Merge pull request #61 from kadiwa4/syn_2

update to syn 2

.travis.yml

@@ -3,7 +3,7 @@ language: rust
 
 matrix:
  include:
- - rust: 1.31.0
+ - rust: 1.56.1
  - rust: stable
  - rust: beta
  - rust: nightly

Cargo.toml

@@ -12,7 +12,7 @@ proc-macro = true
 [dependencies]
 proc-macro2 = "1"
 quote = "1"
-syn = "1"
+syn = "2"
 
 [features]
 default = ["std"]

src/lib.rs

@@ -23,15 +23,15 @@
 //!
 //! ```rust
 //! use derive_new::new;
-//! 
+//!
 //! fn main() {}
 //! ```
 //!
 //! Generating constructor for a simple struct:
 //!
 //! ```rust
 //! use derive_new::new;
-//! 
+//!
 //! #[derive(new)]
 //! struct Bar {
 //! a: i32,
@@ -49,7 +49,7 @@
 //!
 //! ```rust
 //! use derive_new::new;
-//! 
+//!
 //! #[derive(new)]
 //! struct Foo {
 //! x: bool,
@@ -69,7 +69,7 @@
 //!
 //! ```rust
 //! use derive_new::new;
-//! 
+//!
 //! use std::marker::PhantomData;
 //!
 //! #[derive(new)]
@@ -91,7 +91,7 @@
 //!
 //! ```rust
 //! use derive_new::new;
-//! 
+//!
 //! #[derive(new)]
 //! enum Enum {
 //! FirstVariant,
@@ -124,7 +124,7 @@ fn path_to_string(path: &syn::Path) -> String {
 
 use proc_macro::TokenStream;
 use proc_macro2::TokenStream as TokenStream2;
-use syn::Token;
+use syn::{Token, punctuated::Punctuated};
 
 #[proc_macro_derive(new, attributes(new))]
 pub fn derive(input: TokenStream) -> TokenStream {
@@ -164,7 +164,7 @@ fn new_for_enum(ast: &syn::DeriveInput, data: &syn::DataEnum) -> proc_macro2::To
 
 fn new_impl(
  ast: &syn::DeriveInput,
- fields: Option<&syn::punctuated::Punctuated<syn::Field, Token![,]>>,
+ fields: Option<&Punctuated<syn::Field, Token![,]>>,
  named: bool,
  variant: Option<&syn::Ident>,
 ) -> proc_macro2::TokenStream {
@@ -227,9 +227,11 @@ fn collect_parent_lint_attrs(attrs: &[syn::Attribute]) -> Vec<syn::Attribute> {
 
  fn is_cfg_attr_lint(item: &syn::Meta) -> bool {
  if let syn::Meta::List(ref l) = *item {
- if l.path.is_ident("cfg_attr") && l.nested.len() == 2 {
- if let syn::NestedMeta::Meta(ref item) = l.nested[1] {
- return is_lint(item);
+ if l.path.is_ident("cfg_attr") {
+ if let Ok(nested) =
+ l.parse_args_with(Punctuated::<syn::Meta, Token![,]>::parse_terminated)
+ {
+ return nested.len() == 2 && is_lint(&nested[1]);
  }
  }
  }
@@ -238,9 +240,7 @@ fn collect_parent_lint_attrs(attrs: &[syn::Attribute]) -> Vec<syn::Attribute> {
 
  attrs
  .iter()
- .filter_map(|a| a.parse_meta().ok().map(|m| (m, a)))
- .filter(|&(ref m, _)| is_lint(m) || is_cfg_attr_lint(m))
- .map(|p| p.1)
+ .filter(|a| is_lint(&a.meta) || is_cfg_attr_lint(&a.meta))
  .cloned()
  .collect()
 }
@@ -259,48 +259,44 @@ impl FieldAttr {
  }
 
  pub fn parse(attrs: &[syn::Attribute]) -> Option<FieldAttr> {
- use syn::{AttrStyle, Meta, NestedMeta};
-
  let mut result = None;
  for attr in attrs.iter() {
  match attr.style {
- AttrStyle::Outer => {}
+ syn::AttrStyle::Outer => {}
  _ => continue,
  }
  let last_attr_path = attr
- .path
+ .path()
  .segments
- .iter()
  .last()
  .expect("Expected at least one segment where #[segment[::segment*](..)]");
  if (*last_attr_path).ident != "new" {
  continue;
  }
- let meta = match attr.parse_meta() {
- Ok(meta) => meta,
- Err(_) => continue,
- };
- let list = match meta {
- Meta::List(l) => l,
- _ if meta.path().is_ident("new") => {
+ let list = match attr.meta {
+ syn::Meta::List(ref l) => l,
+ _ if attr.path().is_ident("new") => {
  panic!("Invalid #[new] attribute, expected #[new(..)]")
  }
  _ => continue,
  };
  if result.is_some() {
  panic!("Expected at most one #[new] attribute");
  }
- for item in list.nested.iter() {
- match *item {
- NestedMeta::Meta(Meta::Path(ref path)) => {
+ for item in list
+ .parse_args_with(Punctuated::<syn::Meta, Token![,]>::parse_terminated)
+ .unwrap_or_else(|err| panic!("Invalid #[new] attribute: {}", err))
+ {
+ match item {
+ syn::Meta::Path(path) => {
  if path.is_ident("default") {
  result = Some(FieldAttr::Default);
  } else {
  panic!("Invalid #[new] attribute: #[new({})]", path_to_string(&path));
  }
  }
- NestedMeta::Meta(Meta::NameValue(ref kv)) => {
- if let syn::Lit::Str(ref s) = kv.lit {
+ syn::Meta::NameValue(kv) => {
+ if let syn::Expr::Lit(syn::ExprLit { lit: syn::Lit::Str(ref s), .. }) = kv.value {
  if kv.path.is_ident("value") {
  let tokens = lit_str_to_token_stream(s).ok().expect(&format!(
  "Invalid expression in #[new]: `{}`",
@@ -314,12 +310,9 @@ impl FieldAttr {
  panic!("Non-string literal value in #[new] attribute");
  }
  }
- NestedMeta::Meta(Meta::List(ref l)) => {
+ syn::Meta::List(l) => {
  panic!("Invalid #[new] attribute: #[new({}(..))]", path_to_string(&l.path));
  }
- NestedMeta::Lit(_) => {
- panic!("Invalid #[new] attribute: literal value in #[new(..)]");
- }
  }
  }
  }