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// Copyright (c) 2017-present PyO3 Project and Contributors
use syn;
use quote::{Tokens, Ident};
use args::{Argument, parse_arguments};
use utils::for_err_msg;
#[derive(Clone, Debug)]
pub struct FnArg<'a> {
pub name: &'a syn::Ident,
pub mode: &'a syn::BindingMode,
pub ty: &'a syn::Ty,
pub optional: Option<&'a syn::Ty>,
pub py: bool,
pub reference: bool,
}
#[derive(Clone, PartialEq, Debug)]
pub enum FnType {
Getter(Option<String>),
Setter(Option<String>),
Fn,
FnNew,
FnInit,
FnCall,
FnClass,
FnStatic,
}
pub struct FnSpec<'a> {
pub tp: FnType,
pub attrs: Vec<Argument>,
pub args: Vec<FnArg<'a>>,
pub output: syn::Ty,
}
impl<'a> FnSpec<'a> {
/// Parser function signature and function attributes
pub fn parse(name: &'a syn::Ident,
sig: &'a syn::MethodSig,
meth_attrs: &'a mut Vec<syn::Attribute>) -> FnSpec<'a> {
let (fn_type, fn_attrs) = parse_attributes(meth_attrs);
let mut has_self = false;
let mut arguments = Vec::new();
for input in sig.decl.inputs.iter() {
match input {
&syn::FnArg::SelfRef(_, _) => {
has_self = true;
},
&syn::FnArg::SelfValue(_) => {
has_self = true;
}
&syn::FnArg::Captured(ref pat, ref ty) => {
// skip first argument (cls)
if (fn_type == FnType::FnClass || fn_type == FnType::FnNew) && !has_self {
has_self = true;
continue
}
let (mode, ident) = match pat {
&syn::Pat::Ident(ref mode, ref ident, _) =>
(mode, ident),
_ =>
panic!("unsupported argument: {:?}", pat),
};
let py = match ty {
&syn::Ty::Path(_, ref path) =>
if let Some(segment) = path.segments.last() {
segment.ident.as_ref() == "Python"
} else {
false
},
_ => false
};
let opt = check_arg_ty_and_optional(name, ty);
arguments.push(
FnArg {
name: ident,
mode: mode,
ty: ty,
optional: opt,
py: py,
reference: is_ref(name, ty),
}
);
}
&syn::FnArg::Ignored(_) =>
panic!("ignored argument: {:?}", name),
}
}
let ty = match sig.decl.output {
syn::FunctionRetTy::Default => syn::Ty::Infer,
syn::FunctionRetTy::Ty(ref ty) => ty.clone()
};
FnSpec {
tp: fn_type,
attrs: fn_attrs,
args: arguments,
output: ty,
}
}
pub fn is_args(&self, name: &syn::Ident) -> bool {
for s in self.attrs.iter() {
match *s {
Argument::VarArgs(ref ident) =>
return name.as_ref() == ident.as_str(),
_ => (),
}
}
false
}
pub fn accept_args(&self) -> bool {
for s in self.attrs.iter() {
match *s {
Argument::VarArgs(_) => return true,
Argument::VarArgsSeparator => return true,
_ => (),
}
}
false
}
pub fn is_kwargs(&self, name: &syn::Ident) -> bool {
for s in self.attrs.iter() {
match *s {
Argument::KeywordArgs(ref ident) =>
return name.as_ref() == ident.as_str(),
_ => (),
}
}
false
}
pub fn accept_kwargs(&self) -> bool {
for s in self.attrs.iter() {
match *s {
Argument::KeywordArgs(_) => return true,
_ => (),
}
}
false
}
pub fn default_value(&self, name: &syn::Ident) -> Option<Tokens> {
for s in self.attrs.iter() {
match *s {
Argument::Arg(ref ident, ref opt) => {
if ident.as_str() == name.as_ref() {
if let &Some(ref val) = opt {
let i = Ident::from(val.as_str());
return Some(quote!(#i))
}
}
},
Argument::Kwarg(ref ident, ref opt) => {
if ident.as_str() == name.as_ref() {
let i = Ident::from(opt.as_str());
return Some(quote!(#i))
}
},
_ => (),
}
}
None
}
pub fn is_kw_only(&self, name: &syn::Ident) -> bool {
for s in self.attrs.iter() {
match *s {
Argument::Kwarg(ref ident, _) => {
if ident.as_str() == name.as_ref() {
return true
}
},
_ => (),
}
}
false
}
}
pub fn is_ref<'a>(name: &'a syn::Ident, ty: &'a syn::Ty) -> bool {
match ty {
&syn::Ty::Rptr(_, _) => {
return true
}
&syn::Ty::Path(_, ref path) => {
if let Some(segment) = path.segments.last() {
match segment.ident.as_ref() {
"Option" => {
match segment.parameters {
syn::PathParameters::AngleBracketed(ref params) => {
if params.types.len() != 1 {
panic!("argument type is not supported by python method: {:?} ({:?}) {:?}",
for_err_msg(name),
for_err_msg(ty),
for_err_msg(path));
}
match ¶ms.types[params.types.len()-1] {
&syn::Ty::Rptr(_, _) => {
return true
},
_ => ()
}
},
_ => {
panic!("argument type is not supported by python method: {:?} ({:?}) {:?}",
for_err_msg(name),
for_err_msg(ty),
for_err_msg(path));
}
}
},
_ => (),
}
}
},
_ => ()
}
false
}
pub fn check_arg_ty_and_optional<'a>(name: &'a syn::Ident, ty: &'a syn::Ty)
-> Option<&'a syn::Ty>
{
match ty {
&syn::Ty::Path(_, ref path) => {
//if let &Some(ref qs) = qs {
// panic!("explicit Self type in a 'qualified path' is not supported: {:?} - {:?}",
// name, qs);
//}
if let Some(segment) = path.segments.last() {
match segment.ident.as_ref() {
"Option" => {
match segment.parameters {
syn::PathParameters::AngleBracketed(ref params) => {
if params.types.len() != 1 {
panic!("argument type is not supported by python method: {:?} ({:?}) {:?}",
for_err_msg(name),
for_err_msg(ty),
for_err_msg(path));
}
Some(¶ms.types[0])
},
_ => {
panic!("argument type is not supported by python method: {:?} ({:?}) {:?}",
for_err_msg(name),
for_err_msg(ty),
for_err_msg(path));
}
}
},
_ => None,
}
} else {
None
}
},
_ => {
None
//panic!("argument type is not supported by python method: {:?} ({:?})",
//for_err_msg(name),
//for_err_msg(ty));
},
}
}
fn parse_attributes(attrs: &mut Vec<syn::Attribute>) -> (FnType, Vec<Argument>) {
let mut new_attrs = Vec::new();
let mut spec = Vec::new();
let mut res: Option<FnType> = None;
for attr in attrs.iter() {
match attr.value {
syn::MetaItem::Word(ref name) => {
match name.as_ref() {
"new" | "__new__" => {
res = Some(FnType::FnNew)
},
"init" | "__init__" => {
res = Some(FnType::FnInit)
},
"call" | "__call__" => {
res = Some(FnType::FnCall)
},
"classmethod" => {
res = Some(FnType::FnClass)
},
"staticmethod" => {
res = Some(FnType::FnStatic)
},
"setter" | "getter" => {
if attr.style == syn::AttrStyle::Inner {
panic!("Inner style attribute is not
supported for setter and getter");
}
if res != None {
panic!("setter/getter attribute can not be used mutiple times");
}
if name.as_ref() == "setter" {
res = Some(FnType::Setter(None))
} else {
res = Some(FnType::Getter(None))
}
},
_ => {
new_attrs.push(attr.clone())
}
}
},
syn::MetaItem::List(ref name, ref meta) => {
match name.as_ref() {
"new" => {
res = Some(FnType::FnNew)
},
"init" => {
res = Some(FnType::FnInit)
},
"call" => {
res = Some(FnType::FnCall)
},
"setter" | "getter" => {
if attr.style == syn::AttrStyle::Inner {
panic!("Inner style attribute is not
supported for setter and getter");
}
if res != None {
panic!("setter/getter attribute can not be used mutiple times");
}
if meta.len() != 1 {
panic!("setter/getter requires one value");
}
match *meta.first().unwrap() {
syn::NestedMetaItem::MetaItem(syn::MetaItem::Word(ref w)) => {
if name.as_ref() == "setter" {
res = Some(FnType::Setter(Some(w.to_string())))
} else {
res = Some(FnType::Getter(Some(w.to_string())))
}
},
syn::NestedMetaItem::Literal(ref lit) => {
match *lit {
syn::Lit::Str(ref s, syn::StrStyle::Cooked) => {
if name.as_ref() == "setter" {
res = Some(FnType::Setter(Some(s.clone())))
} else {
res = Some(FnType::Getter(Some(s.clone())))
}
},
_ => {
panic!("setter/getter attribute requires str value");
},
}
}
_ => {
println!("cannot parse {:?} attribute: {:?}", name, meta);
},
}
},
"args" => {
spec.extend(parse_arguments(meta.as_slice()))
}
_ => {
new_attrs.push(attr.clone())
}
}
},
syn::MetaItem::NameValue(_, _) => {
new_attrs.push(attr.clone())
},
}
}
attrs.clear();
attrs.extend(new_attrs);
match res {
Some(tp) => (tp, spec),
None => (FnType::Fn, spec),
}
}