#macro #templating #template #struct #field #name #declare

macro macro_macro

Macro templating library for DRYer structs

1 unstable release

0.1.0 May 2, 2020

#10 in #declare

MIT license

11KB
164 lines

macro!macro!

Rust macro templating library for cleaner code.

Usage

Declare a named template with the macros you want to use. The template treats some items specially:

  • __ : one double underscore can be used alone as a name wildcard or for prefix and/or suffix matching
  • ! : for a type wildcard

Examples

Name prefix matching on struct and field name:

macro_template!(prefix_match = {
  #...
  struct STRUCT_PREFIX__ {
    #... FIELD_PREFIX__: !,
  }
});

Type matching for field macros:

macro_template!(field_type_match = {
  struct __ {
    #... __: i32,
  }
});

which would add the declared attribute macro(s) to any fields in a struct with type i32.

Full example for serde annotation macros:

use macro_macro::*;
use serde::{Deserialize, Serialize};

macro_template!(serde_service_model = {
  #[derive(Default, Debug, Clone, Serialize, Deserialize)]
  #[serde(rename_all = "camelCase")]
  struct __ {
    #[serde(skip_serializing_if = "Option::is_none")] __: Option<!>,
  }
});

#[macro_macro(serde_service_model)]
pub struct Service {
    pub version: String,
    pub metadata: Option<Metadata>,
    ...
}

#[macro_macro(serde_service_model)]
pub struct Metadata {
    pub api_version: Option<String>,
    pub endpoint_prefix: Option<String>,
    ...
}

which is equivalent to annotating each struct directly with:

#[derive(Default, Debug, Clone, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]

and each field of type Option with:

#[serde(skip_serializing_if = "Option::is_none")]

License

Licensed under:

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed as above, without any additional terms or conditions.

Dependencies

~1.5MB
~34K SLoC