From 1713a4424b2c3f54363f02f25d6dea216c148951 Mon Sep 17 00:00:00 2001
From: Markus Westerlind <marwes91@gmail.com>
Date: Sat, 26 Jan 2019 22:38:17 +0100
Subject: [PATCH] perf: Optimized definition_name for the non-`:` case

---
 base/src/symbol.rs   | 40 +++++++++++++++++++++++++++++++++++-----
 vm/src/primitives.rs |  4 ++--
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/base/src/symbol.rs b/base/src/symbol.rs
index 74deaf1f65..f3e545bf86 100644
--- a/base/src/symbol.rs
+++ b/base/src/symbol.rs
@@ -288,12 +288,15 @@ impl Name {
     }
 
     pub fn as_pretty_str(&self) -> &str {
-        let name = &self.0;
-        name.split(':').next().unwrap_or(name)
+        Self::strip_position_suffix(&self.0)
     }
 
     pub fn as_str(&self) -> &str {
-        debug_assert!(!self.0.contains(':'), "Did you mean to call as_pretty_str?");
+        debug_assert!(
+            !self.0.contains(':'),
+            "Did you mean to call as_pretty_str?: {}",
+            &self.0
+        );
         &self.0
     }
 
@@ -318,8 +321,24 @@ impl Name {
     }
 
     pub fn definition_name(&self) -> &str {
-        let name = self.0.trim_start_matches('@');
-        name.split(':').next().unwrap_or(name)
+        Self::strip_position_suffix(if self.0.as_bytes().get(0) == Some(&b'@') {
+            &self.0[1..]
+        } else {
+            &self.0
+        })
+    }
+
+    fn strip_position_suffix(name: &str) -> &str {
+        // Strip away a `:1234_56` suffix
+        let x = match name
+            .bytes()
+            .rposition(|b| (b < b'0' || b > b'9') && b != b'_')
+        {
+            Some(i) if name.as_bytes()[i] == b':' => &name[..i],
+            _ => name,
+        };
+
+        x
     }
 }
 
@@ -555,3 +574,14 @@ impl<'a> IdentEnv for SymbolModule<'a> {
         self.symbol(s)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn definition_name() {
+        assert_eq!(Name::new("a:123").definition_name(), "a");
+        assert_eq!(Name::new("a:123_5").definition_name(), "a");
+    }
+}
diff --git a/vm/src/primitives.rs b/vm/src/primitives.rs
index db3afb946b..4fba0ef241 100644
--- a/vm/src/primitives.rs
+++ b/vm/src/primitives.rs
@@ -706,12 +706,12 @@ pub fn load<'vm>(vm: &'vm Thread) -> Result<ExternModule> {
     use self::std;
 
     vm.define_global(
-        "@error",
+        "error",
         primitive::<fn(StdString) -> Pushed<A>>("@error", std::prim::error),
     )?;
 
     vm.define_global(
-        "@string_eq",
+        "string_eq",
         primitive!(2, "@string_eq", <str as PartialEq>::eq),
     )?;