diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
new file mode 100644
index 00000000..df310705
--- /dev/null
+++ b/.github/workflows/benchmark.yml
@@ -0,0 +1,29 @@
+name: Benchmark
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  benchmark:
+    name: Run Rust benchmark
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: rustup toolchain update nightly && rustup default nightly
+      - name: Run benchmark
+        run: cargo +nightly bench | tee output.txt
+      - name: Store benchmark result
+        uses: rhysd/github-action-benchmark@v1
+        with:
+          name: Rust Benchmark
+          tool: 'cargo'
+          output-file-path: output.txt
+          # Use personal access token instead of GITHUB_TOKEN due to https://github.community/t5/GitHub-Actions/Github-action-not-triggering-gh-pages-upon-push/td-p/26869/highlight/false
+          github-token: ${{ secrets.RHAI }}
+          auto-push: true
+          # Show alert with commit comment on detecting possible performance regression
+          alert-threshold: '200%'
+          comment-on-alert: true
+          fail-on-alert: true
+          alert-comment-cc-users: '@schungx'
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 03e69ede..01b165a7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -3,8 +3,8 @@ name: Build
 on:
   push:
     branches:
+      - main
       - master
-      - v1.3-fixes
   pull_request: {}
 
 jobs:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 80fc04b2..6987d52e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,13 @@ Bug fixes
 ---------
 
 * Variables introduced inside `try` blocks are now properly cleaned up upon an exception.
+* Off-by-one error in character positions after a comment line is now fixed.
+
+Enhancements
+------------
+
+* `rhai-repl` tool has a few more commands, such as `strict` to turn on/off _Strict Variables Mode_ and `optimize` to turn on/off script optimization.
+* Default features for dependencies (such as `ahash/std` and `num-traits/std`) are no longer required.
 
 
 Version 1.4.1
diff --git a/Cargo.toml b/Cargo.toml
index 006c67bf..81d16837 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,7 +26,7 @@ rhai_codegen = { version = "1.2", path = "codegen", default-features = false }
 serde_bytes = "0.11"
 
 [features]
-default = ["ahash/std", "num-traits/std"]
+default = []
 unchecked = []                  # unchecked arithmetic
 sync = []                       # restrict to only types that implement Send + Sync
 no_position = []                # do not track position in the parser
diff --git a/no_std/no_std_test/src/main.rs b/no_std/no_std_test/src/main.rs
index 3db95447..621029ee 100644
--- a/no_std/no_std_test/src/main.rs
+++ b/no_std/no_std_test/src/main.rs
@@ -14,7 +14,7 @@ static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
 #[cfg(all(windows, target_env = "msvc"))]
 #[link(name = "msvcrt")]
 #[link(name = "libcmt")]
-extern {}
+extern "C" {}
 
 use rhai::{Engine, INT};
 
@@ -39,11 +39,17 @@ extern "C" fn rust_begin_panic(_: &core::panic::PanicInfo) -> ! {
     core::intrinsics::abort();
 }
 
-#[lang = "eh_personality"]
-extern "C" fn eh_personality() {}
+#[no_mangle]
+extern "C" fn _rust_eh_personality() {}
+
+#[no_mangle]
+extern "C" fn rust_eh_personality() {}
 
 #[no_mangle]
 extern "C" fn rust_eh_register_frames() {}
 
 #[no_mangle]
 extern "C" fn rust_eh_unregister_frames() {}
+
+#[no_mangle]
+extern "C" fn _Unwind_Resume() {}
diff --git a/src/ast/expr.rs b/src/ast/expr.rs
index b7cb4a52..d2256c5b 100644
--- a/src/ast/expr.rs
+++ b/src/ast/expr.rs
@@ -21,7 +21,7 @@ use std::{
 use std::str::FromStr;
 
 #[cfg(not(feature = "no_float"))]
-use num_traits::Float;
+use num_traits::float::FloatCore as Float;
 
 /// _(internals)_ A binary expression.
 /// Exported under the `internals` feature only.
@@ -646,15 +646,14 @@ impl Expr {
             | Self::Variable(_, pos, _)
             | Self::Stack(_, pos)
             | Self::FnCall(_, pos)
+            | Self::Index(_, _, pos)
             | Self::Custom(_, pos)
             | Self::InterpolatedString(_, pos) => *pos,
 
             Self::Property(x) => (x.2).1,
             Self::Stmt(x) => x.position(),
 
-            Self::And(x, _) | Self::Or(x, _) | Self::Dot(x, _, _) | Self::Index(x, _, _) => {
-                x.lhs.position()
-            }
+            Self::And(x, _) | Self::Or(x, _) | Self::Dot(x, _, _) => x.lhs.position(),
         }
     }
     /// Override the [position][Position] of the expression.
diff --git a/src/bin/rhai-repl.rs b/src/bin/rhai-repl.rs
index 1b77f562..2169b642 100644
--- a/src/bin/rhai-repl.rs
+++ b/src/bin/rhai-repl.rs
@@ -47,6 +47,8 @@ fn print_help() {
     println!("quit, exit => quit");
     println!("scope      => print all variables in the scope");
     println!("strict     => toggle on/off Strict Variables Mode");
+    #[cfg(not(feature = "no_optimize"))]
+    println!("optimize   => toggle on/off script optimization");
     #[cfg(feature = "metadata")]
     println!("functions  => print all functions defined");
     #[cfg(feature = "metadata")]
@@ -85,7 +87,9 @@ fn main() {
     let title = format!("Rhai REPL tool (version {})", env!("CARGO_PKG_VERSION"));
     println!("{}", title);
     println!("{0:=<1$}", "", title.len());
-    print_help();
+
+    #[cfg(not(feature = "no_optimize"))]
+    let mut optimize_level = rhai::OptimizationLevel::Simple;
 
     // Initialize scripting engine
     let mut engine = Engine::new();
@@ -196,6 +200,8 @@ fn main() {
     let mut ast_u = AST::empty();
     let mut ast = AST::empty();
 
+    print_help();
+
     'main_loop: loop {
         print!("rhai-repl> ");
         stdout().flush().expect("couldn't flush stdout");
@@ -247,6 +253,18 @@ fn main() {
                 println!("Strict Variables Mode turned ON.");
                 continue;
             }
+            #[cfg(not(feature = "no_optimize"))]
+            "optimize" if optimize_level == rhai::OptimizationLevel::Simple => {
+                optimize_level = rhai::OptimizationLevel::None;
+                println!("Script optimization turned OFF.");
+                continue;
+            }
+            #[cfg(not(feature = "no_optimize"))]
+            "optimize" => {
+                optimize_level = rhai::OptimizationLevel::Simple;
+                println!("Script optimization turned ON.");
+                continue;
+            }
             "scope" => {
                 print_scope(&scope);
                 continue;
@@ -296,7 +314,7 @@ fn main() {
 
                 #[cfg(not(feature = "no_optimize"))]
                 {
-                    ast = engine.optimize_ast(&scope, r, rhai::OptimizationLevel::Simple);
+                    ast = engine.optimize_ast(&scope, r, optimize_level);
                 }
 
                 #[cfg(feature = "no_optimize")]
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index b23c630e..ba6fb045 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -1592,11 +1592,11 @@ fn get_next_token_inner(
                     // `\r - start from next line
                     Some('\r') => {
                         eat_next(stream, pos);
-                        pos.new_line();
                         // `\r\n
                         if let Some('\n') = stream.peek_next() {
                             eat_next(stream, pos);
                         }
+                        pos.new_line();
                     }
                     // `\n - start from next line
                     Some('\n') => {
@@ -1762,11 +1762,11 @@ fn get_next_token_inner(
 
                 while let Some(c) = stream.get_next() {
                     if c == '\r' {
-                        pos.new_line();
                         // \r\n
                         if let Some('\n') = stream.peek_next() {
                             eat_next(stream, pos);
                         }
+                        pos.new_line();
                         break;
                     }
                     if c == '\n' {