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use proc_macro2::TokenStream;
use quote::ToTokens;
use syn::Ident;
use crate::codegen::FromTypeParamImpl;
use crate::options::{OuterFrom, ParseAttribute, ParseData};
use crate::Result;
#[derive(Debug)]
pub struct FromTypeParamOptions {
pub base: OuterFrom,
pub bounds: Option<Ident>,
pub default: Option<Ident>,
}
impl FromTypeParamOptions {
pub fn new(di: &syn::DeriveInput) -> Result<Self> {
(FromTypeParamOptions {
base: OuterFrom::start(di)?,
bounds: None,
default: None,
})
.parse_attributes(&di.attrs)?
.parse_body(&di.data)
}
}
impl ParseAttribute for FromTypeParamOptions {
fn parse_nested(&mut self, mi: &syn::Meta) -> Result<()> {
self.base.parse_nested(mi)
}
}
impl ParseData for FromTypeParamOptions {
fn parse_variant(&mut self, variant: &syn::Variant) -> Result<()> {
self.base.parse_variant(variant)
}
fn parse_field(&mut self, field: &syn::Field) -> Result<()> {
match field.ident.as_ref().map(|v| v.to_string()).as_deref() {
Some("bounds") => {
self.bounds = field.ident.clone();
Ok(())
}
Some("default") => {
self.default = field.ident.clone();
Ok(())
}
_ => self.base.parse_field(field),
}
}
}
impl<'a> From<&'a FromTypeParamOptions> for FromTypeParamImpl<'a> {
fn from(v: &'a FromTypeParamOptions) -> Self {
FromTypeParamImpl {
base: (&v.base.container).into(),
ident: v.base.ident.as_ref(),
attrs: v.base.attrs.as_ref(),
bounds: v.bounds.as_ref(),
default: v.default.as_ref(),
attr_names: &v.base.attr_names,
forward_attrs: v.base.forward_attrs.as_ref(),
from_ident: v.base.from_ident,
}
}
}
impl ToTokens for FromTypeParamOptions {
fn to_tokens(&self, tokens: &mut TokenStream) {
FromTypeParamImpl::from(self).to_tokens(tokens)
}
}