.. highlightlang:: us

.. index:: exptok

.. _exptok:

exptok
======

.. us.tag  exptok NOTREADYENGLISH ProgMisc Changed5511

:ref:`exptok` splits a simple arithmetic expression into tokens.

.. function::  ssToks = exptok(ssExpression)

.. us.return

**Return Value**

*ssToks* is a string of tokens. In case of an error *ssToks* is a number
containing the position of the error in *ssExpression*.The tokens are separated
by the character ``\2``. A token consists of a type and the token string. The
type and the token string are separated by the character ``\1``.

The following token types exist:

.. list-table::
   :header-rows: 1

   * - Type Value
     - Meaning
   * - F$n
     - Value is a function call. n is the number of parameters.
   * - V
     - Variable name.
   * - O
     - Operator ``+ - \ * / ^``.
   * - S
     - String
   * - N
     - Number
   * - C
     - Parenthesis ``(`` or ``)`` or Comma ``,``.

.. us.params

**Parameters**

.. uparam:: ssExpression

   *ssExpression* is an arithmetic expression. The following elements are allowed
   in the expression: Operators: ``+,-,*,/,^`` Parenthesis: ``(`` und ``)``
   Function names, variable names, string contants enclosed in ``"``-characters,
   also Strings and numbers of the form 1, 1.2, 1.2e3, -1.2e-3 Functions can have
   an empty parameter list as in ``print()`` or a list of parameters separated by
   a comma (``,``).

.. us.example

**Example**

.. highlight:: none

::

   toks = exptok("3 * sin(2.3) + abc / 1");
   * toks
   N3O*F$1sinC(N2.3C)O+VabcO/N1
   * toks = strtok(toks, "\1\2");
   * toks'
   N
   3
   O
   *
   F$1
   sin
   C
   (
   N
   2.3
   C
   )
   O
   +
   V
   abc
   O
   /
   N
   1

.. highlight:: us

.. seealso::
   :ref:`overview-programming`

:sub:`id-285600`