add StringView::unsafe_make

Author: hackwaly

string/string.mbti

@@ -23,6 +23,7 @@ impl StringView {
   op_as_view(Self, start~ : Int = .., end? : Int) -> Self
   op_get(Self, Int) -> Char
   rev_get(Self, Int) -> Char
+  unsafe_make(String, Int, Int) -> Self
 }
 impl Show for StringView
 

string/view.mbt

@@ -292,6 +292,39 @@ pub fn View::op_as_view(self : View, start~ : Int = 0, end? : Int) -> View {
   { str: self.str, start, end }
 }
 
+///|
+/// Creates a new `StringView` without checking if the indices are valid UTF-16
+/// boundaries.
+///
+/// Parameters:
+///
+/// * `string` : The source string to create a view from.
+/// * `start` : The starting UTF-16 code unit index into the string.
+/// * `end` : The ending UTF-16 code unit index into the string (exclusive).
+///
+/// Returns a new `StringView` instance that provides a view into the specified
+/// portion of the string.
+///
+/// Example:
+///
+/// ```moonbit
+/// ///|
+/// test "StringView::unsafe_make" {
+///   let str = "Hello🌍"
+///   let view = StringView::unsafe_make(str, 0, 5)
+///   inspect!(view, content="Hello")
+/// }
+/// ```
+///
+/// @alert unsafe "This function does not check if the indices are valid UTF-16 boundaries. Use String::op_as\_view for safe string view creation."
+pub fn View::unsafe_make(
+  str : String,
+  start : Int,
+  end : Int
+) -> StringView {
+  { str, start, end }
+}
+
 ///|
 /// Return the character at the given index.
 ///