class StringInput
include Enumerable
class << self
def new( str )
if block_given?
begin; f = super; yield f
ensure; f.close if f; end
else; super; end
end
alias open new
end
def initialize( str )
@string = str
@pos = 0
@closed = false
@lineno = 0
end
attr_reader :lineno,:string
def inspect
return "#<#{self.class}:#{@closed ? 'closed' : 'open'},src=#{@string[0,30].inspect}>"
end
def close
raise IOError, 'closed stream' if @closed
@pos=nil; @closed=true
end
def closed?; @closed; end
def pos
raise IOError, 'closed stream' if @closed
[@pos, @string.size].min
end
alias tell pos
def rewind; seek(0); end
def pos=(value); seek(value); end
def seek( offset, whence=IO::SEEK_SET )
raise IOError, 'closed stream' if @closed
case whence
when IO::SEEK_SET
@pos=offset
when IO::SEEK_CUR
@pos+=offset
when IO::SEEK_END
@[email protected] - offset
else
raise ArgumentError, "unknown seek flag: #{whence}"
end
@pos = 0 if @pos < 0
@pos = [@pos, @string.size + 1].min
offset
end
def eof?
raise IOError, 'closed stream' if @closed
@pos > @string.size
end
def each( &block )
raise IOError, 'closed stream' if @closed
begin
@string.each(&block)
ensure
@pos = 0
end
end
def gets
raise IOError, 'closed stream' if @closed
if idx = @string.index(?\n, @pos)
idx += 1 # "\n".size
line = @string[ @pos ... idx ]
@pos = idx
@pos += 1 if @pos == @string.size
else
line = @string[ @pos .. -1 ]
@pos = @string.size + 1
end
@lineno += 1
line
end
def getc
raise IOError, 'closed stream' if @closed
ch = @string[@pos]
@pos += 1
@pos += 1 if @pos == @string.size
ch
end
def read( len = nil )
raise IOError, 'closed stream' if @closed
if !len
return nil if eof?
rest = @string[@pos ... @string.size]
@pos = @string.size + 1
return rest
end
str = @string[@pos, len]
@pos += len
@pos += 1 if @pos == @string.size
str
end
def read_all; read(); end
alias sysread read
end
