1 unstable release
0.1.0 | Feb 7, 2023 |
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#1789 in Procedural macros
13KB
254 lines
get_fields
Provides the GetFields
procedural macro.
The macro adds the get_fields
constant to the struct the
macro is dervied on.
The get_fields
contains the field names of the given
struct.
Note: The macro can only be derived from named structs.
Table of Contents
Usage
You can derive the GetFields
macro like this:
use get_fields::GetFields;
#[derive(GetFields)]
struct Foo {
bar: String,
baz: String,
bat: String,
}
assert_eq!(Foo::get_fields, ["bar", "baz", "bat"]);
Attributes
The GetFields
macro supports the
get_fields
attribute.
get_fields
can be applied to the container or to a field
with different arguments listed below.
Container Attributes
Container attributes are global attributes that change the behavior of the whole field names array, rather than that of a single field.
Rename all
The rename_all
attribute renames every field of the struct according
to the provided naming convention.
This attribute works exactly like the serde
equivalent.
Supported are these naming conventions:
lowercase
UPPERCASE
PascalCase
camelCase
snake_case
SCREAMING_SNAKE_CASE
kebab-case
SCREAMING-KEBAB-CASE
use get_fields::GetFields;
#[derive(GetFields)]
#[get_fields(rename_all = "SCREAMING-KEBAB-CASE")]
struct Foo {
field_one: String,
field_two: String,
field_three: String,
}
assert_eq!(
Foo::get_fields,
["FIELD-ONE", "FIELD-TWO", "FIELD-THREE"],
);
Note: Same as serde's implementation of rename_all
, it is
assumed that your field names follow the rust naming convention, that
all field names must be given in snake_case
.
If not, applying rename_all
may result in unexpected field names.
Field Attributes
Field attributes can be added to the fields of a named struct and change the behavior of a single field.
Skip
The skip
attribute removes the field from get_fields
.
use get_fields::GetFields;
#[derive(GetFields)]
struct Foo {
bar: String,
baz: String,
#[get_fields(skip)]
bat: String,
}
assert_eq!(Foo::get_fields, ["bar", "baz"]);
Visibility
The visibility of the get_fields
is the same as the
corresponding struct.
E.g. is it pub struct Foo { ... }
, the get_fields
will be public as well.
This, for example, will work:
mod foo {
use get_fields::GetFields;
#[derive(GetFields)]
pub(super) struct Foo {
bar: String,
baz: String,
bat: String,
}
}
assert_eq!(foo::Foo::get_fields, ["bar", "baz", "bat"]);
Whereas this will not, since get_fields
is private:
mod foo {
use get_fields::GetFields;
#[derive(GetFields)]
struct Foo {
bar: String,
baz: String,
bat: String,
}
}
assert_eq!(foo::Foo::get_fields, ["bar", "baz", "bat"]);
Dependencies
~1.5MB
~36K SLoC