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 |
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 | |
60 | impl<'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 | |
75 | impl ToTokens for FromTypeParamOptions { |
76 | fn to_tokens(&self, tokens: &mut TokenStream) { |
77 | FromTypeParamImpl::from(self).to_tokens(tokens) |
78 | } |
79 | } |
80 | |