derivor 0.0.1

Some useful Derive(Trait) macro options.
Documentation 
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
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138

pub(crate) mod constants;
#[cfg(feature = "enums")]
pub(crate) mod enums;
#[cfg(any(feature = "enums", feature = "structs", feature = "unions"))]
pub(crate) mod fields;
#[cfg(feature = "structs")]
pub(crate) mod structs;
#[cfg(feature = "unions")]
pub(crate) mod unions;

use constants::CTOR_WORD;
#[cfg(feature = "enums")]
use enums::create_enum_token_stream;
#[cfg(feature = "structs")]
use structs::create_struct_token_stream;
#[cfg(feature = "unions")]
use unions::create_union_token_stream;


use {
    alloc::{
        format,
        string::{
            String, ToString
        },
    },
    quote::ToTokens,
    proc_macro::{
        TokenStream,
    },
    proc_macro2::{
        Delimiter, Ident, Span
    },
    syn::{
        token::Pub,
        spanned::Spanned,
        parse::{
            Parse, ParseStream,
            discouraged::AnyDelimiter,
        },
        parse_macro_input, Data, DeriveInput, Error, Type, Visibility,
    },
    crate::{
        BTreeSet,
    }
};

pub(crate) struct Definition {
    pub(crate) visibility: Visibility,
    pub(crate) ident: Ident,
    pub(crate) attrs: BTreeSet<Attribute>,
}

#[derive(Hash, PartialEq, Eq, PartialOrd, Ord)]
pub(crate) enum Attribute {
    Const,
    DefaultAll,
    Default,
    IntoAll,
}

impl Default for Definition {
    fn default() -> Self {
        Self {
            visibility: Visibility::Public(Pub {
                span: Span::call_site(),
            }),
            ident: Ident::new("new", Span::mixed_site()),
            attrs: Default::default(),
        }
    }
}

pub(crate) fn adjust_keyword_ident(name: String) -> String {
    if syn::parse_str::<Ident>(&name).is_ok() {
        return name;
    }

    format!("r#{}", name)
}

#[cfg(not(any(feature = "enums", feature = "structs", feature = "unions")))]
pub(crate) fn derive_ctor_internal(input: TokenStream) -> TokenStream {
    let derive_input = parse_macro_input!(input as DeriveInput);

    match &derive_input.data {
        Data::Struct(_) => crate::create_struct(derive_input),
        Data::Enum(_) => crate::create_enum(derive_input),
        Data::Union(_) => crate::create_union(derive_input)
    }
}

pub(crate) fn parse_attributes_with_default<T: Parse, F: Fn() -> T>(
    attributes: &[syn::Attribute],
    default: F,
) -> Result<T, Error> {
    for attribute in attributes {
        if attribute.path().is_ident(CTOR_WORD) {
            return attribute.parse_args::<T>();
        }
    }
    Ok(default())
}

pub(crate) fn parse_attributes<T: Parse>(attributes: &[syn::Attribute]) -> Result<Option<T>, Error> {
    for attribute in attributes {
        if attribute.path().is_ident(CTOR_WORD) {
            return attribute.parse_args::<T>().map(Some);
        }
    }
    Ok(None)
}

pub(crate) fn is_phantom(typ: &Type) -> bool {
    for token in typ.to_token_stream() {
        if token.to_string() == "PhantomData" {
            return true;
        }
    }
    false
}

pub(crate) fn consume_delimited<T, F>(
    stream: ParseStream,
    expected: Delimiter,
    expression: F,
) -> Result<T, Error>
where
    F: Fn(ParseStream) -> Result<T, Error>,
{
    let (delimiter, span, buffer) = stream.parse_any_delimiter()?;
    if delimiter != expected {
        return Err(Error::new(span.span(),
                              format!("Expected enclosing {:?}", expected),
        ));
    }
    expression(&buffer)
}