darling_core/options/
from_type_param.rs

1use proc_macro2::TokenStream;
2use quote::ToTokens;
3use syn::Ident;
4
5use crate::codegen::FromTypeParamImpl;
6use crate::options::{OuterFrom, ParseAttribute, ParseData};
7use crate::Result;
8
9#[derive(Debug)]
10pub struct FromTypeParamOptions {
11    pub base: OuterFrom,
12    pub bounds: Option<Ident>,
13    pub default: Option<Ident>,
14}
15
16impl FromTypeParamOptions {
17    pub fn new(di: &syn::DeriveInput) -> Result<Self> {
18        (FromTypeParamOptions {
19            base: OuterFrom::start(di)?,
20            bounds: None,
21            default: None,
22        })
23        .parse_attributes(&di.attrs)?
24        .parse_body(&di.data)
25    }
26}
27
28impl ParseAttribute for FromTypeParamOptions {
29    fn parse_nested(&mut self, mi: &syn::Meta) -> Result<()> {
30        self.base.parse_nested(mi)
31    }
32}
33
34impl ParseData for FromTypeParamOptions {
35    fn parse_variant(&mut self, variant: &syn::Variant) -> Result<()> {
36        self.base.parse_variant(variant)
37    }
38
39    fn parse_field(&mut self, field: &syn::Field) -> Result<()> {
40        match field.ident.as_ref().map(|v| v.to_string()).as_deref() {
41            Some("bounds") => {
42                self.bounds.clone_from(&field.ident);
43                Ok(())
44            }
45            Some("default") => {
46                self.default.clone_from(&field.ident);
47                Ok(())
48            }
49            _ => self.base.parse_field(field),
50        }
51    }
52
53    fn validate_body(&self, errors: &mut crate::error::Accumulator) {
54        self.base.validate_body(errors);
55    }
56}
57
58impl<'a> From<&'a FromTypeParamOptions> for FromTypeParamImpl<'a> {
59    fn from(v: &'a FromTypeParamOptions) -> Self {
60        FromTypeParamImpl {
61            base: (&v.base.container).into(),
62            ident: v.base.ident.as_ref(),
63            bounds: v.bounds.as_ref(),
64            default: v.default.as_ref(),
65            attr_names: &v.base.attr_names,
66            forward_attrs: v.base.as_forward_attrs(),
67            from_ident: v.base.from_ident,
68        }
69    }
70}
71
72impl ToTokens for FromTypeParamOptions {
73    fn to_tokens(&self, tokens: &mut TokenStream) {
74        FromTypeParamImpl::from(self).to_tokens(tokens)
75    }
76}
darling_core/options/from_type_param.rs

darling_core/options/
from_type_param.rs
