From 4093727dcbc5ba272efd60d074bcaae584fe08b1 Mon Sep 17 00:00:00 2001
From: Stephen Chung <schungx@live.com>
Date: Thu, 17 Jun 2021 13:31:58 +0800
Subject: [PATCH] New string functions.

---
 CHANGELOG.md                |  1 +
 src/packages/string_more.rs | 46 +++++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8e3064f..cfc3b096 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@ New features
 * The `bits` method of an integer can be used to iterate through its bits.
 * New `$bool$`, `$int$`, `$float$` and `$string$` expression types for custom syntax.
 * New methods `to_hex`, `to_octal` and `to_binary` for integer numbers.
+* New methods `to_upper`, `to_lower`, `make_upper`, `make_lower` for strings/characters.
 
 
 Version 0.20.2
diff --git a/src/packages/string_more.rs b/src/packages/string_more.rs
index 86694e84..2dc9cfa3 100644
--- a/src/packages/string_more.rs
+++ b/src/packages/string_more.rs
@@ -100,6 +100,52 @@ mod string_functions {
         }
     }
 
+    pub fn to_upper(string: &str) -> ImmutableString {
+        string.to_uppercase().into()
+    }
+    pub fn make_upper(string: &mut ImmutableString) {
+        *string = to_upper(string);
+    }
+    pub fn to_lower(string: &str) -> ImmutableString {
+        string.to_lowercase().into()
+    }
+    pub fn make_lower(string: &mut ImmutableString) {
+        *string = to_lower(string);
+    }
+
+    #[rhai_fn(name = "to_upper")]
+    pub fn to_upper_char(character: char) -> char {
+        let mut stream = character.to_uppercase();
+        let ch = stream
+            .next()
+            .expect("never fails because there should be at least one character");
+        if stream.next().is_some() {
+            character
+        } else {
+            ch
+        }
+    }
+    #[rhai_fn(name = "make_upper")]
+    pub fn make_upper_char(character: &mut char) {
+        *character = to_upper_char(*character)
+    }
+    #[rhai_fn(name = "to_lower")]
+    pub fn to_lower_char(character: char) -> char {
+        let mut stream = character.to_lowercase();
+        let ch = stream
+            .next()
+            .expect("never fails because there should be at least one character");
+        if stream.next().is_some() {
+            character
+        } else {
+            ch
+        }
+    }
+    #[rhai_fn(name = "make_lower")]
+    pub fn make_lower_char(character: &mut char) {
+        *character = to_lower_char(*character)
+    }
+
     #[rhai_fn(name = "index_of")]
     pub fn index_of_char_starting_from(string: &str, character: char, start: INT) -> INT {
         let start = if start < 0 {