performance comparison: creating HashMap up front

the previous solution:

anki_tag_parse          time:   [1.8401 us 1.8437 us 1.8476 us]

this solution:

anki_tag_parse          time:   [2.2420 us 2.2447 us 2.2477 us]
                        change: [+21.477% +21.770% +22.066%] (p = 0.00 < 0.05)
                        Performance has regressed.

rslib/src/card_rendering/mod.rs

@@ -82,6 +82,33 @@ struct OtherTag<'a> {
     options: HashMap<&'a str, &'a str>,
 }
 
+impl TtsTag<'_> {
+    pub(crate) fn new<'a>(content: &'a str, options: Vec<(&'a str, &'a str)>) -> TtsTag<'a> {
+        let mut options: HashMap<&str, &str> = options.into_iter().collect();
+        let lang = options.remove("lang").unwrap_or_default();
+        let voices = options
+            .remove("voices")
+            .unwrap_or_default()
+            .split(',')
+            .collect();
+        let speed = options
+            .remove("speed")
+            .unwrap_or_default()
+            .parse()
+            .unwrap_or(1.0);
+        let blank = options.remove("cloze_blank");
+
+        TtsTag {
+            content,
+            lang,
+            voices,
+            speed,
+            blank,
+            options,
+        }
+    }
+}
+
 #[cfg(feature = "bench")]
 #[inline]
 pub fn anki_tag_benchmark() {

rslib/src/card_rendering/parser.rs

@@ -1,8 +1,6 @@
 // Copyright: Ankitects Pty Ltd and contributors
 // License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
 
-use std::collections::HashMap;
-
 use nom::{
     branch::alt,
     bytes::complete::{is_not, tag},
@@ -31,34 +29,7 @@ impl<'a> CardNodes<'a> {
 impl<'a> Tag<'a> {
     fn new(name: &'a str, options: Vec<(&'a str, &'a str)>, content: &'a str) -> Self {
         match name {
-            "tts" => {
-                let mut lang = "";
-                let mut voices = vec![];
-                let mut speed = 1.0;
-                let mut blank = None;
-                let mut other_options = HashMap::new();
-
-                for option in options {
-                    match option.0 {
-                        "lang" => lang = option.1,
-                        "voices" => voices = option.1.split(',').collect(),
-                        "speed" => speed = option.1.parse().unwrap_or(1.0),
-                        "cloze_blank" => blank = Some(option.1),
-                        _ => {
-                            other_options.insert(option.0, option.1);
-                        }
-                    }
-                }
-
-                Self::Tts(TtsTag {
-                    content,
-                    lang,
-                    voices,
-                    speed,
-                    blank,
-                    options: other_options,
-                })
-            }
+            "tts" => Self::Tts(TtsTag::new(content, options)),
             _ => Self::Other(OtherTag {
                 name,
                 content,
@@ -162,6 +133,8 @@ fn text_node(s: &str) -> IResult<Node> {
 
 #[cfg(test)]
 mod test {
+    use std::collections::HashMap;
+
     use super::*;
 
     macro_rules! assert_parsed_nodes {