import { BufReader } from "https://deno.land/std@0.177.1/io/buf_reader.ts";
Constructors
Methods
peek()
returns the next n
bytes without advancing the reader. The
bytes stop being valid at the next read call.
When the end of the underlying stream is reached, but there are unread
bytes left in the buffer, those bytes are returned. If there are no bytes
left in the buffer, it returns null
.
If an error is encountered before n
bytes are available, peek()
throws
an error with the partial
property set to a slice of the buffer that
contains the bytes that were available before the error occurred.
reads data into p. It returns the number of bytes read into p. The bytes are taken from at most one Read on the underlying Reader, hence n may be less than len(p). To read exactly len(p) bytes, use io.ReadFull(b, p).
Returns the next byte [0, 255] or null
.
reads exactly p.length
bytes into p
.
If successful, p
is returned.
If the end of the underlying stream has been reached, and there are no more
bytes available in the buffer, readFull()
returns null
instead.
An error is thrown if some bytes could be read, but not enough to fill p
entirely before the underlying stream reported an error or EOF. Any error
thrown will have a partial
property that indicates the slice of the
buffer that has been successfully filled with data.
Ported from https://golang.org/pkg/io/#ReadFull
readLine()
is a low-level line-reading primitive. Most callers should
use readString('\n')
instead or use a Scanner.
readLine()
tries to return a single line, not including the end-of-line
bytes. If the line was too long for the buffer then more
is set and the
beginning of the line is returned. The rest of the line will be returned
from future calls. more
will be false when returning the last fragment
of the line. The returned buffer is only valid until the next call to
readLine()
.
The text returned from ReadLine does not include the line end ("\r\n" or "\n").
When the end of the underlying stream is reached, the final bytes in the
stream are returned. No indication or error is given if the input ends
without a final line end. When there are no more trailing bytes to read,
readLine()
returns null
.
Calling unreadByte()
after readLine()
will always unread the last byte
read (possibly a character belonging to the line end) even if that byte is
not part of the line returned by readLine()
.
readSlice()
reads until the first occurrence of delim
in the input,
returning a slice pointing at the bytes in the buffer. The bytes stop
being valid at the next read.
If readSlice()
encounters an error before finding a delimiter, or the
buffer fills without finding a delimiter, it throws an error with a
partial
property that contains the entire buffer.
If readSlice()
encounters the end of the underlying stream and there are
any bytes left in the buffer, the rest of the buffer is returned. In other
words, EOF is always treated as a delimiter. Once the buffer is empty,
it returns null
.
Because the data returned from readSlice()
will be overwritten by the
next I/O operation, most clients should use readString()
instead.
readString() reads until the first occurrence of delim in the input,
returning a string containing the data up to and including the delimiter.
If ReadString encounters an error before finding a delimiter,
it returns the data read before the error and the error itself
(often null
).
ReadString returns err != nil if and only if the returned data does not end
in delim.
For simple uses, a Scanner may be more convenient.
Discards any buffered data, resets all state, and switches the buffered reader to read from r.
Returns the size of the underlying buffer in bytes.