Iterate over the lines in a file.
Returns lines without trailing line breaks. Advances the file cursor to the end of each line returned from next.
This class buffers the file contents to accumulate full lines. If the file does not contain linebreaks, the whole file content is read and buffered, which might exceed memory resources. Take care.
class ref FileLines is Iterator[String iso^] ref
Create a FileLines instance on a given file.
This instance returns lines from the position of the given file at the time this constructor is called. Later manipulation of the file position is not accounted for. As a result iterating with this class will always return the full file content without gaps or repeated lines.
min_read_size determines the minimum amount of bytes to read from the file in one go. This class keeps track of the line lengths in the current file and uses the length of the last line as amount of bytes to read next, but it will never read less than min_read_size.
new ref create( file: File ref, min_read_size: USize val = 256) : FileLines ref^
fun ref has_next() : Bool val
Returns the next line in the file.
fun ref next() : String iso^ ?
fun ref _read_line() : String iso^ ?
read from file and fill the reader-buffer.
Returns true if data could be read from the file.
After a successful reading operation _buffer_cursor is updated.
fun ref _fill_buffer() : Bool val
fun ref _read_last_line() : String iso^ ?
fun ref _inc_public_file_cursor( amount: USize val) : None val
© 2016-2018, The Pony Developers
© 2014-2015, Causality Ltd.
Licensed under the BSD 2-Clause License.
https://stdlib.ponylang.io/files-FileLines