use CappedString and CowCappedString in generated unscribe fn

enumscribe/src/internal/capped_string.rs

@@ -21,6 +21,37 @@ impl<'a, const N: usize> CowCappedString<'a, N> {
             CowCappedString::Owned(s) => s,
         }
     }
+
+    /// Returns a new `CappedString` with capacity `M` containing the string converted to
+    /// uppercase. Returns `None` if the uppercase-converted string is longer than `M` bytes.
+    #[inline]
+    #[must_use]
+    pub fn to_uppercase<const M: usize>(&self) -> Option<CappedString<M>> {
+        CappedString::<M>::uppercase_from_str(self)
+    }
+}
+
+impl<'a, const N: usize> Deref for CowCappedString<'a, N> {
+    type Target = str;
+
+    #[inline]
+    fn deref(&self) -> &Self::Target {
+        self.as_str()
+    }
+}
+
+impl<'a, const N: usize> AsRef<str> for CowCappedString<'a, N> {
+    #[inline]
+    fn as_ref(&self) -> &str {
+        self
+    }
+}
+
+impl<'a, const N: usize> Borrow<str> for CowCappedString<'a, N> {
+    #[inline]
+    fn borrow(&self) -> &str {
+        self
+    }
 }
 
 #[cfg(feature = "serde")]
@@ -86,16 +117,45 @@ pub struct CappedString<const N: usize> {
 }
 
 impl<const N: usize> CappedString<N> {
-    /// Returns a new `CappedString` containing a copy of the given string data. Returns an error
-    /// if the string data is larger than `N` bytes.
+    /// Returns a new `CappedString` containing a copy of the given string data. Returns `None` if
+    /// the string data is larger than `N` bytes.
     #[inline]
     #[must_use]
     pub fn from_str(s: &str) -> Option<Self> {
         unsafe { Self::from_utf8_unchecked(s.as_bytes()) }
     }
 
+    /// Returns a new `CappedString` containing an uppercase conversion of the given string data.
+    /// Returns `None` if the converted string is larger than `N` bytes.
+    #[inline]
+    #[must_use]
+    pub fn uppercase_from_str(s: &str) -> Option<Self> {
+        let mut buf = [0u8; N];
+        let mut cursor = 0usize;
+
+        for c_orig in s.chars() {
+            for c_upper in c_orig.to_uppercase() {
+                let encode_buf = cursor
+                    .checked_add(c_upper.len_utf8())
+                    .and_then(|encode_buf_end| buf.get_mut(cursor..encode_buf_end))?;
+
+                // FIXME: avoid the panic asm that gets generated for this encode (can never panic,
+                // as we always have at least `c_upper.len_utf8()` buffer space).
+                let encoded = c_upper.encode_utf8(encode_buf);
+                cursor = cursor.checked_add(encoded.len())?;
+            }
+        }
+
+        let filled_buf = buf.get(..cursor)?;
+
+        // SAFETY:
+        // `filled_buf` has been filled with a sequence of bytes obtained from `char::encode_utf8`,
+        // so it is valid UTF-8.
+        unsafe { Self::from_utf8_unchecked(filled_buf) }
+    }
+
     /// Returns a new `CappedString` containing a copy of the given UTF-8 encoded string data.
-    /// Returns an error if more than `N` bytes of data are given.
+    /// Returns `None` if more than `N` bytes of data are given.
     /// 
     /// # Safety
     /// - `bs` must be valid UTF-8.
@@ -146,32 +206,11 @@ impl<const N: usize> CappedString<N> {
     }
 
     /// Returns a new `CappedString` with capacity `M` containing the string converted to
-    /// uppercase. Returns an error if the uppercase-converted string is longer than `M` bytes.
+    /// uppercase. Returns `None` if the uppercase-converted string is longer than `M` bytes.
     #[inline]
     #[must_use]
     pub fn to_uppercase<const M: usize>(&self) -> Option<CappedString<M>> {
-        let mut buf = [0u8; M];
-        let mut cursor = 0usize;
-
-        for c_orig in self.as_str().chars() {
-            for c_upper in c_orig.to_uppercase() {
-                let encode_buf = cursor
-                    .checked_add(c_upper.len_utf8())
-                    .and_then(|encode_buf_end| buf.get_mut(cursor..encode_buf_end))?;
-
-                // FIXME: avoid the panic asm that gets generated for this encode (can never panic,
-                // as we always have at least `c_upper.len_utf8()` buffer space).
-                let encoded = c_upper.encode_utf8(encode_buf);
-                cursor = cursor.checked_add(encoded.len())?;
-            }
-        }
-
-        let filled_buf = buf.get(..cursor)?;
-
-        // SAFETY:
-        // `filled_buf` has been filled with a sequence of bytes obtained from `char::encode_utf8`,
-        // so it is valid UTF-8.
-        unsafe { CappedString::from_utf8_unchecked(filled_buf) }
+        CappedString::<M>::uppercase_from_str(self)
     }
 }
 

enumscribe_derive/src/enums.rs

@@ -12,7 +12,45 @@ use crate::{CASE_INSENSITIVE, CRATE_ATTR, IGNORE, NAME, OTHER};
 
 #[derive(Clone)]
 pub(crate) struct Enum<'a> {
-    pub(crate) variants: Vec<Variant<'a>>,
+    variants: Box<[Variant<'a>]>,
+    name_capacity: usize,
+    name_upper_capacity: usize,
+}
+
+impl<'a> Enum<'a> {
+    pub(crate) fn new(variants: Box<[Variant<'a>]>) -> Self {
+        let name_capacity = variants
+            .iter()
+            .filter_map(|v| v.v_type.as_named())
+            .map(|named| named.name().len())
+            .max()
+            .unwrap_or(0);
+
+        let name_upper_capacity = variants
+            .iter()
+            .filter_map(|v| v.v_type.as_named())
+            .map(|named| named.name_upper().len())
+            .max()
+            .unwrap_or(0);
+
+        Self {
+            variants,
+            name_capacity,
+            name_upper_capacity,
+        }
+    }
+
+    pub(crate) fn variants(&self) -> &[Variant<'a>] {
+        &self.variants
+    }
+
+    pub(crate) fn name_capacity(&self) -> usize {
+        self.name_capacity
+    }
+
+    pub(crate) fn name_upper_capacity(&self) -> usize {
+        self.name_upper_capacity
+    }
 }
 
 #[derive(Clone)]
@@ -25,14 +63,69 @@ pub(crate) struct Variant<'a> {
 #[derive(Clone)]
 pub(crate) enum VariantType<'a> {
     Ignore,
-    Named {
-        name: String,
+    Named(NamedVariant),
+    Other(OtherVariant<'a>),
+}
+
+impl<'a> VariantType<'a> {
+    pub(crate) fn as_named(&self) -> Option<&NamedVariant> {
+        match self {
+            Self::Named(named) => Some(named),
+            _ => None,
+        }
+    }
+}
+
+#[derive(Clone)]
+pub(crate) struct NamedVariant {
+    name: Box<str>,
+    name_upper: Box<str>,
+    constructor: VariantConstructor,
+    case_insensitive: bool,
+}
+
+impl NamedVariant {
+    pub(crate) fn new(
+        name: Box<str>,
         constructor: VariantConstructor,
-        case_insensitive: bool,
-    },
-    Other {
-        field_name: Option<&'a Ident>,
-    },
+        case_insensitive: bool
+    ) -> Self
+    {
+        let name_upper = char_wise_uppercase(&name);
+        Self {
+            name,
+            name_upper,
+            constructor,
+            case_insensitive,
+        }
+    }
+    
+    pub(crate) fn name(&self) -> &str {
+        &self.name
+    }
+
+    pub(crate) fn name_upper(&self) -> &str {
+        &self.name_upper
+    }
+
+    pub(crate) fn constructor(&self) -> VariantConstructor {
+        self.constructor   
+    }
+
+    pub(crate) fn case_insensitive(&self) -> bool {
+        self.case_insensitive
+    }
+}
+
+#[derive(Clone)]
+pub(crate) struct OtherVariant<'a> {
+    field_name: Option<&'a Ident>,
+}
+
+impl<'a> OtherVariant<'a> {
+    pub(crate) fn field_name(&self) -> Option<&'a Ident> {
+        self.field_name
+    }
 }
 
 #[derive(Clone, Copy, Debug)]
@@ -58,20 +151,18 @@ impl<'a> Variant<'a> {
         match &self.v_type {
             VariantType::Ignore => Ok(None),
 
-            VariantType::Named {
-                name, constructor, ..
-            } => {
-                let constructor_tokens = constructor.empty();
+            VariantType::Named(named) => {
+                let constructor_tokens = named.constructor().empty_toks();
                 let pattern = quote! { #enum_ident::#variant_ident #constructor_tokens };
-                Ok(Some((pattern, named_fn(self, enum_ident, name)?)))
+                Ok(Some((pattern, named_fn(self, enum_ident, named.name())?)))
             }
 
-            VariantType::Other { field_name } => {
-                let field_name_tokens = match field_name {
+            VariantType::Other(other) => {
+                let field_name_tokens = match other.field_name() {
                     Some(field_name) => field_name.to_token_stream(),
                     None => quote! { __enumscribe_other_inner },
                 };
-                let pattern = match field_name {
+                let pattern = match other.field_name() {
                     Some(_) => quote! { #enum_ident::#variant_ident{#field_name_tokens} },
                     None => quote! { #enum_ident::#variant_ident(#field_name_tokens) },
                 };
@@ -85,7 +176,7 @@ impl<'a> Variant<'a> {
 }
 
 impl VariantConstructor {
-    pub(crate) fn empty(&self) -> TokenStream2 {
+    pub(crate) fn empty_toks(&self) -> TokenStream2 {
         match self {
             VariantConstructor::None => quote! {},
             VariantConstructor::Paren => quote! { () },
@@ -220,7 +311,7 @@ pub(crate) fn parse_enum<'a>(data: &'a DataEnum, attrs: &'a [Attribute]) -> Macr
 
             Variant {
                 data: variant,
-                v_type: VariantType::Other { field_name },
+                v_type: VariantType::Other(OtherVariant { field_name }),
                 span: variant_span,
             }
         } else {
@@ -279,13 +370,12 @@ pub(crate) fn parse_enum<'a>(data: &'a DataEnum, attrs: &'a [Attribute]) -> Macr
                 Fields::Unit => VariantConstructor::None,
             };
 
+            let named = NamedVariant::new(name.into_boxed_str(), constructor, case_insensitive);
+            let v_type = VariantType::Named(named);
+
             Variant {
                 data: variant,
-                v_type: VariantType::Named {
-                    name,
-                    constructor,
-                    case_insensitive,
-                },
+                v_type,
                 span: variant_span,
             }
         };
@@ -293,5 +383,13 @@ pub(crate) fn parse_enum<'a>(data: &'a DataEnum, attrs: &'a [Attribute]) -> Macr
         variants.push(scribe_variant);
     }
 
-    Ok(Enum { variants })
-}
+    Ok(Enum::new(variants.into_boxed_slice()))
+}
+
+fn char_wise_uppercase(s: &str) -> Box<str> {
+    // Use the same uppercase algorithm as `enumscribe::internal::capped_string`.
+    s.chars()
+        .flat_map(char::to_uppercase)
+        .collect::<String>()
+        .into_boxed_str()
+}

enumscribe_derive/src/lib.rs

@@ -59,9 +59,9 @@ where
 
     let enum_ident = &input.ident;
 
-    let mut match_arms = Vec::with_capacity(parsed_enum.variants.len());
+    let mut match_arms = Vec::with_capacity(parsed_enum.variants().len());
 
-    for variant in parsed_enum.variants.iter() {
+    for variant in parsed_enum.variants().iter() {
         match variant.match_variant(enum_ident, &named_fn, &other_fn) {
             Ok(Some((pattern, result))) => match_arms.push(quote! { #pattern => #result }),
             Ok(None) => return ignore_err_fn(variant, enum_ident).into(),
@@ -102,9 +102,9 @@ where
     let enum_ident = &input.ident;
 
     let mut ignore_variant = false;
-    let mut match_arms = Vec::with_capacity(parsed_enum.variants.len());
+    let mut match_arms = Vec::with_capacity(parsed_enum.variants().len());
 
-    for variant in parsed_enum.variants.iter() {
+    for variant in parsed_enum.variants().iter() {
         match variant.match_variant(enum_ident, &named_fn, &other_fn) {
             Ok(Some((pattern, result))) => match_arms.push(quote! { #pattern => #result }),
             Ok(None) => ignore_variant = true,
@@ -192,30 +192,28 @@ where
     let mut case_sensitive_arms = Vec::new();
     let mut case_insensitive_arms = Vec::new();
 
-    for variant in parsed_enum.variants.iter() {
+    for variant in parsed_enum.variants().iter() {
         let variant_ident = &variant.data.ident;
 
         match &variant.v_type {
             VariantType::Ignore => (),
 
-            VariantType::Named {
-                name,
-                constructor,
-                case_insensitive,
-            } => {
-                let match_pattern = if *case_insensitive {
-                    let lowercase_name = name.to_lowercase();
-                    quote! { #lowercase_name }
+            VariantType::Named(named) => {
+                let match_pattern = if named.case_insensitive() {
+                    let uppercase_name = named.name_upper();
+                    quote! { #uppercase_name }
                 } else {
+                    let name = named.name();
                     quote! { #name }
                 };
 
-                let constructor_tokens = constructor.empty();
-                let constructed_variant =
-                    quote! { #enum_ident::#variant_ident #constructor_tokens };
+                let constructor_tokens = named.constructor().empty_toks();
+                let constructed_variant = quote! {
+                    #enum_ident::#variant_ident #constructor_tokens
+                };
                 let match_result = named_fn(constructed_variant);
 
-                if *case_insensitive {
+                if named.case_insensitive() {
                     &mut case_insensitive_arms
                 } else {
                     &mut case_sensitive_arms
@@ -223,11 +221,11 @@ where
                 .push(quote! { #match_pattern => #match_result });
             }
 
-            VariantType::Other { field_name } => {
+            VariantType::Other(other) => {
                 let unscribe_value =
                     quote! { <_ as ::std::convert::Into<_>>::into(#match_against) };
 
-                let constructed_variant = match field_name {
+                let constructed_variant = match other.field_name() {
                     None => quote! {
                         #enum_ident::#variant_ident(#unscribe_value)
                     },
@@ -251,10 +249,23 @@ where
     let case_insensitive_match = if case_insensitive_arms.is_empty() {
         None
     } else {
+        let match_against_upper_ident = quote! { __enumscribe_unscribe_uppercase };
+        let name_upper_cap = parsed_enum.name_upper_capacity();
+
         Some(quote! {
-            let __enumscribe_unscribe_lowercase = #match_against.to_lowercase();
-            match __enumscribe_unscribe_lowercase.as_str() {
-                #(#case_insensitive_arms,)*
+            match ::enumscribe
+                ::internal
+                ::capped_string
+                ::CappedString
+                ::<#name_upper_cap>
+                ::uppercase_from_str(#match_against)
+            {
+                Some(#match_against_upper_ident) => {
+                    match &*#match_against_upper_ident {
+                        #(#case_insensitive_arms,)*
+                        #other_arm,
+                    }
+                },
                 #other_arm,
             }
         })
@@ -659,23 +670,22 @@ pub fn derive_enum_serialize(input: TokenStream) -> TokenStream {
     let mut match_arms = Vec::new();
     let mut ignore_variant = false;
 
-    for variant in parsed_enum.variants.iter() {
+    for variant in parsed_enum.variants().iter() {
         let variant_ident = &variant.data.ident;
 
         match &variant.v_type {
             VariantType::Ignore => ignore_variant = true,
 
-            VariantType::Named {
-                name, constructor, ..
-            } => {
-                let constructor_tokens = constructor.empty();
+            VariantType::Named(named) => {
+                let constructor_tokens = named.constructor().empty_toks();
+                let name = named.name();
                 match_arms.push(quote! {
                     #enum_ident::#variant_ident #constructor_tokens =>
                         #serializer_ident.serialize_str(#name)
                 })
             }
 
-            VariantType::Other { field_name } => match field_name {
+            VariantType::Other(other) => match other.field_name() {
                 Some(field_name) => match_arms.push(quote! {
                     #enum_ident::#variant_ident { #field_name } =>
                         #serializer_ident.serialize_str(&#field_name)
@@ -748,13 +758,14 @@ pub fn derive_enum_deserialize(input: TokenStream) -> TokenStream {
     let enum_ident = &input.ident;
 
     let deserializer_ident = quote! { __enumscribe_deserializer };
+    let deserialized_cow_capped_str_ident = quote! { __enumscribe_deserialized_cow_capped_str };
     let deserialized_str_ident = quote! { __enumscribe_deserialized_str };
 
     let variant_strings = parsed_enum
-        .variants
+        .variants()
         .iter()
         .map(|variant| match &variant.v_type {
-            VariantType::Named { name, .. } => Some(name.as_str()),
+            VariantType::Named(named) => Some(named.name()),
             _ => None,
         })
         .filter_map(|name| name)
@@ -780,13 +791,23 @@ pub fn derive_enum_deserialize(input: TokenStream) -> TokenStream {
         }),
     ));
 
+    let name_cap = parsed_enum.name_capacity();
+
     (quote! {
         #[automatically_derived]
         impl<'de> ::serde::Deserialize<'de> for #enum_ident {
             fn deserialize<D>(#deserializer_ident: D) -> ::core::result::Result<Self, D::Error>
                 where D: ::serde::Deserializer<'de>
             {
-                let #deserialized_str_ident = <&str as ::serde::Deserialize<'_>>::deserialize(#deserializer_ident)?;
+                let #deserialized_cow_capped_str_ident = <
+                    ::enumscribe
+                        ::internal
+                        ::capped_string
+                        ::CowCappedString<'de, #name_cap>
+                    as ::serde::Deserialize<'_>
+                >::deserialize(#deserializer_ident)?;
+
+                let #deserialized_str_ident = &*#deserialized_cow_capped_str_ident;
                 #main_match
             }
         }