Re: translators and scoping rules (was: Re: language translator help)

[John W. Eaton]

On 28-Apr-2002, Per Bothner <address@hidden> wrote:

| Am I right in guesing that Octave uses dynamic scoping, rather than
| lexical scoping?

Are those the only choices?  :-)

The rules are essentially the same as for Fortran.  Variables are
local to functions (subroutines).  The only "global" variables are
declared global (common).  There is no statement like (let ...).
Functions are all in one global scope.  Functions (but not variables)
can be shadowed.  If a function is shadowed by a variable, "clearing"
the variable restores the function.  For example,

  octave:1> which sin
  sin is a builtin function
  octave:2> sin (pi/2)
  ans = 1
  octave:3> sin = 0
  sin = 0
  octave:4> which sin
  sin is a user-defined variable
  octave:5> clear sin
  octave:6> which sin
  sin is a builtin function
  octave:7> sin (pi/2)
  ans = 1

Well, my excuse is that I didn't make this up, I inherited it from
Matlab.

jwe