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    Eval Lite 0.7 (C)
    Author: Sadao Massago
            web: http://www2.dm.ufscar.br/~sadao
            e-mail: sadao@dm.ufscar.br

    Last change: June of 2003.

    CAUTION: For C++ version, see the MathEx on the SSCILIB site
	          http://sscilib.sourceforge.net/
	 The C version are not maintained except perphaps the bug fixes.
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    "Eval Lite 0.7" is probably the the last version of this C implementation of "Eval Lite",
	 but will contain bugs and the author DOES NOT ASSUME the responsability. 
	 The version change are due to bug that accept unary plus/minus operator after operator.
	 For C++ implementation, see the project page
	 I'm planning the implementation of these routine in C++ or Java.

    The program is freeware.
    The library/program that use "eval lite" will be distributed under license of your
    choice, since the notification of use are contained in thier doucument/help.
    The complete set of this files will be distributed freelly for non comercial purpose, 
    since respect the copyright.

    The development of "eval lite" is based on the fonte code of following two programa and 
	 the book of Niklaus Wirth (Algoritms and Data Structures):
    1. C Interpreter (little C): 
      Schildt, Helbert - "building your own C interpreter", Dr. Dobb's Jornal - August/1989.
      Schildt Helbert is the author of several book related to rogramming in C language.
      Address (USA): RR#1, Box 130, Mabomet, IL61853 
      home page of Dr. Dobb's journal: http://www.ddj.com
      The font code: Dr. Dobb's Journal, August/1989 or the CD-ROM of Dr. Dobb's Journal 
		(see http://www.ddj.com for detail).
    2. EE - Expression Evaluator (January 1992)
      Category: freeware.
      Author: Mark Morley
      Address (Canada):
         3889 Mildred Street
         Victoria, B.C.  Canada
         V8Z 7G1
         (604) 479-7861
     e-mail: morley@Camosun.BC.CA
     The font file of EE are downloadable from:
     http://www.simtel.net/pub/simtelnet/msdos/c/c-eval.zip
     or one of SIMMTEL NET's mirros such as http://ftp.unicamp.br

    The author are grates for above persons for the revelation of font code of their
	 implementations.
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    The main goal of this implemetation is the easy to use fast evaluator for mathematical 
	 expressions.
    The evaluation process are divided in two steps:
    - The procedure parse() compile the expression to pseudo byte code in Polonese 
	   (pos-fix mode) as sugested by Wirth.
    - The eval() evaluate the byte code and return the results.

    One of atractive of this implementation is the variable sharing features, 
	 i.e., the variables (used in the expression) are associated with internal C variable
	 by the function RegisterSharedVar() and the reference are obtained in the parsing time.

    Theses implementations gives more speed, but the size of code becames large than purelly 
	 interpreted one (compare with the little C and EE).
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    Obs.1: This acompanishes the translation of this document to portuguese one, for 
	        purpose of distribution in Brazil.
    Obs.2: These package does not contain tutorials. See the examples to understand the use.
    Obs.3: The functions SetValue()/GetValue() (used in EE) are implemented for 
	        demonstration purpose only. Since the variable are shared by internal one, 
			  will acess directly to obtain more speeed.
    Obs.4: Theses files are tested under DOS (Turbo C) and UNIX (gcc).
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 I am sorry for my English...
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  Sadao Massago
  DM/UFSCar - Sao Carlos - SP - Brazil
  http://www.dm.ufscar.br
  e-mail: sadao@dm.ufscar.br
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