lexer

Lexer := Object clone do(
  inputString := Sequence clone
  current ::= nil
  next ::= nil

  with := method(str, self clone setInputString(str))

  setInputString := method(str,
    inputString = str
    self
  )

  currentIndentationLevel := method(
    indentationLevel := 0
    inputString foreach(c,
      if(c asCharacter == " " or c asCharacter == "\t",
        indentationLevel = indentationLevel + 1
      ,
        break
      )
    )
    indentationLevel
  )

  advance := method(
    setInputString(inputString exSlice(1, inputString size))
  )

  pending := method(inputString at(0) asCharacter)
)%