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
41 .ident
42 .as_ref()
43 .map(|v| v.to_string())
44 .as_ref()
45 .map(|v| v.as_str())
46 {
47 Some("bounds") => {
48 self.bounds = field.ident.clone();
49 Ok(())
50 }
51 Some("default") => {
52 self.default = field.ident.clone();
53 Ok(())
54 }
55 _ => self.base.parse_field(field),
56 }
57 }
58}
59
60impl<'a> From<&'a FromTypeParamOptions> for FromTypeParamImpl<'a> {
61 fn from(v: &'a FromTypeParamOptions) -> Self {
62 FromTypeParamImpl {
63 base: (&v.base.container).into(),
64 ident: v.base.ident.as_ref(),
65 attrs: v.base.attrs.as_ref(),
66 bounds: v.bounds.as_ref(),
67 default: v.default.as_ref(),
68 attr_names: &v.base.attr_names,
69 forward_attrs: v.base.forward_attrs.as_ref(),
70 from_ident: v.base.from_ident,
71 }
72 }
73}
74
75impl ToTokens for FromTypeParamOptions {
76 fn to_tokens(&self, tokens: &mut TokenStream) {
77 FromTypeParamImpl::from(self).to_tokens(tokens)
78 }
79}
80