1 files changed, 79 insertions, 0 deletions
diff --git a/src/lib.rs b/src/lib.rs
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+++ b/src/lib.rs
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+// Copyright (C) 2022 Soni L.
+// SPDX-License-Identifier: 0BSD
+
+//! A replacement for char
+//! ======================
+//!
+//! Because Rust's `char::is_ascii*` family of functions takes `&self`, it's
+//! impossible to use them as patterns. This is inconsistent with the rest of
+//! `char::is_*`, which takes `self`.
+//!
+//! This crate provides `char`-taking variants of the `is_ascii*` family of
+//! functions.
+//!
+//! # Examples
+//!
+//! This works:
+//!
+//! ```rust
+//! "hello".trim_start_matches(char::is_numeric);
+//! ```
+//!
+//! This doesn't:
+//!
+//! ```rust compile_fail
+//! "hello".trim_start_matches(char::is_ascii_digit);
+//! ```
+//!
+//! This crate provides an alternative:
+//!
+//! ```rust
+//! "hello".trim_start_matches(charx::is_ascii_digit);
+//! ```
+
+macro_rules! charx_fn {
+    ($name:ident) => {
+        #[doc=concat!("Same as [`char::", stringify!($name), "`] but takes `char` instead of `&char`.")]
+        ///
+        /// # Examples
+        ///
+        /// This doesn't compile:
+        ///
+        /// ```rust compile_fail
+        #[doc=concat!("\"hello\".trim_start_matches(char::", stringify!($name), ");")]
+        /// ```
+        ///
+        /// But this does:
+        ///
+        /// ```rust
+        #[doc=concat!("\"hello\".trim_start_matches(charx::", stringify!($name), ");")]
+        /// ```
+        #[inline(always)]
+        pub fn $name(c: char) -> bool {
+            char::$name(&c)
+        }
+        mod $name {
+            #[test]
+            fn test() {
+                for c in '\0'..='\u{10FFFF}' {
+                    assert_eq!(char::$name(&c), crate::$name(c));
+                }
+            }
+        }
+    };
+    ($($name:ident)*) => {
+        $(charx_fn!($name);)*
+    };
+}
+
+charx_fn!(is_ascii
+is_ascii_alphabetic
+is_ascii_alphanumeric
+is_ascii_control
+is_ascii_digit
+is_ascii_graphic
+is_ascii_hexdigit
+is_ascii_lowercase
+is_ascii_punctuation
+is_ascii_uppercase
+is_ascii_whitespace);