Get synom compiling again

Add a `Synom` trait along with impls for all the base types here, to be used
later.

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "syn"
-version = "0.12.0" # don't forget to update version in readme for breaking changes
+version = "0.11.11" # don't forget to update version in readme for breaking changes
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Nom parser for Rust source code"
@@ -18,14 +18,14 @@ parsing = ["unicode-xid", "synom/parsing"]
 printing = ["quote", "synom/printing"]
 visit = []
 fold = []
-clone-impls = []
-extra-traits = []
+clone-impls = ["synom/clone-impls"]
+extra-traits = ["synom/extra-traits"]
 
 [dependencies]
 quote = { git = 'https://github.com/dtolnay/quote', optional = true }
 proc-macro2 = { git = 'https://github.com/alexcrichton/proc-macro2' }
 unicode-xid = { version = "0.0.4", optional = true }
-synom = { version = "0.11", path = "synom", default-features = true }
+synom = { version = "0.11", path = "synom" }
 
 [dev-dependencies]
 syntex_pos = "0.58"

synom/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "synom"
-version = "0.12.0"
+version = "0.11.3"
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 license = "MIT/Apache-2.0"
 description = "Stripped-down Nom parser used by Syn"
@@ -14,17 +14,17 @@ publish = false # this branch contains breaking changes
 [dependencies]
 quote = { git = 'https://github.com/dtolnay/quote', optional = true }
 unicode-xid = "0.0.4"
+proc-macro2 = { git = 'https://github.com/alexcrichton/proc-macro2' }
 
 [features]
 printing = ["quote"]
 parsing = []
-default = ["parsing"]
-
-[dev-dependencies]
-proc-macro2 = { git = 'https://github.com/alexcrichton/proc-macro2' }
+default = []
+clone-impls = []
+extra-traits = []
 
 [dev-dependencies.syn]
-version = "0.12"
+version = "0.11"
 path = ".."
 features = ["parsing", "full", "extra-traits"]
 default-features = false

synom/src/delimited.rs

@@ -2,7 +2,8 @@ use std::iter::FromIterator;
 use std::slice;
 use std::vec;
 
-#[derive(Eq, PartialEq, Hash, Debug, Clone)]
+#[cfg_attr(feature = "extra-traits", derive(Eq, PartialEq, Hash, Debug))]
+#[cfg_attr(feature = "clone-impls", derive(Clone))]
 pub struct Delimited<T, D> {
     inner: Vec<(T, Option<D>)>
 }
@@ -221,6 +222,74 @@ impl<T, D> Element<T, D> {
     }
 }
 
+#[cfg(feature = "parsing")]
+mod parsing {
+    use proc_macro2::TokenTree;
+
+    use super::Delimited;
+    use {IResult, Synom};
+
+    impl<T, D> Delimited<T, D>
+        where T: Synom,
+              D: Synom,
+    {
+        pub fn parse_separated(input: &[TokenTree])
+            -> IResult<&[TokenTree], Self>
+        {
+            Self::parse(input, false)
+        }
+
+        pub fn parse_terminated(input: &[TokenTree])
+            -> IResult<&[TokenTree], Self>
+        {
+            Self::parse(input, true)
+        }
+
+        fn parse(mut input: &[TokenTree], terminated: bool)
+            -> IResult<&[TokenTree], Self>
+        {
+            let mut res = Delimited::new();
+
+            // get the first element
+            match T::parse(input) {
+                IResult::Error => IResult::Done(input, res),
+                IResult::Done(i, o) => {
+                    if i.len() == input.len() {
+                        return IResult::Error
+                    }
+                    input = i;
+                    res.push_first(o);
+
+                    // get the separator first
+                    while let IResult::Done(i2, s) = D::parse(input) {
+                        if i2.len() == input.len() {
+                            break;
+                        }
+
+                        // get the element next
+                        if let IResult::Done(i3, o3) = T::parse(i2) {
+                            if i3.len() == i2.len() {
+                                break;
+                            }
+                            res.push_next(o3, s);
+                            input = i3;
+                        } else {
+                            break;
+                        }
+                    }
+                    if terminated {
+                        if let IResult::Done(after, sep) = D::parse(input) {
+                            res.push_trailing(sep);
+                            input = after;
+                        }
+                    }
+                    IResult::Done(input, res)
+                }
+            }
+        }
+    }
+}
+
 #[cfg(feature = "printing")]
 mod printing {
     use super::*;