use syn::{DeriveInput, Field, Ident, Meta};
use codegen::FromVariantImpl;
use options::{DataShape, OuterFrom, ParseAttribute, ParseData};
use {FromMeta, Result};
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct FromVariantOptions {
pub base: OuterFrom,
pub fields: Option<Ident>,
pub supports: Option<DataShape>,
}
impl FromVariantOptions {
pub fn new(di: &DeriveInput) -> Result<Self> {
(FromVariantOptions {
base: OuterFrom::start(di),
fields: Default::default(),
supports: Default::default(),
}).parse_attributes(&di.attrs)?
.parse_body(&di.data)
}
}
impl<'a> From<&'a FromVariantOptions> for FromVariantImpl<'a> {
fn from(v: &'a FromVariantOptions) -> Self {
FromVariantImpl {
base: (&v.base.container).into(),
ident: v.base.ident.as_ref(),
fields: v.fields.as_ref(),
attrs: v.base.attrs.as_ref(),
attr_names: v.base.attr_names.as_strs(),
forward_attrs: v.base.forward_attrs.as_ref(),
from_ident: v.base.from_ident,
supports: v.supports.as_ref(),
}
}
}
impl ParseAttribute for FromVariantOptions {
fn parse_nested(&mut self, mi: &Meta) -> Result<()> {
match mi.name().as_ref() {
"supports" => {
self.supports = FromMeta::from_meta(mi)?;
Ok(())
}
_ => self.base.parse_nested(mi),
}
}
}
impl ParseData for FromVariantOptions {
fn parse_field(&mut self, field: &Field) -> Result<()> {
match field.ident.as_ref().map(|i| i.as_ref()) {
Some("fields") => {
self.fields = field.ident.clone();
Ok(())
}
_ => self.base.parse_field(field),
}
}
}