86 lines
1.4 KiB
C
86 lines
1.4 KiB
C
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/*
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* (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
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*
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* This product is part of the Amsterdam Compiler Kit.
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*
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* Permission to use, sell, duplicate or disclose this software must be
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* obtained in writing. Requests for such permissions may be sent to
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*
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* Dr. Andrew S. Tanenbaum
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* Wiskundig Seminarium
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* Vrije Universiteit
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* Postbox 7161
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* 1007 MC Amsterdam
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* The Netherlands
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*
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*/
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/* Author: E.G. Keizer */
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/* Test a few declaration features */
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/* Such as:
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forward function declarations,
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redeclarations,
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pointer to function declarations.
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*/
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static int sqr() ; /* forward declarations */
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extern int sqrt();
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main() {
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fdcl() ;
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hidden() ;
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return 0 ;
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}
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fdcl() {
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int (*a[2])() ;
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printf("sqr(4) %d\n",sqr(4)) ;
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a[0]=sqr ; a[1]=sqrt ;
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printf("(*a[0])(16) %d\n",(*a[0])(16) ) ;
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printf("(*a[1])( (*a[0])(3) ) %d\n", (*a[1])( (*a[0])(3) ) ) ;
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}
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static int sqr(par) int par ; {
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return par*par ;
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}
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int sqrt(par) int par ; {
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float x1,x2 ;
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int i ;
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if ( par<0 ) return -1 ;
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x1 = par ;
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i=0 ;
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do {
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x2 = x1 ;
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x1 = ( x2*x2 + par ) / (2*x2) ;
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if ( i++>=100 ) return -2 ;
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} while ( ( x2<x1 ? x1-x2 : x2-x1 ) > 1e-5 ) ;
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return (x1+x2)/2 ;
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}
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int a = -8 ;
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hidden() {
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hide() ;
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printf("a outside hide %d\n",a) ;
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}
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int hide() {
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int a ;
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a = 4 ;
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printf("a in hide %d\n",a) ;
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{
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int a ;
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a = 16 ;
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printf("a in in hide %d\n",a) ;
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}
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printf("a in hide %d\n",a) ;
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}
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