Read a string from Stream, providing functionality similar to
split_string/4.
The predicate performs the following steps:
- Skip all characters that match PadChars
- Read up to a character that matches SepChars or end of
file
- Discard trailing characters that match PadChars from the
collected input
- Unify String with a string created from the input and
Sep with the separator character read. If input was
terminated by the end of the input, Sep is unified with -1.
The predicate read_string/5
called repeatedly on an input until
Sep is -1 (end of file) is equivalent to reading the entire
file into a string and calling split_string/4,
provided that SepChars and PadChars are not partially
overlapping.157Behaviour that
is fully compatible would require unlimited look-ahead.
Below are some examples:
% Read a line
read_string(Input, "\n", "\r", End, String)
% Read a line, stripping leading and trailing white space
read_string(Input, "\n", "\r\t ", End, String)
% Read upto , or ), unifying End with 0', or 0')
read_string(Input, ",)", "\t ", End, String)
