Chunk
Chunks are just binary blocks of data.
Declaration
Chunks cannot be declared explicitly; you must use the type constructor and apply one of the following strategies:
_ <- fat.type.Chunk
Chunk(null) # Void -> [] (empty chunk)
Chunk(4) # Number -> [ 0, 0, 0, 0 ] (blank bytes)
Chunk('ABC') # Text -> [ 65, 66, 67 ]
Chunk([ 65, 66, 67 ]) # List/Number -> [ 65, 66, 67 ]
list of numbers are expected to contain valid byte values (0-255), otherwise an error is raised
Manipulating chunks
Concatenation
In FatScript, you can concatenate, or join, two chunks using the + operator. For example:
abCombined = chunkA + chunkB
Chunk selection
Selection allows access to specific parts of a chunk using indices. FatScript supports both positive and negative indices. Positive indices start from the beginning of the chunk (with 0 as the first byte), while negative indices start from the end (-1 is the last byte).
for detailed explanation about the indexing system in FatScript, refer to the section on accessing and selecting items in List
Selecting with one index retrieves a single byte from the chunk (as number). Using a range of bytes, selects a fragment inclusive of both start and end indices, except when using the half-open range operator ..<, which is exclusive on the right-hand side.
Accessing indices outside the valid range will generate an error for individual selections. For range selections, out-of-bounds indices result in an empty chunk.
x3 = Chunk('example')
x3(1) # 120 (ASCII value of 'x')
x3(..2) # new Chunk containing 3 bytes (corresponding to 'exa')
Direct manipulation
starting with version
3.3.0
Mutation in binary data allows changing specific bytes by position.
For example, in ~ chunk = Chunk([ 65, 66, 67 ]), you can modify the last byte with chunk[2] = 68, transforming the data into [ 65, 66, 68 ].
Comparisons
Chunk equality == and inequality != comparisons are supported.