/
base.gleam
41 lines (35 loc) 路 1.23 KB
/
base.gleam
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import gleam/bit_string.{BitString}
import gleam/string
external fn erl_encode64(BitString) -> String =
"base64" "encode"
external fn erl_decode64(String) -> Result(BitString, Nil) =
"gleam_stdlib" "base_decode64"
/// Encodes a BitString into a base 64 encoded string.
pub fn encode64(input: BitString, padding: Bool) -> String {
let encoded = erl_encode64(input)
case padding {
True -> encoded
False -> string.replace(encoded, "=", "")
}
}
/// Decodes a base 64 encoded string into a BitString.
pub fn decode64(encoded: String) -> Result(BitString, Nil) {
let padded = case bit_string.byte_size(bit_string.from_string(encoded)) % 4 {
0 -> encoded
n -> string.append(encoded, string.repeat("=", 4 - n))
}
erl_decode64(padded)
}
/// Encodes a BitString into a base 64 encoded string with URL and filename safe alphabet.
pub fn url_encode64(input: BitString, padding: Bool) -> String {
encode64(input, padding)
|> string.replace("+", "-")
|> string.replace("/", "_")
}
/// Decodes a base 64 encoded string with URL and filename safe alphabet into a BitString.
pub fn url_decode64(encoded: String) -> Result(BitString, Nil) {
encoded
|> string.replace("-", "+")
|> string.replace("_", "/")
|> decode64()
}