Variables.cpp

#include "Variables.h"
#include <QDebug>

// manage storage of variables

// variables are limited to types (defined in Types.h):

int Variables::e = ERROR_NONE;


// T_REF is a variable number in the specified recursion level

// ************************************************************
// * the Variable object - defines a single value or an array *
// ************************************************************

Variable::Variable() {
	data = new DataElement();
}

Variable::~Variable() {
	delete(data);
}


// ************************************************************************
// * Variables contain the individual variable(s) for the recursion level *
// ************************************************************************

Variables::Variables(int n) :  numsyms(n){
	// n is the size of the symbol table
    recurselevel = -1;
    increaserecurse(); // go to recurse level 0 (main level)
	isglobal = new bool[numsyms];
	int i=numsyms;
	while(i-- > 0) {
		isglobal[i]=false;
	}
}

Variables::~Variables() {
	// free variables and all storage
	// delete a recurse level being sure to delete
	// the variables in the runlevel before removing itmake
	while(recurselevel >= 0) {
		decreaserecurse();
	}
	varmap.resize(0);
	delete[] isglobal;
}

QString Variables::debug() {
	// return a string representing the variables
	QString s("");
	if(!varmap.empty()) {
		for(int i=0;i<=recurselevel;i++) {
			s += QStringLiteral("recurse Level ") + QString::number(i) + "\n";
			for(int j=0; j < numsyms; j++) {
				s += QStringLiteral(" varnum ") + QString::number(j) + QStringLiteral(" ") ;
				s += varmap[i][j]->data->debug();
				s += "\n";
			}
			s += "\n";
		}
	}
	return s;
}

void Variables::increaserecurse() {
	// initialize a new recurse level
	// create a new Variable for each symbol at this recurse level
	// wasteful for the labels and jump points but vector is so fast
	// to access an element it does not matter	recurselevel++;
	if (recurselevel>=MAX_RECURSE_LEVELS) {
		recurselevel--;
		e = ERROR_MAXRECURSE;
	} else {
		recurselevel++;
		varmap.resize(recurselevel+1);
		varmap[recurselevel] = new Variable*[numsyms];
		int i=numsyms;
		while(i-- > 0) {
			varmap[recurselevel][i] = NULL;
		}

	}
}

int Variables::getrecurse() {
	return recurselevel;
}

void Variables::decreaserecurse() {
	if (recurselevel>=0) {
		int i=numsyms;
		while(i-- > 0) {
			if (varmap[recurselevel][i]) delete varmap[recurselevel][i];
		}
		delete varmap[recurselevel];
		// return back to prev variable context
		recurselevel--;
		varmap.resize(recurselevel+1);
	}
}


Variable* Variables::get(int varnum, int level) {
	// get v from map or follow REF to recurse level if needed
	Variable *v;
	//printf("variables::get - varnum %d level %d\n", varnum, level);
	v = getAt(varnum, level);
	if(DataElement::getType(v->data)==T_REF) {
		// reference to other level - recurse down the rabitty hole
		return get(v->data->intval, v->data->level);
	} else {
		return(v);
	}
}

Variable* Variables::get(int varnum) {
    return get(varnum, recurselevel);
}

Variable* Variables::getAt(int varnum, int level) {
	// get variable from map without follow REF
	// need for variable window too
	Variable *v;
	if(isglobal[varnum]) level = 0;
	v = varmap[level][varnum];
	if (not v) {
		v = new Variable();
		varmap[level][varnum] = v;
	}
	return v;
}

Variable* Variables::getAt(int varnum) {
	// get variable without recurse from this level
	return getAt(varnum, recurselevel);
}

DataElement* Variables::getData(int varnum) {
	// get data from variable - return varnum's data
	// DO NOT DELETE ****** COPY OF THE VARIABLE's INTERNAL STORAGE
	Variable *v = get(varnum);
	return v->data;
}


void Variables::setData(int varnum, DataElement* d) {
    // recieves a DataElement pointed pulled from the stack
    // e is a pointer in the stack vector AND MUST NOT BE DELETED
	Variable *v;
	if (DataElement::getType(d)==T_REF) {
		// if we are assigning a "REF" dont recurse down the previous ref is there is one
		// just assign it at the current run level.
		v = getAt(varnum);
	} else {
		v = get(varnum, recurselevel);
	}
	v->data->copy(d);
}

void Variables::setData(int varnum, long l) {
	Variable *v = get(varnum);
	v->data->clear();
	v->data->type = T_INT;
	v->data->intval = l;
}

void Variables::setData(int varnum, double f) {
	Variable *v = get(varnum);
	v->data->clear();
	v->data->type = T_FLOAT;
	v->data->floatval = f;
}

void Variables::setData(int varnum, QString s) {
	//fprintf(stderr,"s");
	Variable *v = get(varnum);
	v->data->clear();
	v->data->type = T_STRING;
	v->data->stringval = s;
}

void Variables::setData(int varnum, std::string s) {
	// used in foreach for maps
	setData(varnum, QString::fromStdString(s));
}

void Variables::unassign(int varnum) {
	//unassign true variable, not the reference (unlink)
	Variable *v = varmap[(recurselevel==0||isglobal[varnum])?0:recurselevel][varnum];
	v->data->clear();
}

void Variables::makeglobal(int varnum) {
	// make a variable global - if there is a value in a run level greater than 0 then
	// that value will be lost to the program
	isglobal[varnum] = true;
}