Info Catalog eintr: beginning-of-buffer eintr: More Complex eintr: optional Exercise

eintr: Second Buffer Related Review

 
 5.4 Review
 ==========
 
 Here is a brief summary of some of the topics covered in this chapter.
 
 ‘or’
      Evaluate each argument in sequence, and return the value of the
      first argument that is not ‘nil’; if none return a value that is
      not ‘nil’, return ‘nil’.  In brief, return the first true value of
      the arguments; return a true value if one _or_ any of the others
      are true.
 
 ‘and’
      Evaluate each argument in sequence, and if any are ‘nil’, return
      ‘nil’; if none are ‘nil’, return the value of the last argument.
      In brief, return a true value only if all the arguments are true;
      return a true value if one _and_ each of the others is true.
 
 ‘&optional’
      A keyword used to indicate that an argument to a function
      definition is optional; this means that the function can be
      evaluated without the argument, if desired.
 
 ‘prefix-numeric-value’
      Convert the raw prefix argument produced by ‘(interactive "P")’ to
      a numeric value.
 
 ‘forward-line’
      Move point forward to the beginning of the next line, or if the
      argument is greater than one, forward that many lines.  If it can’t
      move as far forward as it is supposed to, ‘forward-line’ goes
      forward as far as it can and then returns a count of the number of
      additional lines it was supposed to move but couldn’t.
 
 ‘erase-buffer’
      Delete the entire contents of the current buffer.
 
 ‘bufferp’
      Return ‘t’ if its argument is a buffer; otherwise return ‘nil’.
 

Info Catalog eintr: beginning-of-buffer eintr: More Complex eintr: optional Exercise