Libraries
Class BufferedReader
A reader wrapper that buffers the content offered by a reader.
Constructors
constructor reader_/Reader
Methods
Whether n bytes are available in the internal buffer.
This function will not call read on the underlying reader, so it only tells you the bytes that can be read without a read operation that might block.
Reads and buffers until the end of the reader.
Amount of buffered data.
This function will not call read on the underlying reader, so it only tells you the bytes that can be read without a read operation that might block.
Tries to buffer n bytes, and returns whether it was able to.
Clears any buffered data.
Ensures that at least n bytes are available.
Errors
At least n bytes must be available in the underlying reader. Use can-ensure if a non-throwing version is necessary.
Searches forwards for the byte.
Consumes no bytes.
Returns the index of the first occurrence of the byte.
Returns null otherwise.
Searches forwards for the byte.
Consumes no bytes.
Returns the index of the first occurrence of the byte.
Returns -1 otherwise.
Searches forwards for the index of the byte.
Consumes no bytes.
Returns the index of the first occurrence of the byte.
Throws if the byte is not found.
Whether this object is equal to the other.
Inheritance
Classes overwrite this operator to get an equality specific to their needs. Equality operators often compare the type and field contents. For example:
class Pin:
number/int
constructor .number:
operator == other:
if other is not Pin: return false
return number == other.number
A class doesn't have to follow the above format, but it must keep the operator in sync with any
hash-code method. That is, if a class has a hash-code member, then the equality and hash-code must agree. If two instances are equal (a == b), then their hash codes must also be equal (a.hash-code == b.hash-code).Peeks the first n bytes and converts them to a string.
Errors
The peeked bytes must be convertible to a UTF8 string.
At least n bytes must be available.
Examples
class MyReader implements Reader:
read -> ByteArray?: return "hellø".to_byte_array
main:
reader := BufferedReader MyReader
print
reader.peek_string 6 // >> Hellø
print
reader.peek_string 5 // >> Error!
Reads from the reader.
The read bytes are consumed.
If max-size is specified the returned byte array will never be larger than that size, but it may be smaller, even if there is more data available from the underlying reader. Use read-bytes to read exactly n bytes.
Returns null if the reader is at the end.
Reads the first byte.
The read byte is consumed.
Errors
At least 1 byte must be available.
Reads the first n bytes from the reader.
The read bytes are consumed.
If you want to read either n bytes, if they are available, or the maximum number of available bytes otherwise, use the following code:
read_exactly_or_drain reader/BufferedReader n/int -> ByteArray?:
if can_ensure n: return reader.read_bytes n
reader.buffer_all
if reader.buffered == 0: return null
return reader.read_bytes reader.buffered
Reads the bytes before the delimiter.
The read bytes and the delimiter are consumed.
Errors
The delimiter must be available.
Reads a line as a string.
Lines are terminated by a newline character (
'\n') except for the final line.Carriage returns (
'\r') are removed from lines terminated by '\r\n'.Reads the first n bytes as a string.
The read bytes are consumed.
Errors
The read bytes must be convertible to a UTF8 string.
At least n bytes must be available.
Examples
class MyReader implements Reader:
read -> ByteArray?: return "hellø".to_byte_array
main:
reader := BufferedReader MyReader
print
reader.read_string 6 // >> Hellø
print
reader.read_string 5 // >> Error!
Reads at most max-size bytes as a string.
The read bytes are consumed.
Note that this method is different from read followed by to_string as it ensures that the data is split into valid UTF-8 chunks.
If max-size is specified the returned string will never be larger than that size (in bytes), but it may be smaller, even if there is more data available from the underlying reader.
Returns null if the stream has ended.
Errors
The read bytes must be convertible to a legal UTF8 string, but this method will read a number of bytes such that legal UTF-8 characters are not chopped up.
May throw an end-of-stream exception if the stream ends in the middle of a malformed UTF-8 character.
Instead of returning a zero length string it throws an exception. This can happen if max-size is less than 4 bytes and the next thing is a UTF-8 character that is coded in more bytes than were requested. This also means max-size should never be zero.
Reads the string before the delimiter.
The read bytes and the delimiter are consumed.
Errors
The delimiter must be available.
Reads up to the max-size amount of bytes from the reader.
The read bytes are consumed.
Errors
At least 1 byte must be available.
Skips n bytes.
Errors
At least n bytes must be available.
Stringifies this object.
Inheritance
Objects that need a human-friendly string representation should overwrite this method. The default string is based on the internal class-ID.
The bytes in value are prepended to the BufferedReader.
These will be the first bytes to be read in subsequent read operations. This takes ownership of value so it is kept alive and its contents should not be modified after being given to the BufferedReader.