dbstruct-derive 0.1.0-alpha

Build a typed database by defining a struct
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

use syn::parse_quote;

use crate::model::{Field, Model};

pub struct Struct {
    pub ident: syn::Ident,
    pub vis: syn::Visibility,
    /// extra variables such as the current length
    /// of the vector wrapper
    pub extra_vars: Vec<syn::Field>,
}

fn as_len_field(field: &Field) -> syn::Field {
    let name = format!("{}_len", field.ident);
    syn::Field {
        attrs: Vec::new(),
        vis: syn::Visibility::Inherited,
        ident: Some(syn::Ident::new(&name, proc_macro2::Span::call_site())),
        colon_token: None,
        ty: parse_quote!(std::sync::Arc<std::sync::atomic::AtomicUsize>),
    }
}

impl From<&Model> for Struct {
    fn from(model: &Model) -> Self {
        let len_vars = model
            .fields
            .iter()
            .filter(|f| f.is_vec())
            .map(as_len_field)
            .collect();
        Struct {
            ident: model.ident.clone(),
            vis: model.vis.clone(),
            extra_vars: len_vars,
        }
    }
}