[librsvg: 26/51] parse_identifiers! - new macro for parsing symbol lists from attributes

[Federico Mena Quintero <federico src gnome org>]

commit 4f5212b369e41efe323fa79303994c0db95ee31c
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Dec 17 19:34:43 2019 -0600

    parse_identifiers! - new macro for parsing symbol lists from attributes

 rsvg_internals/src/lib.rs     |  4 +++-
 rsvg_internals/src/parsers.rs | 27 +++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)
---
diff --git a/rsvg_internals/src/lib.rs b/rsvg_internals/src/lib.rs
index 7b2bd688..e888009f 100644
--- a/rsvg_internals/src/lib.rs
+++ b/rsvg_internals/src/lib.rs
@@ -72,6 +72,9 @@ mod coord_units;
 #[macro_use]
 mod float_eq_cairo;
 
+#[macro_use]
+mod parsers;
+
 #[macro_use]
 mod property_macros;
 
@@ -105,7 +108,6 @@ mod mask;
 mod node;
 mod number_list;
 mod paint_server;
-mod parsers;
 mod path_builder;
 mod path_parser;
 mod pattern;
diff --git a/rsvg_internals/src/parsers.rs b/rsvg_internals/src/parsers.rs
index 3d5b4605..9a6bd17b 100644
--- a/rsvg_internals/src/parsers.rs
+++ b/rsvg_internals/src/parsers.rs
@@ -171,6 +171,33 @@ pub fn integer_optional_integer(s: &str) -> Result<(i32, i32), ValueErrorKind> {
     }
 }
 
+/// Parses a list of identifiers from a `cssparser::Parser`
+///
+/// # Example
+///
+/// ```ignore
+/// let my_boolean = parse_identifiers!(
+///     parser,
+///     "true" => true,
+///     "false" => false,
+/// )?;
+/// ```
+macro_rules! parse_identifiers {
+    ($parser:expr,
+     $($str:expr => $val:expr,)+) => {
+        {
+            let loc = $parser.current_source_location();
+            let token = $parser.next()?;
+
+            match token {
+                $(cssparser::Token::Ident(ref cow) if cow.eq_ignore_ascii_case($str) => Ok($val),)+
+
+                _ => Err(loc.new_unexpected_token_error(token.clone()))
+            }
+        }
+    };
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;