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use crate::Error;
use quote::quote;
pub fn generate(error: Error) -> proc_macro2::TokenStream {
let error_enum = &error.raw_enum;
let enum_name = &error.ident;
let variant_dispatch: Vec<proc_macro2::TokenStream> = error
.raw_enum
.variants
.iter()
.enumerate()
.map(|(idx, variant)| {
let ident = &variant.ident;
let error_code = &error.codes[idx];
let msg = match &error_code.msg {
None => {
quote! {
<Self as std::fmt::Debug>::fmt(self, fmt)
}
}
Some(msg) => {
quote! {
write!(fmt, #msg)
}
}
};
quote! {
#enum_name::#ident => #msg
}
})
.collect();
quote! {
pub type Result<T> = std::result::Result<T, Error>;
#[derive(thiserror::Error, Debug)]
pub enum Error {
#[error(transparent)]
ProgramError(#[from] ProgramError),
#[error(transparent)]
ErrorCode(#[from] #enum_name),
}
#[derive(Debug, Clone, Copy)]
#[repr(u32)]
#error_enum
impl std::fmt::Display for #enum_name {
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::result::Result<(), std::fmt::Error> {
match self {
#(#variant_dispatch),*
}
}
}
impl std::error::Error for #enum_name {}
impl std::convert::From<Error> for ProgramError {
fn from(e: Error) -> ProgramError {
let error_offset = 100u32;
match e {
Error::ProgramError(e) => e,
Error::ErrorCode(c) => ProgramError::Custom(c as u32 + error_offset),
}
}
}
impl std::convert::From<#enum_name> for ProgramError {
fn from(e: #enum_name) -> ProgramError {
let err: Error = e.into();
err.into()
}
}
}
}