Add benchmark for pair.line_col vs position.line_cole

grammars/Cargo.toml

@@ -1,29 +1,29 @@
 [package]
-name = "pest_grammars"
+authors = ["Dragoș Tiselice <dragostiselice@gmail.com>"]
+categories = ["parsing"]
 description = "pest popular grammar implementations"
-version = "2.5.2"
+documentation = "https://docs.rs/pest"
 edition = "2021"
-authors = ["Dragoș Tiselice <dragostiselice@gmail.com>"]
 homepage = "https://pest.rs/"
-repository = "https://github.com/pest-parser/pest"
-documentation = "https://docs.rs/pest"
 keywords = ["pest", "parser", "peg", "grammar"]
-categories = ["parsing"]
 license = "MIT/Apache-2.0"
+name = "pest_grammars"
 readme = "_README.md"
+repository = "https://github.com/pest-parser/pest"
 rust-version = "1.56"
+version = "2.5.2"
 
 [dependencies]
-pest = { path = "../pest", version = "2.5.2" }
-pest_derive = { path = "../derive", version = "2.5.2" }
+pest = {path = "../pest", version = "2.5.2", features = ["fast-line-col"]}
+pest_derive = {path = "../derive", version = "2.5.2"}
 
 [dev-dependencies]
 criterion = "0.3"
 
 [[bench]]
-name = "json"
 harness = false
+name = "json"
 
 [[bench]]
+harness = false
 name = "http"
-harness = false

grammars/benches/json.rs

@@ -62,10 +62,22 @@ fn line_col_benchmark(c: &mut Criterion) {
 
     file.read_to_string(&mut data).unwrap();
     let pairs = autocorrect::JsonParser::parse(autocorrect::Rule::item, &data).unwrap();
-    let last_pair = pairs.last().unwrap();
-    c.bench_function("line col", |b| {
+
+    c.bench_function("pair.line_col", |b| {
+        b.iter(|| {
+            let mut pairs = pairs.clone();
+            for _ in 0..500 {
+                pairs.next().unwrap().line_col();
+            }
+        })
+    });
+
+    c.bench_function("position.line_col", |b| {
         b.iter(|| {
-            last_pair.line_col();
+            let mut pairs = pairs.clone();
+            for _ in 0..500 {
+                pairs.next().unwrap().as_span().start_pos().line_col();
+            }
         });
     });
 }

pest/src/position.rs

@@ -116,6 +116,10 @@ impl<'i> Position<'i> {
 
     /// Returns the line and column number of this `Position`.
     ///
+    /// This is an O(n) operation, where n is the number of lines in the input.
+    /// You better use `pair.line_col()` instead.
+    ///
+    ///
     /// # Examples
     ///
     /// ```