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use std::fmt::Write;
use std::str::FromStr;
use super::super::TraitHandler;
use super::models::{FieldAttribute, FieldAttributeBuilder, TypeAttributeBuilder};
use crate::Trait;
use proc_macro2::TokenStream;
use quote::quote;
use syn::{punctuated::Punctuated, Data, DeriveInput, Fields, Generics, Meta};
pub struct CloneEnumHandler;
impl TraitHandler for CloneEnumHandler {
fn trait_meta_handler(
ast: &DeriveInput,
tokens: &mut TokenStream,
traits: &[Trait],
meta: &Meta,
) {
let type_attribute = TypeAttributeBuilder {
enable_flag: true,
enable_bound: true,
}
.from_clone_meta(meta);
let mut bound = Punctuated::new();
let mut clone_tokens = TokenStream::new();
let mut clone_from_tokens = TokenStream::new();
if let Data::Enum(data) = &ast.data {
let mut variant_idents = Vec::new();
let mut field_attributes_names: Vec<(bool, Vec<FieldAttribute>, Vec<String>)> =
Vec::new();
#[cfg(feature = "Copy")]
let mut has_custom_clone_method = false;
for variant in data.variants.iter() {
let _ = TypeAttributeBuilder {
enable_flag: false,
enable_bound: false,
}
.from_attributes(&variant.attrs, traits);
let mut field_attributes = Vec::new();
let mut field_names = Vec::new();
let mut is_tuple = true;
match &variant.fields {
Fields::Unit => (),
Fields::Named(fields) => {
is_tuple = false;
for field in fields.named.iter() {
let field_attribute = FieldAttributeBuilder {
enable_impl: true,
}
.from_attributes(&field.attrs, traits);
let field_name = field.ident.as_ref().unwrap().to_string();
#[cfg(feature = "Copy")]
if field_attribute.clone_method.is_some() {
has_custom_clone_method = true;
}
field_attributes.push(field_attribute);
field_names.push(field_name);
}
}
Fields::Unnamed(fields) => {
for (index, field) in fields.unnamed.iter().enumerate() {
let field_attribute = FieldAttributeBuilder {
enable_impl: true,
}
.from_attributes(&field.attrs, traits);
let field_name = format!("_{}", index);
#[cfg(feature = "Copy")]
if field_attribute.clone_method.is_some() {
has_custom_clone_method = true;
}
field_attributes.push(field_attribute);
field_names.push(field_name);
}
}
}
variant_idents.push(variant.ident.to_string());
field_attributes_names.push((is_tuple, field_attributes, field_names));
}
let enum_name = ast.ident.to_string();
#[cfg(feature = "Copy")]
let contains_copy = !has_custom_clone_method && traits.contains(&Trait::Copy);
#[cfg(not(feature = "Copy"))]
let contains_copy = false;
if contains_copy {
bound = type_attribute
.bound
.into_punctuated_where_predicates_by_generic_parameters_with_copy(
&ast.generics.params,
);
clone_tokens.extend(quote!(*self));
let mut match_tokens = String::from("match self {");
for (index, variant_ident) in variant_idents.iter().enumerate() {
let field_attributes_names = &field_attributes_names[index];
let is_tuple = field_attributes_names.0;
let field_attributes = &field_attributes_names.1;
let field_names = &field_attributes_names.2;
let is_unit = field_names.is_empty();
if is_unit {
match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} => {{ if let {enum_name}::{variant_ident} = _source {{ done = true; }} }}", enum_name = enum_name, variant_ident = variant_ident)).unwrap();
} else {
let mut pattern_tokens = String::new();
let mut pattern_2_tokens = String::new();
if is_tuple {
for field_name in field_names {
pattern_tokens
.write_fmt(format_args!(
"{field_name},",
field_name = field_name
))
.unwrap();
pattern_2_tokens
.write_fmt(format_args!(
"___{field_name},",
field_name = field_name
))
.unwrap();
}
} else {
for field_name in field_names {
pattern_tokens
.write_fmt(format_args!(
"{field_name},",
field_name = field_name
))
.unwrap();
pattern_2_tokens
.write_fmt(format_args!(
"{field_name}: ___{field_name},",
field_name = field_name
))
.unwrap();
}
}
let mut block_tokens = String::new();
for (index, field_attribute) in field_attributes.iter().enumerate() {
let field_name = &field_names[index];
let clone_trait = &field_attribute.clone_trait;
let clone_method = &field_attribute.clone_method;
match clone_trait {
Some(clone_trait) => {
let clone_method = clone_method.as_ref().unwrap();
block_tokens.write_fmt(format_args!("*{field_name} = {clone_trait}::{clone_method}(___{field_name});", clone_trait = clone_trait, clone_method = clone_method, field_name = field_name)).unwrap();
}
None => {
match clone_method {
Some(clone_method) => {
block_tokens.write_fmt(format_args!("*{field_name} = {clone_method}(___{field_name});", clone_method = clone_method, field_name = field_name)).unwrap();
}
None => {
block_tokens.write_fmt(format_args!("core::clone::Clone::clone_from({field_name}, ___{field_name});", field_name = field_name)).unwrap();
}
}
}
}
}
if is_tuple {
match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} ( {pattern_tokens} ) => {{ if let {enum_name}::{variant_ident} ( {pattern_2_tokens} ) = _source {{ {block_tokens} done = true; }} }}", enum_name = enum_name, variant_ident = variant_ident, pattern_tokens = pattern_tokens, pattern_2_tokens = pattern_2_tokens, block_tokens = block_tokens)).unwrap();
} else {
match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} {{ {pattern_tokens} }} => {{ if let {enum_name}::{variant_ident} {{ {pattern_2_tokens} }} = _source {{ {block_tokens} }} done = true; }}", enum_name = enum_name, variant_ident = variant_ident, pattern_tokens = pattern_tokens, pattern_2_tokens = pattern_2_tokens, block_tokens = block_tokens)).unwrap();
}
}
}
match_tokens.push('}');
clone_from_tokens.extend(TokenStream::from_str(&match_tokens).unwrap());
} else {
bound = type_attribute
.bound
.into_punctuated_where_predicates_by_generic_parameters(&ast.generics.params);
let mut clone_match_tokens = String::from("match self {");
let mut clone_from_match_tokens = String::from("match self {");
for (index, variant_ident) in variant_idents.iter().enumerate() {
let field_attributes_names = &field_attributes_names[index];
let is_tuple = field_attributes_names.0;
let field_attributes = &field_attributes_names.1;
let field_names = &field_attributes_names.2;
let is_unit = field_names.is_empty();
if is_unit {
clone_match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} => {{ {enum_name}::{variant_ident} }}", enum_name = enum_name, variant_ident = variant_ident)).unwrap();
clone_from_match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} => {{ if let {enum_name}::{variant_ident} = _source {{ done = true; }} }}", enum_name = enum_name, variant_ident = variant_ident)).unwrap();
} else {
let mut pattern_tokens = String::new();
let mut pattern_2_tokens = String::new();
let mut pattern_3_tokens = String::new();
if is_tuple {
let mut clone = format!(
"{enum_name}::{variant_ident}(",
enum_name = enum_name,
variant_ident = variant_ident
);
let mut clone_from = String::new();
for field_name in field_names {
pattern_tokens
.write_fmt(format_args!(
"{field_name},",
field_name = field_name
))
.unwrap();
pattern_2_tokens
.write_fmt(format_args!(
"{field_name},",
field_name = field_name
))
.unwrap();
pattern_3_tokens
.write_fmt(format_args!(
"___{field_name},",
field_name = field_name
))
.unwrap();
}
for (index, field_attribute) in field_attributes.iter().enumerate() {
let field_name = &field_names[index];
let clone_trait = &field_attribute.clone_trait;
let clone_method = &field_attribute.clone_method;
match clone_trait {
Some(clone_trait) => {
let clone_method = clone_method.as_ref().unwrap();
clone
.write_fmt(format_args!(
"{clone_trait}::{clone_method}({field_name}),",
clone_trait = clone_trait,
clone_method = clone_method,
field_name = field_name
))
.unwrap();
clone_from.write_fmt(format_args!("*{field_name} = {clone_trait}::{clone_method}(___{field_name});", clone_trait = clone_trait, clone_method = clone_method, field_name = field_name)).unwrap();
}
None => {
match clone_method {
Some(clone_method) => {
clone
.write_fmt(format_args!(
"{clone_method}({field_name}),",
clone_method = clone_method,
field_name = field_name
))
.unwrap();
clone_from.write_fmt(format_args!("*{field_name} = {clone_method}(___{field_name});", clone_method = clone_method, field_name = field_name)).unwrap();
}
None => {
clone
.write_fmt(format_args!(
"core::clone::Clone::clone({field_name}),",
field_name = field_name
))
.unwrap();
clone_from.write_fmt(format_args!("core::clone::Clone::clone_from({field_name}, ___{field_name});", field_name = field_name)).unwrap();
}
}
}
}
}
clone.push(')');
clone_match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} ( {pattern_tokens} ) => {{ {clone} }}", enum_name = enum_name, variant_ident = variant_ident, pattern_tokens = pattern_tokens, clone = clone)).unwrap();
clone_from_match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} ( {pattern_2_tokens} ) => {{ if let {enum_name}::{variant_ident} ( {pattern_3_tokens} ) = _source {{ {block_tokens} done = true; }} }}", enum_name = enum_name, variant_ident = variant_ident, pattern_2_tokens = pattern_2_tokens, pattern_3_tokens = pattern_3_tokens, block_tokens = clone_from)).unwrap();
} else {
let mut clone = format!(
"{enum_name}::{variant_ident} {{",
enum_name = enum_name,
variant_ident = variant_ident
);
let mut clone_from = String::new();
for field_name in field_names {
pattern_tokens
.write_fmt(format_args!(
"{field_name},",
field_name = field_name
))
.unwrap();
pattern_2_tokens
.write_fmt(format_args!(
"{field_name},",
field_name = field_name
))
.unwrap();
pattern_3_tokens
.write_fmt(format_args!(
"{field_name}: ___{field_name},",
field_name = field_name
))
.unwrap();
}
for (index, field_attribute) in field_attributes.iter().enumerate() {
let field_name = &field_names[index];
let clone_trait = &field_attribute.clone_trait;
let clone_method = &field_attribute.clone_method;
match clone_trait {
Some(clone_trait) => {
let clone_method = clone_method.as_ref().unwrap();
clone.write_fmt(format_args!("{field_name}: {clone_trait}::{clone_method}({field_name}),", clone_trait = clone_trait, clone_method = clone_method, field_name = field_name)).unwrap();
clone_from.write_fmt(format_args!("*{field_name} = {clone_trait}::{clone_method}(___{field_name});", clone_trait = clone_trait, clone_method = clone_method, field_name = field_name)).unwrap();
}
None => {
match clone_method {
Some(clone_method) => {
clone.write_fmt(format_args!("{field_name}: {clone_method}({field_name}),", clone_method = clone_method, field_name = field_name)).unwrap();
clone_from.write_fmt(format_args!("*{field_name} = {clone_method}(___{field_name});", clone_method = clone_method, field_name = field_name)).unwrap();
}
None => {
clone.write_fmt(format_args!("{field_name}: core::clone::Clone::clone({field_name}),", field_name = field_name)).unwrap();
clone_from.write_fmt(format_args!("core::clone::Clone::clone_from({field_name}, ___{field_name});", field_name = field_name)).unwrap();
}
}
}
}
}
clone.push('}');
clone_match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} {{ {pattern_tokens} }} => {{ {clone} }}", enum_name = enum_name, variant_ident = variant_ident, pattern_tokens = pattern_tokens, clone = clone)).unwrap();
clone_from_match_tokens.write_fmt(format_args!("{enum_name}::{variant_ident} {{ {pattern_2_tokens} }} => {{ if let {enum_name}::{variant_ident} {{ {pattern_3_tokens} }} = _source {{ {block_tokens} }} done = true; }}", enum_name = enum_name, variant_ident = variant_ident, pattern_2_tokens = pattern_2_tokens, pattern_3_tokens = pattern_3_tokens, block_tokens = clone_from)).unwrap();
}
}
}
clone_match_tokens.push('}');
clone_from_match_tokens.push('}');
clone_tokens.extend(TokenStream::from_str(&clone_match_tokens).unwrap());
clone_from_tokens.extend(TokenStream::from_str(&clone_from_match_tokens).unwrap());
}
}
let ident = &ast.ident;
let mut generics_cloned: Generics = ast.generics.clone();
let where_clause = generics_cloned.make_where_clause();
for where_predicate in bound {
where_clause.predicates.push(where_predicate);
}
let (impl_generics, ty_generics, where_clause) = generics_cloned.split_for_impl();
let compare_impl = quote! {
impl #impl_generics core::clone::Clone for #ident #ty_generics #where_clause {
#[inline]
fn clone(&self) -> Self {
#clone_tokens
}
#[inline]
fn clone_from(&mut self, _source: &Self) {
let mut done = false;
#clone_from_tokens
if !done {
*self = core::clone::Clone::clone(_source);
}
}
}
};
tokens.extend(compare_impl);
}
}
