## Split a string into its constituent grapheme clusters.
##
## This function breaks a string into its individual [grapheme clusters](https://stackoverflow.com/a/27331885/4200103),
## returning them as a list of strings. This is useful for working with text that
## contains complex characters, such as emojis or combined characters.
##
## Examples:
## ```
## expect Str.graphemes "Roc" == ["R", "o", "c"]
## expect Str.graphemes "नमस्ते" == ["न", "म", "स", "्", "त", "े"]
## expect Str.graphemes "👩‍👩‍👦‍👦" == ["👩", "‍", "👩", "‍", "👦", "‍", "👦"]
## ```
##
## Note that the "👩‍👩‍👦‍👦" example consists of 7 grapheme clusters, although it visually
## appears as a single glyph. This is because it uses an emoji modifier sequence.
graphemes : Str -> List Str

## Encode a range of a [List] of [U8] UTF-8 [code units](https://unicode.org/glossary/#code_unit)
## into a [Str]. The range is specified by a `start` index and a `count` of elements to encode.
##
## Returns `Err OutOfBounds` if the specified range exceeds the list's length.
## Returns `Err BadUtf8` if the given bytes within the specified range are invalid UTF-8.
## Returns `Ok ""` when given `[]` or a `count` of 0.
##
## Example:
## ```
## expect Str.toUtf8 "Hi there!" |> Str.fromUtf8Range { start : 0, count : 2 } == Ok "Hi"
## expect Str.toUtf8 "Hello, Roc!" |> Str.fromUtf8Range { start : 0, count : 0 } == Ok ""
## expect Str.toUtf8 "Hello, Roc!" |> Str.fromUtf8Range { start : 7, count : 3 } == Ok "Roc"
## expect Str.toUtf8 "Hello, Roc!" |> Str.fromUtf8Range { start : 12, count : 2 } |> Result.isErr
## ```
fromUtf8Range : List U8, { start : Nat, count : Nat } -> Result Str [BadUtf8 Utf8ByteProblem Nat, OutOfBounds]