The Base64 structure

The Base64 structure provides support for Base-64 encoding/decoding as specified by RFC 4648.

Synopsis

signature BASE64
structure Base64 : BASE64

Interface

val isBase64 : char -> bool

val encode : Word8Vector.vector -> string
val encodeSlice : Word8VectorSlice.slice -> string

exception Incomplete

exception Invalid of (int * char)

val decode : string -> Word8Vector.vector
val decodeSlice : substring -> Word8Vector.vector

val decodeStrict : string -> Word8Vector.vector
val decodeSliceStrict : substring -> Word8Vector.vector

Description

val isBase64 : char -> bool

isBase64 c returns true if the character c is in the Base-64 alphabet (i.e., a letter, digit, or a slash or plus character). Note that the padding character (the equals sign) is not considered to be in the alphabet.

val encode : Word8Vector.vector -> string

encode bv returns a string that is the Base-64 encoding of the byte vector bv.

val encodeSlice : Word8VectorSlice.slice -> string

encode bvs returns a string that is the Base-64 encoding of the byte-vector slice bvs.

exception Incomplete

This exception is raised by the decoding functions if a Base-64 string does not end in a complete encoding quantum (i.e., four characters including padding characters).

exception Invalid of (int * char)

This exception is raised by the decoding functions if an invalid Base-64 character is encountered. The int is the position of the character and the char is the invalid character.

val decode : string -> Word8Vector.vector

decode s returns the result of decoding the Base-64 string s. This function ignores whitespace (e.g., line breaks), but will raise the Incomplete exception if the last quantum is incomplete.

val decodeSlice : substring -> Word8Vector.vector

decode ss returns the result of decoding the Base-64 substring ss. This function ignores whitespace (e.g., line breaks), but will raise the Incomplete exception if the last quantum is incomplete.

val decodeStrict : string -> Word8Vector.vector

decodeStrict s returns the result of decoding the Base-64 string s. The string s maust only contain valid Base-64 characters, otherwise the Invalid exception is raised. This function will also raise the Incomplete exception if the last quantum is incomplete.

val decodeSliceStrict : substring -> Word8Vector.vector

decode ss returns the result of decoding the Base-64 substring ss. The string s maust only contain valid Base-64 characters, otherwise the Invalid exception is raised. This function will also raise the Incomplete exception if the last quantum is incomplete.

See Also

The Util Library