memtable-macros 0.2.0

Macro library that provides ability to derive typed tables and generate tables compile-time.
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

use syn::{parse_quote, Ident, ItemFn, Path, Type};

pub struct Args<'a> {
    pub root: &'a Path,
    pub idx: &'a syn::Index,
    pub method_name: &'a Ident,
    pub variant_ty: &'a Type,
    pub table_data_name: &'a Ident,
    pub as_variant: &'a Ident,
}

pub fn make(args: Args) -> ItemFn {
    let Args {
        root,
        idx,
        method_name,
        variant_ty,
        table_data_name,
        as_variant,
    } = args;

    parse_quote! {
        pub fn #method_name(
            &self,
            row: ::core::primitive::usize,
        ) -> ::core::option::Option<&#variant_ty> {
            #root::Table::cell(&self.0, row, #idx)
                .and_then(#table_data_name::#as_variant)
        }
    }
}