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use crate::cmp::StructCmpConfig;
use crate::config::field_config::{GetterType, SetterType};
use crate::utils::collect_meta::collect_meta_set;
use crate::ops::StructOpsConfig;
use proc_macro2::Span;
use syn::spanned::Spanned;
use syn::{Attribute, Lit, Meta, MetaList, MetaNameValue, NestedMeta};
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct StructConfig {
pub generate_default: bool,
pub const_default: bool,
pub impl_std_default: bool,
pub partial_default: bool,
pub manual_debug: bool,
pub override_auto_get: GetterType,
pub override_auto_set: SetterType,
pub cmp: StructCmpConfig,
pub ops: StructOpsConfig
}
impl StructConfig {
pub fn from_attribute(
attrs: Vec<Attribute>,
parent_span: Span,
) -> Result<(Self, Vec<Attribute>), syn::Error> {
let mut config = StructConfig {
generate_default: false,
const_default: false,
impl_std_default: false,
partial_default: false,
manual_debug: false,
override_auto_get: GetterType::No,
override_auto_set: SetterType::No,
cmp: Default::default(),
ops: Default::default(),
};
let mut avec = Vec::with_capacity(attrs.len());
for attr in attrs {
if let Ok(Some(ml)) = meta_list_from_attr(&attr) {
for meta in ml.nested {
if let NestedMeta::Meta(meta) = meta {
if meta.path().is_ident("default") {
match meta {
Meta::Path(_) => config.generate_default = true,
Meta::NameValue(
MetaNameValue {
lit: Lit::Bool(lit),
..
}) => config.generate_default = lit.value,
_ => return Err(syn::Error::new(
meta.span(),
"`default` argument should be like `default = true` or simply `default`",
))
};
continue;
} else if meta.path().is_ident("const") {
match meta {
Meta::Path(_) => config.const_default = true,
Meta::NameValue(
MetaNameValue {
lit: Lit::Bool(lit),
..
}) => config.const_default = lit.value,
_ => return Err(syn::Error::new(
meta.span(),
"`const` argument should be like `const = true` or simply `const`",
))
}
continue;
} else if meta.path().is_ident("std_default") {
match meta {
Meta::Path(_) => config.impl_std_default = true,
Meta::NameValue(
MetaNameValue {
lit: Lit::Bool(lit),
..
}) => config.impl_std_default = lit.value,
_ => return Err(syn::Error::new(
meta.span(),
"`std_default` argument should be like `std_default = true` or simply `std_default`",
))
}
continue;
} else if meta.path().is_ident("debug") {
match meta {
Meta::Path(_) => config.manual_debug = true,
Meta::NameValue(
MetaNameValue {
lit: Lit::Bool(lit),
..
}) => config.manual_debug = lit.value,
_ => return Err(syn::Error::new(
meta.span(),
"`debug` argument should be like `debug = true` or simply `debug`",
))
}
continue;
} else if meta.path().is_ident("partial") {
match meta {
Meta::Path(_) => config.partial_default = true,
Meta::NameValue(
MetaNameValue {
lit: Lit::Bool(lit),
..
}) => config.const_default = lit.value,
_ => return Err(syn::Error::new(
meta.span(),
"`partial` argument should be like `partial = true` or simply `partial`",
))
}
continue;
} else if meta.path().is_ident("set") {
match meta {
Meta::Path(_) => config.override_auto_set = Default::default(),
Meta::NameValue(
MetaNameValue {
lit: Lit::Str(lit), ..
}) => {
config.override_auto_set = SetterType::from_str(lit.value())
.ok_or_else(|| {
syn::Error::new(lit.span(), "unknown `set` type")
})?
}
_ => return Err(syn::Error::new(
meta.span(),
"invalid `set` value, see the documentation for more information",
))
}
continue;
} else if meta.path().is_ident("get") {
match meta {
Meta::Path(_) => config.override_auto_get = Default::default(),
Meta::NameValue(
MetaNameValue {
lit: Lit::Str(lit), ..
}) => {
config.override_auto_get = GetterType::from_str(lit.value())
.ok_or_else(|| {
syn::Error::new(lit.span(), "unknown `get` type")
})?
}
_ => return Err(syn::Error::new(
meta.span(),
"invalid `get` value, see the documentation for more information",
))
}
continue;
} else if meta.path().is_ident("cmp") {
match meta {
Meta::List(ml) => {
collect_meta_set(&ml, |item, span| {
match item {
"eq" => config.cmp.eq = true,
"peq" | "partial_eq" => config.cmp.partial_eq = true,
"ord" | "cmp" => config.cmp.ord = true,
"partial_ord" | "pord" | "partial_cmp" | "pcmp" => config.cmp.partial_ord = true,
_ => return Err(syn::Error::new(span, "invalid `cmp` value"))
};
Ok(())
})?;
}
_ => return Err(syn::Error::new(
meta.span(),
"invalid `cmp` value, see the documentation for more information",
))
}
} else if meta.path().is_ident("ops") {
match meta {
Meta::List(ml) => config.ops.mut_and(StructOpsConfig::from_meta(&ml)?),
_ => return Err(syn::Error::new(
meta.span(),
"invalid `cmp` value, see the documentation for more information",
))
}
}
}
}
}
avec.push(attr);
}
if (config.generate_default || config.const_default) && config.partial_default {
return Err(syn::Error::new(
parent_span,
"partial default does nothing if all fields have default values.",
));
}
Ok((config, avec))
}
}
fn meta_list_from_attr(attr: &Attribute) -> syn::Result<Option<MetaList>> {
if let Meta::List(meta_list) = attr.parse_meta()? {
if meta_list.path.is_ident("dstruct") {
return Ok(Some(meta_list));
}
}
Ok(None)
}