Bratko, Chapter 6: Input and Output

- basic file input
  - see(Filename) changes current input stream to Filename
    - see(user) changes current input stream to user (keyboard)
  - 'seen' closes the current input file
  - 'end_of_file' read when at end of file
- basic file output
  - tell(Filename) changes current output stream to Filename
    - tell(user) changes current output stream to user (screen)
  - 'told' closes the current output file
- term i/o
  - read(X)
    - X matched with next term T in input stream
    - read fails if match (X = T) fails
    - read does not backtrack on failure, attempting to read more terms
    - T must be a valid term followed by a period and a space or return
    - X = end_of_file when attempting to read passed end of file
  - write(X)
    - writes X to standard output
    - use 'ttyflush' after write if nothing appears immediately
  - tab(N) causes N spaces to be output
  - 'nl' outputs a new line (no arguments)
  - examples
    - calculator
    - displaying lists (p150)
    - formatting terms (fig6.3)
    - processing a file of terms (p152)
    - cat
- character i/o
  - get(C) reads a single character, ignoring whitespace
  - get0(C) reads a single character, including whitespace
  - put(C) outputs character whose ASCII code is C
  - 0 <= C <= 127, (C = -1) ==> EOF
  - examples
    - ascii converter
    - cat2
- format ???
- constructing and decomposing atoms
  - name(A,L) is true if L is the list of ASCII codes of the chars in A
  - examples
    - sentence to list [Fig 6.4]
    - plurals [Exer 6.5] + special cases
- reading programs
  - consult(F)
    - reads in clauses from file F
    - another consult adds clauses to end of current clauses, even if
      clauses have the same name as previously consulted clauses
  - reconsult(F)
    - same as consult, but for any clauses in F already existing, the
      existing clauses are replaced by the new clauses in F

- HW2
  - blocks-world state visualizer
  - monkey-bananas state visualizer
  - Exercise 6.6