1 | use proc_macro2::TokenStream; |
2 | use quote::ToTokens; |
3 | use syn::Ident; |
4 | |
5 | use crate::codegen::FromTypeParamImpl; |
6 | use crate::options::{OuterFrom, ParseAttribute, ParseData}; |
7 | use crate::Result; |
8 | |
9 | #[derive (Debug)] |
10 | pub struct FromTypeParamOptions { |
11 | pub base: OuterFrom, |
12 | pub bounds: Option<Ident>, |
13 | pub default: Option<Ident>, |
14 | } |
15 | |
16 | impl 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 | |
28 | impl ParseAttribute for FromTypeParamOptions { |
29 | fn parse_nested(&mut self, mi: &syn::Meta) -> Result<()> { |
30 | self.base.parse_nested(mi) |
31 | } |
32 | } |
33 | |
34 | impl 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: &Ident| v.to_string()).as_deref() { |
41 | Some("bounds" ) => { |
42 | self.bounds = field.ident.clone(); |
43 | Ok(()) |
44 | } |
45 | Some("default" ) => { |
46 | self.default = field.ident.clone(); |
47 | Ok(()) |
48 | } |
49 | _ => self.base.parse_field(field), |
50 | } |
51 | } |
52 | } |
53 | |
54 | impl<'a> From<&'a FromTypeParamOptions> for FromTypeParamImpl<'a> { |
55 | fn from(v: &'a FromTypeParamOptions) -> Self { |
56 | FromTypeParamImpl { |
57 | base: (&v.base.container).into(), |
58 | ident: v.base.ident.as_ref(), |
59 | attrs: v.base.attrs.as_ref(), |
60 | bounds: v.bounds.as_ref(), |
61 | default: v.default.as_ref(), |
62 | attr_names: &v.base.attr_names, |
63 | forward_attrs: v.base.forward_attrs.as_ref(), |
64 | from_ident: v.base.from_ident, |
65 | } |
66 | } |
67 | } |
68 | |
69 | impl ToTokens for FromTypeParamOptions { |
70 | fn to_tokens(&self, tokens: &mut TokenStream) { |
71 | FromTypeParamImpl::from(self).to_tokens(tokens) |
72 | } |
73 | } |
74 | |