Document comment feature.

README.md

@@ -37,7 +37,7 @@ assert_eq!(eval("1 + 2 + 3"), Ok(Value::from(6)));
 // while `eval_[type]` returns the respective type directly.
 // Both can be used interchangeably.
 assert_eq!(eval_int("1 + 2 + 3"), Ok(6));
-assert_eq!(eval("1 - 2 * 3"), Ok(Value::from(-5)));
+assert_eq!(eval("1 /* inline comments are supported */ - 2 * 3 // as are end-of-line comments"), Ok(Value::from(-5)));
 assert_eq!(eval("1.0 + 2 * 3"), Ok(Value::from(7.0)));
 assert_eq!(eval("true && 4 > 2"), Ok(Value::from(true)));
 ```
@@ -534,6 +534,28 @@ This crate implements `serde::de::Deserialize` for its type `Node` that represen
 The implementation expects a [serde `string`](https://serde.rs/data-model.html) as input.
 Example parsing with [ron format](docs.rs/ron):
 
+### Comments
+
+Evalexpr supports C-style inline comments and end-of-line comments.
+Inline comments are started with a `/*` and terminated with a `*/`.
+End-of-line comments are started with a `//` and terminated with a newline character.
+For example:
+
+```rust
+use evalexpr::*;
+
+assert_eq!(
+    eval(
+        "
+        // input
+        a = 1;  // assignment
+        // output
+        2 * a /* first double a */ + 2 // then add 2"
+    ),
+    Ok(Value::Int(4))
+);
+```
+
 ```rust
 extern crate ron;
 use evalexpr::*;

src/lib.rs

@@ -18,7 +18,7 @@
 //! // while `eval_[type]` returns the respective type directly.
 //! // Both can be used interchangeably.
 //! assert_eq!(eval_int("1 + 2 + 3"), Ok(6));
-//! assert_eq!(eval("1 - 2 * 3"), Ok(Value::from(-5)));
+//! assert_eq!(eval("1 /* inline comments are supported */ - 2 * 3 // as are end-of-line comments"), Ok(Value::from(-5)));
 //! assert_eq!(eval("1.0 + 2 * 3"), Ok(Value::from(7.0)));
 //! assert_eq!(eval("true && 4 > 2"), Ok(Value::from(true)));
 //! ```
@@ -515,6 +515,28 @@
 //! The implementation expects a [serde `string`](https://serde.rs/data-model.html) as input.
 //! Example parsing with [ron format](docs.rs/ron):
 //!
+//! ### Comments
+//!
+//! Evalexpr supports C-style inline comments and end-of-line comments.
+//! Inline comments are started with a `/*` and terminated with a `*/`.
+//! End-of-line comments are started with a `//` and terminated with a newline character.
+//! For example:
+//!
+//! ```rust
+//! use evalexpr::*;
+//!
+//! assert_eq!(
+//!     eval(
+//!         "
+//!         // input
+//!         a = 1;  // assignment
+//!         // output
+//!         2 * a /* first double a */ + 2 // then add 2"
+//!     ),
+//!     Ok(Value::Int(4))
+//! );
+//! ```
+//!
 //! ```rust
 //! # #[cfg(feature = "serde_support")] {
 //! extern crate ron;