diff options
Diffstat (limited to 'bzipper_macros/src/impls/sized_encode_enum.rs')
| -rw-r--r-- | bzipper_macros/src/impls/sized_encode_enum.rs | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/bzipper_macros/src/impls/sized_encode_enum.rs b/bzipper_macros/src/impls/sized_encode_enum.rs new file mode 100644 index 0000000..3bfc961 --- /dev/null +++ b/bzipper_macros/src/impls/sized_encode_enum.rs @@ -0,0 +1,54 @@ +// Copyright 2024 Gabriel Bjørnager Jensen. +// +// This file is part of bZipper. +// +// bZipper is free software: you can redistribute +// it and/or modify it under the terms of the GNU +// Lesser General Public License as published by +// the Free Software Foundation, either version 3 +// of the License, or (at your option) any later +// version. +// +// bZipper is distributed in the hope that it will +// be useful, but WITHOUT ANY WARRANTY; without +// even the implied warranty of MERCHANTABILITY or +// FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +// You should have received a copy of the GNU Less- +// er General Public License along with bZipper. If +// not, see <https://www.gnu.org/licenses/>. + +use proc_macro2::TokenStream; +use quote::quote; +use syn::DataEnum; + +#[must_use] +pub fn sized_encode_enum(data: &DataEnum) -> TokenStream { + let mut sizes = Vec::new(); + + // Iterate over each variant and give it a unique + // encoding scheme. + for variant in &data.variants { + let mut field_tys = Vec::new(); + + for field in &variant.fields { + field_tys.push(&field.ty); + } + + sizes.push(quote! { + <isize as ::bzipper::SizedEncode>::MAX_ENCODED_SIZE + #(+ <#field_tys as ::bzipper::SizedEncode>::MAX_ENCODED_SIZE)* + }); + } + + quote! { + const MAX_ENCODED_SIZE: usize = const { + let mut max_encoded_size = 0x0usize; + + #(if #sizes > max_encoded_size { max_encoded_size = #sizes };)* + + max_encoded_size + }; + } +} |