From 36c125629507c97f0320012c15c904bb964885fd Mon Sep 17 00:00:00 2001
From: Ed Page <eopage@gmail.com>
Date: Tue, 14 Dec 2021 14:24:13 -0600
Subject: [PATCH] feat: Supprt parsing dotted keys

We support parsing a lot of expressions to help users to edit their toml
document from real world code.  One thing that was missing was dotted
key parsing.

Also, this will hopefully help with rust-lang/cargo#10176
---
 src/key.rs        | 31 ++++++++++++++++++++++++++++---
 src/parser/mod.rs |  3 ++-
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/key.rs b/src/key.rs
index c9993499..d16df8b4 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -48,6 +48,13 @@ impl Key {
         }
     }
 
+    /// Parse a TOML key expression
+    ///
+    /// Unlike `"".parse<Key>()`, this supports dotted keys.
+    pub fn parse(repr: &str) -> Result<Vec<Self>, parser::TomlError> {
+        Self::try_parse_path(repr)
+    }
+
     pub(crate) fn with_repr_unchecked(mut self, repr: Repr) -> Self {
         self.repr = Some(repr);
         self
@@ -97,12 +104,12 @@ impl Key {
         self.decor.clear();
     }
 
-    fn try_parse(s: &str) -> Result<Key, parser::TomlError> {
+    fn try_parse_simple(s: &str) -> Result<Key, parser::TomlError> {
         use combine::stream::position::{IndexPositioner, Positioner};
         use combine::EasyParser;
 
         let b = s.as_bytes();
-        let result = parser::key_parser().easy_parse(Stream::new(b));
+        let result = parser::simple_key().easy_parse(Stream::new(b));
         match result {
             Ok((_, ref rest)) if !rest.input.is_empty() => Err(parser::TomlError::from_unparsed(
                 (&rest.positioner
@@ -114,6 +121,24 @@ impl Key {
             Err(e) => Err(parser::TomlError::new(e, b)),
         }
     }
+
+    fn try_parse_path(s: &str) -> Result<Vec<Key>, parser::TomlError> {
+        use combine::stream::position::{IndexPositioner, Positioner};
+        use combine::EasyParser;
+
+        let b = s.as_bytes();
+        let result = parser::key_path().easy_parse(Stream::new(b));
+        match result {
+            Ok((_, ref rest)) if !rest.input.is_empty() => Err(parser::TomlError::from_unparsed(
+                (&rest.positioner
+                    as &dyn Positioner<usize, Position = usize, Checkpoint = IndexPositioner>)
+                    .position(),
+                b,
+            )),
+            Ok((keys, _)) => Ok(keys),
+            Err(e) => Err(parser::TomlError::new(e, b)),
+        }
+    }
 }
 
 impl std::ops::Deref for Key {
@@ -158,7 +183,7 @@ impl FromStr for Key {
     /// if fails, tries as basic quoted key (surrounds with "")
     /// and then literal quoted key (surrounds with '')
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Key::try_parse(s)
+        Key::try_parse_simple(s)
     }
 }
 
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 3e9e0e0e..1b9c0e0c 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -17,7 +17,8 @@ mod value;
 
 pub use self::errors::TomlError;
 pub(crate) use self::key::is_unquoted_char;
-pub(crate) use self::key::simple_key as key_parser;
+pub(crate) use self::key::key as key_path;
+pub(crate) use self::key::simple_key;
 pub(crate) use self::value::value as value_parser;
 
 use self::table::duplicate_key;