1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
use crate::{
derives::{arg_enum, from_arg_matches, into_app, subcommand},
dummies,
};
use proc_macro2::TokenStream;
use proc_macro_error::abort_call_site;
use quote::quote;
use syn::{
self, punctuated::Punctuated, token::Comma, Attribute, Data, DataEnum, DataStruct, DeriveInput,
Field, Fields, Ident,
};
pub fn derive_clap(input: &DeriveInput) -> TokenStream {
let ident = &input.ident;
match input.data {
Data::Struct(DataStruct {
fields: Fields::Named(ref fields),
..
}) => {
dummies::clap_struct(ident);
gen_for_struct(ident, &fields.named, &input.attrs)
}
Data::Struct(DataStruct {
fields: Fields::Unit,
..
}) => {
dummies::clap_struct(ident);
gen_for_struct(ident, &Punctuated::<Field, Comma>::new(), &input.attrs)
}
Data::Enum(ref e) => {
dummies::clap_enum(ident);
gen_for_enum(ident, &input.attrs, e)
}
_ => abort_call_site!("`#[derive(Clap)]` only supports non-tuple structs and enums"),
}
}
fn gen_for_struct(
name: &Ident,
fields: &Punctuated<Field, Comma>,
attrs: &[Attribute],
) -> TokenStream {
let (into_app, attrs) = into_app::gen_for_struct(name, fields, attrs);
let from_arg_matches = from_arg_matches::gen_for_struct(name, fields, &attrs);
quote! {
impl ::clap::Clap for #name {}
#into_app
#from_arg_matches
}
}
fn gen_for_enum(name: &Ident, attrs: &[Attribute], e: &DataEnum) -> TokenStream {
let into_app = into_app::gen_for_enum(name);
let from_arg_matches = from_arg_matches::gen_for_enum(name);
let subcommand = subcommand::gen_for_enum(name, attrs, e);
let arg_enum = arg_enum::gen_for_enum(name, attrs, e);
quote! {
impl ::clap::Clap for #name {}
#into_app
#from_arg_matches
#subcommand
#arg_enum
}
}