Improve attrs_from_sgr_parameters performance

Instead of collecting all the data into the vector just dispatch it
right away avoiding allocations.

3 files changed, 10 insertions, 15 deletions

diff --git a/src/ansi.rs b/src/ansi.rs
index 59b17e6..8cac26d 100644
--- a/src/ansi.rs
+++ b/src/ansi.rs
@@ -1620,12 +1620,7 @@ where
                 if params.is_empty() {
                     handler.terminal_attribute(Attr::Reset);
                 } else {
-                    for attr in attrs_from_sgr_parameters(&mut params_iter) {
-                        match attr {
-                            Some(attr) => handler.terminal_attribute(attr),
-                            None => unhandled!(),
-                        }
-                    }
+                    attrs_from_sgr_parameters(*handler, &mut params_iter);
                 }
             },
             ('m', [b'>']) => {
@@ -1769,9 +1764,7 @@ where
 }
 
 #[inline]
-fn attrs_from_sgr_parameters(params: &mut ParamsIter<'_>) -> Vec<Option<Attr>> {
-    let mut attrs = Vec::with_capacity(params.size_hint().0);
-
+fn attrs_from_sgr_parameters<H: Handler>(handler: &mut H, params: &mut ParamsIter<'_>) {
     while let Some(param) = params.next() {
         let attr = match param {
             [0] => Some(Attr::Reset),
@@ -1851,10 +1844,12 @@ fn attrs_from_sgr_parameters(params: &mut ParamsIter<'_>) -> Vec<Option<Attr>> {
             [107] => Some(Attr::Background(Color::Named(NamedColor::BrightWhite))),
             _ => None,
         };
-        attrs.push(attr);
-    }
 
-    attrs
+        match attr {
+            Some(attr) => handler.terminal_attribute(attr),
+            None => continue,
+        }
+    }
 }
 
 /// Handle colon separated rgb color escape sequence.
diff --git a/src/definitions.rs b/src/definitions.rs
index 218c1eb..568a8a8 100644
--- a/src/definitions.rs
+++ b/src/definitions.rs
@@ -57,9 +57,9 @@ pub fn unpack(delta: u8) -> (State, Action) {
     unsafe {
         (
             // State is stored in bottom 4 bits
-            mem::transmute(delta & 0x0f),
+            mem::transmute::<u8, State>(delta & 0x0f),
             // Action is stored in top 4 bits
-            mem::transmute(delta >> 4),
+            mem::transmute::<u8, Action>(delta >> 4),
         )
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 31e2a31..0f12902 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -56,7 +56,7 @@ const MAX_OSC_RAW: usize = 1024;
 
 struct VtUtf8Receiver<'a, P: Perform>(&'a mut P, &'a mut State);
 
-impl<'a, P: Perform> utf8::Receiver for VtUtf8Receiver<'a, P> {
+impl<P: Perform> utf8::Receiver for VtUtf8Receiver<'_, P> {
     fn codepoint(&mut self, c: char) {
         self.0.print(c);
         *self.1 = State::Ground;