/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include <stdio.h>#include <stdlib.h>#include "grap.h"#include "y.tab.h" typedef struct {	Obj	*var;	/* index variable */	double	to;	/* limit */	double	by;	int	op;	/* operator */	char	*str;	/* string to push back */} For; #define	MAXFOR	10 For	forstk[MAXFOR];	/* stack of for loops */For	*forp = forstk;	/* pointer to current top */ void forloop(Obj *var, double from, double to, int op, double by, char *str)	/* set up a for loop */{	fprintf(tfd, "# for %s from %g to %g by %c %g \n",		var->name, from, to, op, by);	if (++forp >= forstk+MAXFOR)		ERROR "for loop nested too deep" FATAL;	forp->var = var;	forp->to = to;	forp->op = op;	forp->by = by;	forp->str = str;	setvar(var, from);	nextfor();	unput('\n');} void nextfor(void)	/* do one iteration of a for loop */{	/* BUG:  this should depend on op and direction */	if (forp->var->fval > SLOP * forp->to) {	/* loop is done */		free(forp->str);		if (--forp < forstk)			ERROR "forstk popped too far" FATAL;	} else {		/* another iteration */		pushsrc(String, "\nEndfor\n");		pushsrc(String, forp->str);	}} void endfor(void)	/* end one iteration of for loop */{	switch (forp->op) {	case '+':	case ' ':		forp->var->fval += forp->by;		break;	case '-':		forp->var->fval -= forp->by;		break;	case '*':		forp->var->fval *= forp->by;		break;	case '/':		forp->var->fval /= forp->by;		break;	}	nextfor();} char *ifstat(double expr, char *thenpart, char *elsepart){	dprintf("if %g then <%s> else <%s>\n", expr, thenpart, elsepart? elsepart : "");	if (expr) {		unput('\n');		pushsrc(Free, thenpart);		pushsrc(String, thenpart);		unput('\n');  		if (elsepart)			free(elsepart);		return thenpart;	/* to be freed later */	} else {		free(thenpart);		if (elsepart) {			unput('\n');			pushsrc(Free, elsepart);			pushsrc(String, elsepart);			unput('\n');		}		return elsepart;	}}