nfd().collect::<String>(),
+                Nfkd => text.nfkd().collect::<String>(),
             };
-
             Ok(normalized_text)
         }