diff options
| -rw-r--r-- | src/gleam/utf_codepoint.gleam | 20 | ||||
| -rw-r--r-- | test/utf_codepoint_test.gleam | 16 |
2 files changed, 36 insertions, 0 deletions
diff --git a/src/gleam/utf_codepoint.gleam b/src/gleam/utf_codepoint.gleam new file mode 100644 index 0000000..2c3cb04 --- /dev/null +++ b/src/gleam/utf_codepoint.gleam @@ -0,0 +1,20 @@ +import gleam/result + +pub type UtfCodepoint = UtfCodepoint + +pub type Error { + Invalid +} + +external fn int_to_utf8_codepoint(Int) -> UtfCodepoint = + "gleam_stdlib" "identity" + +pub fn from_int(value: Int) -> Result(UtfCodepoint, Error) { + case value { + i if i > 1114111 -> Error(Invalid) + i if i == 65534 -> Error(Invalid) + i if i == 65535 -> Error(Invalid) + i if i >= 55296 && i <= 57343 -> Error(Invalid) + i -> Ok(int_to_utf8_codepoint(i)) + } +} diff --git a/test/utf_codepoint_test.gleam b/test/utf_codepoint_test.gleam new file mode 100644 index 0000000..a3747ba --- /dev/null +++ b/test/utf_codepoint_test.gleam @@ -0,0 +1,16 @@ +import gleam/should +import gleam/utf_codepoint + +pub fn from_int_test() { + utf_codepoint.from_int(1114444) + |> should.be_error + + utf_codepoint.from_int(65534) + |> should.be_error + + utf_codepoint.from_int(55296) + |> should.be_error + + assert Ok(snake) = utf_codepoint.from_int(128013) + should.equal(<<snake:utf8_codepoint>>, <<"🐍":utf8>>) +} |