# Is there something to read.
# This function returns 'false' if there is something to read.
fun eof: Bool is abstract
+
+ # Read the next sequence of non whitespace characters.
+ #
+ # Leading whitespace characters are skipped.
+ # The first whitespace character that follows the result is consumed.
+ #
+ # An empty string is returned if the end of the file or an error is encounter.
+ #
+ # ~~~
+ # var w = new StringReader(" Hello, \n\t World!")
+ # assert w.read_word == "Hello,"
+ # assert w.read_char == '\n'.ascii
+ # assert w.read_word == "World!"
+ # assert w.read_word == ""
+ # ~~~
+ #
+ # `Char::is_whitespace` determines what is a whitespace.
+ fun read_word: String
+ do
+ var buf = new FlatBuffer
+ var c = read_nonwhitespace
+ if c > 0 then
+ buf.add(c.ascii)
+ while not eof do
+ c = read_char
+ if c < 0 then break
+ var a = c.ascii
+ if a.is_whitespace then break
+ buf.add(a)
+ end
+ end
+ var res = buf.to_s
+ return res
+ end
+
+ # Skip whitespace characters (if any) then return the following non-whitespace character.
+ #
+ # Returns the code point of the character.
+ # Return -1 on end of file or error.
+ #
+ # In fact, this method works like `read_char` except it skips whitespace.
+ #
+ # ~~~
+ # var w = new StringReader(" \nab\tc")
+ # assert w.read_nonwhitespace == 'a'.ascii
+ # assert w.read_nonwhitespace == 'b'.ascii
+ # assert w.read_nonwhitespace == 'c'.ascii
+ # assert w.read_nonwhitespace == -1
+ # ~~~
+ #
+ # `Char::is_whitespace` determines what is a whitespace.
+ fun read_nonwhitespace: Int
+ do
+ var c = -1
+ while not eof do
+ c = read_char
+ if c < 0 or not c.ascii.is_whitespace then break
+ end
+ return c
+ end
end
# Iterator returned by `Reader::each_line`.