[calc.git] / parser.c

#include <malloc.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

#include "debug.h"

#include "parser.h"

/* global variables */

double answer = 0;

#define STORAGE_SIZE 10
double storage[STORAGE_SIZE] = {0};

/* compare codes */

int codecmp (char *ref, char *str)
{
    int sig;

    while (*ref != '\0') {
        if (*ref == '\t') {
             sig = (*str == '.') ? -1 : ((*str >= '0') && (*str <= '9'));
        } else {
            sig = *str - *ref;
        }
        if (sig != 0) {
            return (sig > 0) ? 1 : -1;
        }
        str++;
        ref++;
    }

    return 0;
}

/* allocate new element */

element_t *newelement (func_t function, int nbops, int prio)
{
    element_t *new = (element_t *) calloc (1, sizeof (element_t));
    if (new == NULL) {
        VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
        return NULL;
    }
    new->func = function;
    new->nbops = nbops;
    new->prio = prio;

    return new;
}

/* desallocate element */

void delelement (element_t *root)
{
    int i;
    if ((root != NULL) && (root != ERROR_OP)) {
        for (i = 0; i < root->nbops; i++) {
            if ((root->ops[i] != NULL) && (root->ops[i] != ERROR_OP)) {
                delelement (root->ops[i]);
            }
        }
        free (root);
    }
}

/* duplicate element */

element_t *dupelement (element_t *root)
{
    element_t *tmp = NULL;
    int i;

    if ((root == NULL) || (root == ERROR_OP)) {
        return root;
    }
    tmp = newelement (root->func, root->nbops, root->prio);
    if (tmp == NULL) {
        return ERROR_OP;
    }
    tmp->value = root->value;
    for (i = 0; i < root->nbops; i++) {
        tmp->ops[i] = dupelement (root->ops[i]);
        if (tmp->ops[i] == ERROR_OP) {
            delelement (tmp);
            return ERROR_OP;
        }
    }
    return tmp;
}

/* functions */

#define NB_OPERATORS 14
keyword_t operators[NB_OPERATORS] = {
    { "+\t", Add, 2, 1, 1},
    { "-\t", Sub, 2, 1, 1},
    { "*",   Mul, 2, 1, 2},
    { "/",   Div, 2, 1, 2},
    { "%",   Mod, 2, 1, 3},
    { "^",   Pow, 2, 1, 4},
    { "==",  Equal, 2, 2, -1},
    { "!=",  Diff, 2, 2, -1},
    { ">=",  Ge, 2, 2, -1},
    { "<=",  Le, 2, 2, -1},
    { ">",   Gt, 2, 1, -1},
    { "<",   Lt, 2, 1, -1},
    { "&",   And, 2, 1, -2},
    { "|",   Or, 2, 1, -2}
};

#define NB_FUNCTIONS 17
keyword_t functions[NB_FUNCTIONS] = {
    { "sqrt", Sqr, 1, 4, 5},
    { "pow",  Pow, 2, 3, 5},
    { "cos",  Cos, 1, 3, 5},
    { "sin",  Sin, 1, 3, 5},
    { "atan", Atan, 1, 4, 5},
    { "exp",  Exp, 1, 3, 5},
    { "log",  Log, 1, 3, 5},
    { "sto",  Store, 2, 3, 5},
    { "rcl",  Recall, 1, 3, 5},
    { "inc",  Inc, 1, 3, 5},
    { "dec",  Dec, 1, 3, 5},
    { "disp", Disp, 0, 4, 9},
    { "quit", Quit, 0, 4, 9},
    { "help", Help, 0, 4, 9},
    { "!",    Not, 1, 1, 6},
    { "cond", Cond, 3, 4, 5},
    { "whl",  While, 2, 3, 5}
};

#define NB_CONSTANTS 3
keyword_t constants[NB_CONSTANTS] = {
    { "ans", Ans, 0, 3, 5},
    { "e",   E, 0, 1, 5},
    { "pi",  Pi, 0, 2, 5}
};

/* subparser function */

element_t *subparser (element_t **proot, char **pstr, func_t func, int nbops, int prio)
{
    element_t *new = newelement (func, nbops, prio);
    if (new == NULL) {
        return ERROR_OP;
    }
    new->ops[0] = *proot;
    new->ops[1] = parser (*pstr, pstr, new->prio);
    if ((new->ops[1] == NULL) || ((new->ops[1] != ERROR_OP) && (new->ops[1]->prio == 9))) {
        delelement (new->ops[1]);
        new->ops[1] = ERROR_OP;
    }
    if (new->ops[1] == ERROR_OP) {
        delelement (new);
        *proot = NULL;
        return ERROR_OP;
    }
    *proot = newelement (Val, 1, 5);
    if (*proot == NULL) {
        delelement (new);
        return ERROR_OP;
    }
    (*proot)->ops[0] = new;

    return *proot;
}

/* parser function */

element_t *parser (char *str, char **next, int prio)
{
    element_t *root = NULL;
    int i;

    VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));

    /* main loop */
    while (*str != '\0') {
        int found = 0;
        element_t *new = NULL;
        VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));

        /* skip spaces and tabs */

        if ((*str == ' ') || (*str == '\t')) {
            str++;
            continue;
        }

        /* check for open bracket */

        if (*str == '(') {
            VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
            if (root) {
                do {
                    found = 0;
                    new = parser (str + 1, &str, 0);
                    if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
                        delelement (new);
                        new = ERROR_OP;
                    }
                    if ((new == NULL) || (new == ERROR_OP)) {
                        delelement (root);
                        return ERROR_OP;
                    }
                    for (i = 0; i < root->nbops; i++) {
                        if (root->ops[i] == NULL) {
                            root->ops[i] = new;
                            found = 1;
                            break;
                        }
                    }
                    if (!found) {
                        delelement (new);
                        delelement (root);
                        return ERROR_OP;
                    }
                } while (*str == ',');
            } else {
                root = newelement (Val, 1, 5);
                if (root == NULL) {
                    return ERROR_OP;
                }
                new = parser (str + 1, &str, 0);
                if ((new == NULL) || ((new != ERROR_OP) && (new->prio == 9))) {
                    delelement (new);
                    new = ERROR_OP;
                }
                if ((new == NULL) || (new == ERROR_OP) || (*str == ',')) {
                    delelement (new);
                    delelement (root);
                    return ERROR_OP;
                }
                root->ops[0] = new;
            }
            if (*str != ')') {
                delelement (root);
                return ERROR_OP;
            }
            str++;
            VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
            continue;
        }

        /* check for closing bracket or koma */

        if ((*str == ')') || (*str == ',')) {
            if (next != NULL) {
                *next = str;
            }
            return root;
        }

        /* look for operators */

        for (i = 0; i < NB_OPERATORS; i++) {
            keyword_t *operator = operators + i;
            if (codecmp (operator->keyword, str) == 0) {
                VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
                if (root) {
                    if ((prio) && (prio > operator->prio)) {
                        VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
                        *next = str;
                        return root;
                    }
                    str += operator->offset;
                    VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
                    if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
                        delelement (root);
                        return ERROR_OP;
                    }
                } else if (*str == '-') {
                    new = newelement (Sig, 1, 9);
                    if (new == NULL) {
                        return ERROR_OP;
                    }
                    root = new;
                } else {
                    return ERROR_OP;
                }
                found = 1;
                VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
                break;
            }
        }
        if (found) {
            continue;
        }

        /* look for functions */

        for (i = 0; i < NB_FUNCTIONS; i++) {
            keyword_t *function = functions + i;
            if (codecmp (function->keyword, str) == 0) {
                VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
                if (root == NULL) {
                    VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
                    new = newelement (function->func, function->nbops, function->prio);
                    if (new == NULL) {
                        return ERROR_OP;
                    }
                    root = new;
                } else {
                    delelement (root);
                    return ERROR_OP;
                }
                str += function->offset;
                found = 1;
                VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
                break;
            }
        }
        if (found) {
            continue;
        }

        /* look for constant */

        for (i = 0; i < NB_CONSTANTS; i++) {
            keyword_t *constant = constants + i;
            if (codecmp (constant->keyword, str) == 0) {
                VERBOSE (DEBUG, fprintf (stdout, "start processing constant\n"));
                if (root == NULL) {
                    VERBOSE (INFO, fprintf (stdout, "Const: %d\n", constant->func));
                    new = newelement (constant->func, constant->nbops, constant->prio);
                    if (new == NULL) {
                        return ERROR_OP;
                    }
                    root = new;
                } else {
                    delelement (root);
                    return ERROR_OP;
                }
                str += constant->offset;
                found = 1;
                VERBOSE (DEBUG, fprintf (stdout, "stop processing constant\n"));
                break;
            }
        }
        if (found) {
            continue;
        }

        /* look for number */

        if (((*str >= '0') && (*str <= '9')) ||
            (*str == '.') || (*str == '+') || (*str == '-')) {
            VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
            char *pt;
            double value = strtod (str, &pt);
            VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
            if (str != pt) {
                if ((root == NULL) || (root->prio == 6)) {
                    new = newelement (Val, 1, 5);
                    if (new == NULL) {
                        return ERROR_OP;
                    }
                    new->value = value;
                    if (root == NULL) {
                        root = new;
                    } else {
                        for (i = 0; i < root->nbops; i++) {
                            if (root->ops[i] == NULL) {
                                root->ops[i] = new;
                                found = 1;
                                break;
                            }
                        }
                        if (!found) {
                            delelement (new);
                            delelement (root);
                            return ERROR_OP;
                        }
                    }
                    str = pt;
                } else if ((*str == '+') || (*str == '-')) {
                    if ((prio) && (prio > 1)) {
                        VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
                        *next = str;
                        return root;
                    }
                    if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
                        delelement (root);
                        return ERROR_OP;
                    }
                } else {
                    delelement (root);
                    return ERROR_OP;
                }
                found = 1;
            }
            VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
        }

        /* error */

        if (!found) {
            delelement (root);
            return ERROR_OP;
        }

    }

    if (next != NULL) {
        *next = str;
    }

    return root;
}

/* print element tree */

void print_element (element_t *root, int level)
{
    char *func = NULL;
    int i;

    if ((root == NULL) || (root == ERROR_OP)) {
        return;
    }

    for (i = 0; i < level; i++) {
        fprintf (stdout, " ");
    }

    switch (root->func) {
    case Val: func = "Value"; break;
    case Sig: func = "Sign"; break;
    case Add: func = "Addition"; break;
    case Sub: func = "Subtraction"; break;
    case Mul: func = "Multiplication"; break;
    case Div: func = "Division"; break;
    case Mod: func = "Modulo"; break;
    case Pow: func = "Power"; break;
    case Sqr: func = "Square Root"; break;
    case Cos: func = "Cosine"; break;
    case Sin: func = "Sine"; break;
    case Atan: func = "Arc Tangent"; break;
    case Log: func = "Logarithm"; break;
    case Exp: func = "Exponantial"; break;
    case Store: func = "Store"; break;
    case Recall: func = "Recall"; break;
    case Inc: func = "Increase"; break;
    case Dec: func = "Decrease"; break;
    case Disp: func = "Display"; break;
    case Quit: func = "Quit"; break;
    case Help: func = "Help"; break;
    case Ans: func = "Ans"; break;
    case Pi: func = "Pi"; break;
    case E: func = "E"; break;
    case Equal: func = "Equal"; break;
    case Diff: func = "Different"; break;
    case Ge: func = "Greater or equal"; break;
    case Le: func = "Lesser or equal"; break;
    case Gt: func = "Greater"; break;
    case Lt: func = "Lesser"; break;
    case And: func = "And"; break;
    case Or: func = "Or"; break;
    case Not: func = "Not"; break;
    case Cond: func = "Condition"; break;
    case While: func = "While"; break;
    }

    fprintf (stdout, "Function: %s\n", func);

    if ((root->func == Val) && (root->ops[0] == NULL)) {
        for (i = 0; i < level; i++) {
            fprintf (stdout, " ");
        }
        fprintf (stdout, "value: %f\n", root->value);
    } else {
        for (i = 0; i < root->nbops; i++) {
            print_element (root->ops[i], level + 1);
        }
    }
}

/* storage functions */

double store (int index, double value)
{
    if ((index > 0) && (index <= STORAGE_SIZE)) {
        storage[index - 1] = value;
    } else {
        VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
    }
    return value;
}

double recall (int index)
{
    if ((index > 0) && (index <= STORAGE_SIZE)) {
        return storage[index - 1];
    } else {
        VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
    }
    return 0;
}

double increase (int index)
{
    if ((index > 0) && (index <= STORAGE_SIZE)) {
        return storage[index - 1]++;
    } else {
        VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
    }
    return 0;
}

double decrease (int index)
{
    if ((index > 0) && (index <= STORAGE_SIZE)) {
        return storage[index - 1]--;
    } else {
        VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
    }
    return 0;
}

void display (void)
{
    int i;
    fprintf (stdout, "storage:");
    for (i = 0; i < STORAGE_SIZE; i++) {
        fprintf (stdout, " %g", storage[i]);
    }
    fprintf (stdout, "\n");
}

/* While do function */

double while_do (element_t *cond, element_t *action)
{
    double ret = 0;
    element_t *temp = NULL;

    VERBOSE (DEBUG, fprintf (stdout, "starting while loop\n"));
    if (cond == NULL) {
        return ret;
    }
    while (1) {
        VERBOSE (DEBUG, fprintf (stdout, "loop...\n"));

        temp = dupelement (cond);
        if (!evaluate_element (temp, 0)) {
            break;
        }
        if (action) {
            temp = dupelement (action);
            ret = evaluate_element (temp, 0);
        }
    }

    VERBOSE (DEBUG, fprintf (stdout, "ending while loop\n"));

    return ret;
}

/* quit function */

void quit (void)
{
    fprintf (stdout, "bye\n");
    exit (0);
}

/* help message */

void help (void)
{
    fprintf (stdout, "calc is a simple calculator\n\n");
    fprintf (stdout, "supported operators:");
    fprintf (stdout, " + - * / %% ^\n");
    fprintf (stdout, "camparison operators:");
    fprintf (stdout, " == != >= <= > <\n");
    fprintf (stdout, "logical operators:");
    fprintf (stdout, " & | !\n");
    fprintf (stdout, "supported functions:");
    fprintf (stdout, " pow sqrt cos sin atan log exp\n");
    fprintf (stdout, "storage functions:");
    fprintf (stdout, " sto rcl inc dec\n");
    fprintf (stdout, "conditional functions:");
    fprintf (stdout, " cond\n");
    fprintf (stdout, "miscellaneous functions:");
    fprintf (stdout, " quit help\n");
    fprintf (stdout, "supported constants:");
    fprintf (stdout, " e pi\n");
}

/* evaluate element tree */

#define MASK_SUB 0x1
#define MASK_DIV 0x2

double evaluate_element (element_t *root, char mask)
{
    double op0 = 0, op1 = 0;
    char nextmask = mask;

    if ((root == NULL) || (root == ERROR_OP)) {
        VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
        return 0;
    }

    /* mask to manage sub operator sub and div */
    switch (root->func) {
    case Add:
        nextmask &= ~MASK_SUB;
        nextmask &= ~MASK_DIV;
        break;
    case Sub:
        nextmask |= MASK_SUB;
        nextmask &= ~MASK_DIV;
        break;
    case Mul:
        nextmask &= ~MASK_DIV;
        break;
    case Div:
        nextmask |= MASK_DIV;
        break;
    default:
        nextmask = mask;
    }

    switch (root->func) {
    case Val:
    case Sig:
        op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
        break;
    case Add:
    case Sub:
    case Mul:
    case Div:
    case Mod:
    case Pow:
    case Store:
    case Equal:
    case Diff:
    case Ge:
    case Le:
    case Gt:
    case Lt:
    case And:
    case Or:
        if (root->ops[1]) {
            op1 = evaluate_element (root->ops[1], nextmask);
        } else if (root->func != Store) {
            VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
            return 0;
        }
        /* fallthrough */
    case Sqr:
    case Cos:
    case Sin:
    case Atan:
    case Log:
    case Exp:
    case Recall:
    case Inc:
    case Dec:
    case Not:
    case Cond:
        if (root->ops[0]) {
            op0 = evaluate_element (root->ops[0], 0);
        } else {
            VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
            return 0;
        }
        break;
    case Disp:
    case Quit:
    case Help:
    case Ans:
    case Pi:
    case E:
        break;
    case While:
        if (root->ops[0] == NULL) {
            VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
            return 0;
        }
        break;
    }

    switch (root->func) {
    case Val: return op0;
    case Sig: return -op0;
    case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
    case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
    case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
    case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
    case Mod: return fmod (op0, op1);
    case Pow: return pow (op0, op1);
    case Sqr: return sqrt (op0);
    case Cos: return cos (op0);
    case Sin: return sin (op0);
    case Atan: return atan (op0);
    case Log: return log (op0);
    case Exp: return exp (op0);
    case Store: return store ((int)op0, (op1) ? op1 : answer);
    case Recall: return recall ((int)op0);
    case Inc: return increase ((int)op0);
    case Dec: return decrease ((int)op0);
    case Disp: display (); break;
    case Quit: quit (); break;
    case Help: help (); break;
    case Ans: return answer;
    case Pi: return M_PI;
    case E: return M_E;
    case Equal: return op0 == op1;
    case Diff: return op0 != op1;
    case Ge: return op0 >= op1;
    case Le: return op0 <= op1;
    case Gt: return op0 > op1;
    case Lt: return op0 < op1;
    case And: return (op0 != 0) && (op1 != 0);
    case Or: return (op0 != 0) || (op1 != 0);
    case Not: return (op0 == 0);
    case Cond:
        if ((op0) && (root->ops[1])) {
            return evaluate_element (root->ops[1], 0);
        } else if ((!op0) && (root->ops[2])) {
            return evaluate_element (root->ops[2], 0);
        } else {
            return 0;
        }
    case While: return while_do (root->ops[0], root->ops[1]);
    }

    return 0;
}

/* vim: set ts=4 sw=4 et: */
Commit	Line	Data
bc97a989	1	#include <malloc.h>
f2927108	2	#include <math.h>
87621fe1	3	#include <stdio.h>
bc97a989 LM	4	#include <stdlib.h>
	5
	6	#include "debug.h"
bc97a989 LM	7
	8	#include "parser.h"
	9
5075f6ea LM	10	/* global variables */
	11
	12	double answer = 0;
	13
6ba1dd0f LM	14	#define STORAGE_SIZE 10
	15	double storage[STORAGE_SIZE] = {0};
	16
bc97a989 LM	17	/* compare codes */
	18
	19	int codecmp (char ref, char str)
	20	{
	21	int sig;
	22
	23	while (*ref != '\0') {
0b9cc9b0 LM	24	if (*ref == '\t') {
	25	sig = (str == '.') ? -1 : ((str >= '0') && (*str <= '9'));
	26	} else {
	27	sig = str - ref;
	28	}
bc97a989 LM	29	if (sig != 0) {
	30	return (sig > 0) ? 1 : -1;
	31	}
0b9cc9b0 LM	32	str++;
0b9cc9b0 LM	33	ref++;
bc97a989 LM	34	}
	35
	36	return 0;
	37	}
	38
	39	/* allocate new element */
	40
11cda8d7	41	element_t *newelement (func_t function, int nbops, int prio)
bc97a989 LM	42	{
	43	element_t new = (element_t ) calloc (1, sizeof (element_t));
	44	if (new == NULL) {
04d68907	45	VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
bc97a989 LM	46	return NULL;
	47	}
	48	new->func = function;
	49	new->nbops = nbops;
11cda8d7	50	new->prio = prio;
bc97a989 LM	51
	52	return new;
	53	}
	54
031d7bba LM	55	/* desallocate element */
	56
	57	void delelement (element_t *root)
	58	{
	59	int i;
	60	if ((root != NULL) && (root != ERROR_OP)) {
	61	for (i = 0; i < root->nbops; i++) {
	62	if ((root->ops[i] != NULL) && (root->ops[i] != ERROR_OP)) {
	63	delelement (root->ops[i]);
	64	}
	65	}
	66	free (root);
	67	}
	68	}
	69
2a688642 LM	70	/* duplicate element */
	71
	72	element_t dupelement (element_t root)
	73	{
	74	element_t *tmp = NULL;
	75	int i;
	76
	77	if ((root == NULL) \|\| (root == ERROR_OP)) {
	78	return root;
	79	}
	80	tmp = newelement (root->func, root->nbops, root->prio);
	81	if (tmp == NULL) {
	82	return ERROR_OP;
	83	}
	84	tmp->value = root->value;
	85	for (i = 0; i < root->nbops; i++) {
	86	tmp->ops[i] = dupelement (root->ops[i]);
	87	if (tmp->ops[i] == ERROR_OP) {
	88	delelement (tmp);
	89	return ERROR_OP;
	90	}
	91	}
	92	return tmp;
	93	}
	94
bc97a989 LM	95	/* functions */
bc97a989 LM	96
ca3e2a2f	97	#define NB_OPERATORS 14
bc97a989	98	keyword_t operators[NB_OPERATORS] = {
11cda8d7 LM	99	{ "+\t", Add, 2, 1, 1},
	100	{ "-\t", Sub, 2, 1, 1},
	101	{ "*", Mul, 2, 1, 2},
	102	{ "/", Div, 2, 1, 2},
c47a9298	103	{ "%", Mod, 2, 1, 3},
7fe742c9	104	{ "^", Pow, 2, 1, 4},
ca3e2a2f LM	105	{ "==", Equal, 2, 2, -1},
	106	{ "!=", Diff, 2, 2, -1},
	107	{ ">=", Ge, 2, 2, -1},
	108	{ "<=", Le, 2, 2, -1},
	109	{ ">", Gt, 2, 1, -1},
	110	{ "<", Lt, 2, 1, -1},
	111	{ "&", And, 2, 1, -2},
	112	{ "\|", Or, 2, 1, -2}
bc97a989 LM	113	};
bc97a989 LM	114
2a688642	115	#define NB_FUNCTIONS 17
bc97a989	116	keyword_t functions[NB_FUNCTIONS] = {
c47a9298 LM	117	{ "sqrt", Sqr, 1, 4, 5},
	118	{ "pow", Pow, 2, 3, 5},
	119	{ "cos", Cos, 1, 3, 5},
	120	{ "sin", Sin, 1, 3, 5},
471da7c9	121	{ "atan", Atan, 1, 4, 5},
c47a9298	122	{ "exp", Exp, 1, 3, 5},
89cf0955	123	{ "log", Log, 1, 3, 5},
2a688642	124	{ "sto", Store, 2, 3, 5},
6ba1dd0f	125	{ "rcl", Recall, 1, 3, 5},
a8cf32ba LM	126	{ "inc", Inc, 1, 3, 5},
a8cf32ba LM	127	{ "dec", Dec, 1, 3, 5},
ca3e2a2f LM	128	{ "disp", Disp, 0, 4, 9},
	129	{ "quit", Quit, 0, 4, 9},
	130	{ "help", Help, 0, 4, 9},
94b4e517	131	{ "!", Not, 1, 1, 6},
2a688642 LM	132	{ "cond", Cond, 3, 4, 5},
2a688642 LM	133	{ "whl", While, 2, 3, 5}
471da7c9 LM	134	};
471da7c9 LM	135
5075f6ea	136	#define NB_CONSTANTS 3
471da7c9	137	keyword_t constants[NB_CONSTANTS] = {
5075f6ea LM	138	{ "ans", Ans, 0, 3, 5},
	139	{ "e", E, 0, 1, 5},
	140	{ "pi", Pi, 0, 2, 5}
bc97a989 LM	141	};
bc97a989 LM	142
d2ff8478 LM	143	/* subparser function */
	144
	145	element_t subparser (element_t proot, char *pstr, func_t func, int nbops, int prio)
	146	{
	147	element_t *new = newelement (func, nbops, prio);
	148	if (new == NULL) {
	149	return ERROR_OP;
	150	}
	151	new->ops[0] = *proot;
	152	new->ops[1] = parser (*pstr, pstr, new->prio);
686c4bc2	153	if ((new->ops[1] == NULL) \|\| ((new->ops[1] != ERROR_OP) && (new->ops[1]->prio == 9))) {
67b13e3d LM	154	delelement (new->ops[1]);
	155	new->ops[1] = ERROR_OP;
	156	}
d2ff8478	157	if (new->ops[1] == ERROR_OP) {
031d7bba LM	158	delelement (new);
031d7bba LM	159	*proot = NULL;
d2ff8478 LM	160	return ERROR_OP;
d2ff8478 LM	161	}
3b4b0bbe	162	*proot = newelement (Val, 1, 5);
031d7bba LM	163	if (*proot == NULL) {
031d7bba LM	164	delelement (new);
d2ff8478 LM	165	return ERROR_OP;
	166	}
	167	(*proot)->ops[0] = new;
	168
	169	return *proot;
	170	}
	171
bc97a989 LM	172	/* parser function */
bc97a989 LM	173
ef37d966	174	element_t parser (char str, char **next, int prio)
0b489a77	175	{
bc97a989	176	element_t *root = NULL;
85b4a72c	177	int i;
bc97a989	178
04d68907	179	VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));
49223129	180
bc97a989 LM	181	/* main loop */
	182	while (*str != '\0') {
	183	int found = 0;
	184	element_t *new = NULL;
04d68907	185	VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));
bc97a989 LM	186
	187	/* skip spaces and tabs */
	188
	189	if ((str == ' ') \|\| (str == '\t')) {
	190	str++;
	191	continue;
	192	}
	193
85b4a72c	194	/* check for open bracket */
0b489a77	195
0b489a77	196	if (*str == '(') {
04d68907	197	VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
0b489a77	198	if (root) {
85b4a72c LM	199	do {
85b4a72c LM	200	found = 0;
ef37d966	201	new = parser (str + 1, &str, 0);
686c4bc2	202	if ((new == NULL) \|\| ((new != ERROR_OP) && (new->prio == 9))) {
67b13e3d LM	203	delelement (new);
	204	new = ERROR_OP;
	205	}
686c4bc2	206	if ((new == NULL) \|\| (new == ERROR_OP)) {
031d7bba	207	delelement (root);
85b4a72c LM	208	return ERROR_OP;
	209	}
	210	for (i = 0; i < root->nbops; i++) {
	211	if (root->ops[i] == NULL) {
0b489a77 LM	212	root->ops[i] = new;
	213	found = 1;
	214	break;
	215	}
	216	}
85b4a72c	217	if (!found) {
031d7bba LM	218	delelement (new);
031d7bba LM	219	delelement (root);
85b4a72c LM	220	return ERROR_OP;
	221	}
	222	} while (*str == ',');
	223	} else {
3b4b0bbe	224	root = newelement (Val, 1, 5);
85b4a72c	225	if (root == NULL) {
0b489a77 LM	226	return ERROR_OP;
0b489a77 LM	227	}
ef37d966	228	new = parser (str + 1, &str, 0);
686c4bc2	229	if ((new == NULL) \|\| ((new != ERROR_OP) && (new->prio == 9))) {
67b13e3d LM	230	delelement (new);
	231	new = ERROR_OP;
	232	}
686c4bc2	233	if ((new == NULL) \|\| (new == ERROR_OP) \|\| (*str == ',')) {
031d7bba LM	234	delelement (new);
031d7bba LM	235	delelement (root);
efdfb543 LM	236	return ERROR_OP;
efdfb543 LM	237	}
85b4a72c	238	root->ops[0] = new;
0b489a77	239	}
3c0db5bc LM	240	if (*str != ')') {
	241	delelement (root);
	242	return ERROR_OP;
	243	}
85b4a72c	244	str++;
04d68907	245	VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
efdfb543	246	continue;
49223129	247	}
85b4a72c LM	248
	249	/* check for closing bracket or koma */
	250
	251	if ((str == ')') \|\| (str == ',')) {
49223129	252	if (next != NULL) {
85b4a72c	253	*next = str;
49223129 LM	254	}
49223129 LM	255	return root;
0b489a77 LM	256	}
0b489a77 LM	257
bc97a989 LM	258	/* look for operators */
	259
	260	for (i = 0; i < NB_OPERATORS; i++) {
	261	keyword_t *operator = operators + i;
	262	if (codecmp (operator->keyword, str) == 0) {
04d68907	263	VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
11cda8d7	264	if (root) {
ef37d966	265	if ((prio) && (prio > operator->prio)) {
04d68907	266	VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
ef37d966 LM	267	*next = str;
	268	return root;
	269	}
	270	str += operator->offset;
04d68907	271	VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
d2ff8478	272	if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
031d7bba	273	delelement (root);
ef37d966	274	return ERROR_OP;
11cda8d7	275	}
3b4b0bbe LM	276	} else if (*str == '-') {
	277	new = newelement (Sig, 1, 9);
	278	if (new == NULL) {
	279	return ERROR_OP;
	280	}
	281	root = new;
49223129	282	} else {
0b489a77	283	return ERROR_OP;
bc97a989	284	}
bc97a989	285	found = 1;
04d68907	286	VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
bc97a989 LM	287	break;
	288	}
	289	}
	290	if (found) {
bc97a989 LM	291	continue;
bc97a989 LM	292	}
49223129	293
bc97a989 LM	294	/* look for functions */
	295
	296	for (i = 0; i < NB_FUNCTIONS; i++) {
	297	keyword_t *function = functions + i;
	298	if (codecmp (function->keyword, str) == 0) {
04d68907	299	VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
bc97a989	300	if (root == NULL) {
04d68907	301	VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
11cda8d7	302	new = newelement (function->func, function->nbops, function->prio);
bc97a989	303	if (new == NULL) {
0b489a77	304	return ERROR_OP;
bc97a989 LM	305	}
bc97a989 LM	306	root = new;
031d7bba LM	307	} else {
031d7bba LM	308	delelement (root);
0b489a77	309	return ERROR_OP;
bc97a989 LM	310	}
	311	str += function->offset;
	312	found = 1;
04d68907	313	VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
bc97a989 LM	314	break;
	315	}
	316	}
	317	if (found) {
bc97a989 LM	318	continue;
	319	}
	320
471da7c9 LM	321	/* look for constant */
	322
	323	for (i = 0; i < NB_CONSTANTS; i++) {
	324	keyword_t *constant = constants + i;
	325	if (codecmp (constant->keyword, str) == 0) {
	326	VERBOSE (DEBUG, fprintf (stdout, "start processing constant\n"));
	327	if (root == NULL) {
5075f6ea	328	VERBOSE (INFO, fprintf (stdout, "Const: %d\n", constant->func));
471da7c9 LM	329	new = newelement (constant->func, constant->nbops, constant->prio);
	330	if (new == NULL) {
	331	return ERROR_OP;
	332	}
	333	root = new;
	334	} else {
	335	delelement (root);
	336	return ERROR_OP;
	337	}
	338	str += constant->offset;
	339	found = 1;
	340	VERBOSE (DEBUG, fprintf (stdout, "stop processing constant\n"));
	341	break;
	342	}
	343	}
	344	if (found) {
	345	continue;
	346	}
	347
bc97a989 LM	348	/* look for number */
bc97a989 LM	349
0b9cc9b0 LM	350	if (((str >= '0') && (str <= '9')) \|\|
0b9cc9b0 LM	351	(str == '.') \|\| (str == '+') \|\| (*str == '-')) {
04d68907	352	VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
bc97a989	353	char *pt;
fd88e359	354	double value = strtod (str, &pt);
04d68907	355	VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
bc97a989	356	if (str != pt) {
ce6627f2	357	if ((root == NULL) \|\| (root->prio == 6)) {
3b4b0bbe	358	new = newelement (Val, 1, 5);
c47a9298 LM	359	if (new == NULL) {
	360	return ERROR_OP;
	361	}
	362	new->value = value;
ce6627f2 LM	363	if (root == NULL) {
	364	root = new;
	365	} else {
	366	for (i = 0; i < root->nbops; i++) {
	367	if (root->ops[i] == NULL) {
	368	root->ops[i] = new;
	369	found = 1;
	370	break;
	371	}
	372	}
	373	if (!found) {
	374	delelement (new);
	375	delelement (root);
	376	return ERROR_OP;
	377	}
	378	}
c47a9298	379	str = pt;
32741902 LM	380	} else if ((str == '+') \|\| (str == '-')) {
	381	if ((prio) && (prio > 1)) {
	382	VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
	383	*next = str;
	384	return root;
	385	}
	386	if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
031d7bba	387	delelement (root);
0b489a77	388	return ERROR_OP;
bc97a989	389	}
0b9cc9b0	390	} else {
031d7bba	391	delelement (root);
0b9cc9b0	392	return ERROR_OP;
bc97a989	393	}
bc97a989 LM	394	found = 1;
bc97a989 LM	395	}
04d68907	396	VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
bc97a989 LM	397	}
	398
	399	/* error */
	400
	401	if (!found) {
031d7bba	402	delelement (root);
0b489a77	403	return ERROR_OP;
bc97a989 LM	404	}
	405
	406	}
	407
49223129 LM	408	if (next != NULL) {
	409	*next = str;
	410	}
031d7bba	411
bc97a989 LM	412	return root;
	413	}
	414
	415	/* print element tree */
	416
	417	void print_element (element_t *root, int level)
	418	{
	419	char *func = NULL;
	420	int i;
	421
49223129	422	if ((root == NULL) \|\| (root == ERROR_OP)) {
bc97a989	423	return;
49223129 LM	424	}
49223129 LM	425
bc97a989	426	for (i = 0; i < level; i++) {
04d68907	427	fprintf (stdout, " ");
bc97a989 LM	428	}
	429
	430	switch (root->func) {
	431	case Val: func = "Value"; break;
89cf0955	432	case Sig: func = "Sign"; break;
bc97a989 LM	433	case Add: func = "Addition"; break;
	434	case Sub: func = "Subtraction"; break;
	435	case Mul: func = "Multiplication"; break;
	436	case Div: func = "Division"; break;
c47a9298	437	case Mod: func = "Modulo"; break;
bc97a989 LM	438	case Pow: func = "Power"; break;
	439	case Sqr: func = "Square Root"; break;
	440	case Cos: func = "Cosine"; break;
	441	case Sin: func = "Sine"; break;
471da7c9	442	case Atan: func = "Arc Tangent"; break;
bc97a989 LM	443	case Log: func = "Logarithm"; break;
bc97a989 LM	444	case Exp: func = "Exponantial"; break;
6ba1dd0f LM	445	case Store: func = "Store"; break;
6ba1dd0f LM	446	case Recall: func = "Recall"; break;
a8cf32ba LM	447	case Inc: func = "Increase"; break;
a8cf32ba LM	448	case Dec: func = "Decrease"; break;
6ba1dd0f	449	case Disp: func = "Display"; break;
471da7c9 LM	450	case Quit: func = "Quit"; break;
471da7c9 LM	451	case Help: func = "Help"; break;
5075f6ea	452	case Ans: func = "Ans"; break;
471da7c9 LM	453	case Pi: func = "Pi"; break;
471da7c9 LM	454	case E: func = "E"; break;
7fe742c9 LM	455	case Equal: func = "Equal"; break;
	456	case Diff: func = "Different"; break;
	457	case Ge: func = "Greater or equal"; break;
	458	case Le: func = "Lesser or equal"; break;
	459	case Gt: func = "Greater"; break;
	460	case Lt: func = "Lesser"; break;
ca3e2a2f LM	461	case And: func = "And"; break;
	462	case Or: func = "Or"; break;
	463	case Not: func = "Not"; break;
94b4e517	464	case Cond: func = "Condition"; break;
2a688642	465	case While: func = "While"; break;
bc97a989 LM	466	}
bc97a989 LM	467
04d68907	468	fprintf (stdout, "Function: %s\n", func);
bc97a989	469
85b4a72c	470	if ((root->func == Val) && (root->ops[0] == NULL)) {
bc97a989	471	for (i = 0; i < level; i++) {
04d68907	472	fprintf (stdout, " ");
bc97a989	473	}
04d68907	474	fprintf (stdout, "value: %f\n", root->value);
bc97a989 LM	475	} else {
	476	for (i = 0; i < root->nbops; i++) {
	477	print_element (root->ops[i], level + 1);
	478	}
	479	}
	480	}
	481
6ba1dd0f LM	482	/* storage functions */
6ba1dd0f LM	483
3639df66	484	double store (int index, double value)
6ba1dd0f LM	485	{
6ba1dd0f LM	486	if ((index > 0) && (index <= STORAGE_SIZE)) {
3639df66	487	storage[index - 1] = value;
6ba1dd0f LM	488	} else {
	489	VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
	490	}
3639df66	491	return value;
6ba1dd0f LM	492	}
	493
	494	double recall (int index)
	495	{
	496	if ((index > 0) && (index <= STORAGE_SIZE)) {
	497	return storage[index - 1];
	498	} else {
	499	VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
	500	}
	501	return 0;
	502	}
	503
a8cf32ba LM	504	double increase (int index)
	505	{
	506	if ((index > 0) && (index <= STORAGE_SIZE)) {
	507	return storage[index - 1]++;
	508	} else {
	509	VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
	510	}
	511	return 0;
	512	}
	513
	514	double decrease (int index)
	515	{
	516	if ((index > 0) && (index <= STORAGE_SIZE)) {
	517	return storage[index - 1]--;
	518	} else {
	519	VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
	520	}
	521	return 0;
	522	}
	523
6ba1dd0f LM	524	void display (void)
	525	{
	526	int i;
	527	fprintf (stdout, "storage:");
	528	for (i = 0; i < STORAGE_SIZE; i++) {
	529	fprintf (stdout, " %g", storage[i]);
	530	}
	531	fprintf (stdout, "\n");
	532	}
	533
2a688642 LM	534	/* While do function */
	535
	536	double while_do (element_t cond, element_t action)
	537	{
	538	double ret = 0;
	539	element_t *temp = NULL;
	540
	541	VERBOSE (DEBUG, fprintf (stdout, "starting while loop\n"));
	542	if (cond == NULL) {
	543	return ret;
	544	}
	545	while (1) {
	546	VERBOSE (DEBUG, fprintf (stdout, "loop...\n"));
	547
	548	temp = dupelement (cond);
	549	if (!evaluate_element (temp, 0)) {
	550	break;
	551	}
	552	if (action) {
	553	temp = dupelement (action);
	554	ret = evaluate_element (temp, 0);
	555	}
	556	}
	557
	558	VERBOSE (DEBUG, fprintf (stdout, "ending while loop\n"));
	559
	560	return ret;
	561	}
	562
89cf0955 LM	563	/* quit function */
	564
	565	void quit (void)
	566	{
04d68907	567	fprintf (stdout, "bye\n");
89cf0955 LM	568	exit (0);
	569	}
	570
	571	/* help message */
	572
	573	void help (void)
	574	{
04d68907	575	fprintf (stdout, "calc is a simple calculator\n\n");
94b4e517 LM	576	fprintf (stdout, "supported operators:");
	577	fprintf (stdout, " + - * / %% ^\n");
	578	fprintf (stdout, "camparison operators:");
	579	fprintf (stdout, " == != >= <= > <\n");
	580	fprintf (stdout, "logical operators:");
	581	fprintf (stdout, " & \| !\n");
	582	fprintf (stdout, "supported functions:");
	583	fprintf (stdout, " pow sqrt cos sin atan log exp\n");
	584	fprintf (stdout, "storage functions:");
a8cf32ba	585	fprintf (stdout, " sto rcl inc dec\n");
94b4e517 LM	586	fprintf (stdout, "conditional functions:");
	587	fprintf (stdout, " cond\n");
	588	fprintf (stdout, "miscellaneous functions:");
	589	fprintf (stdout, " quit help\n");
	590	fprintf (stdout, "supported constants:");
471da7c9	591	fprintf (stdout, " e pi\n");
89cf0955	592	}
3b4b0bbe	593
f2927108 LM	594	/* evaluate element tree */
f2927108 LM	595
89cf0955 LM	596	#define MASK_SUB 0x1
	597	#define MASK_DIV 0x2
	598
3b4b0bbe	599	double evaluate_element (element_t *root, char mask)
f2927108 LM	600	{
f2927108 LM	601	double op0 = 0, op1 = 0;
3b4b0bbe	602	char nextmask = mask;
f2927108 LM	603
f2927108 LM	604	if ((root == NULL) \|\| (root == ERROR_OP)) {
04d68907	605	VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
f2927108 LM	606	return 0;
	607	}
	608
3b4b0bbe LM	609	/* mask to manage sub operator sub and div */
	610	switch (root->func) {
	611	case Add:
	612	nextmask &= ~MASK_SUB;
	613	nextmask &= ~MASK_DIV;
	614	break;
	615	case Sub:
	616	nextmask \|= MASK_SUB;
	617	nextmask &= ~MASK_DIV;
	618	break;
	619	case Mul:
	620	nextmask &= ~MASK_DIV;
	621	break;
	622	case Div:
	623	nextmask \|= MASK_DIV;
	624	break;
	625	default:
	626	nextmask = mask;
	627	}
	628
f2927108 LM	629	switch (root->func) {
f2927108 LM	630	case Val:
3b4b0bbe LM	631	case Sig:
3b4b0bbe LM	632	op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
f2927108 LM	633	break;
	634	case Add:
	635	case Sub:
	636	case Mul:
	637	case Div:
c47a9298	638	case Mod:
f2927108	639	case Pow:
3639df66	640	case Store:
7fe742c9 LM	641	case Equal:
	642	case Diff:
	643	case Ge:
	644	case Le:
	645	case Gt:
	646	case Lt:
ca3e2a2f LM	647	case And:
ca3e2a2f LM	648	case Or:
f2927108	649	if (root->ops[1]) {
3b4b0bbe	650	op1 = evaluate_element (root->ops[1], nextmask);
3639df66	651	} else if (root->func != Store) {
04d68907	652	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
f2927108 LM	653	return 0;
	654	}
	655	/* fallthrough */
	656	case Sqr:
	657	case Cos:
	658	case Sin:
471da7c9	659	case Atan:
f2927108 LM	660	case Log:
f2927108 LM	661	case Exp:
6ba1dd0f	662	case Recall:
a8cf32ba LM	663	case Inc:
a8cf32ba LM	664	case Dec:
ca3e2a2f	665	case Not:
94b4e517	666	case Cond:
f2927108	667	if (root->ops[0]) {
3b4b0bbe	668	op0 = evaluate_element (root->ops[0], 0);
f2927108	669	} else {
04d68907	670	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
f2927108 LM	671	return 0;
f2927108 LM	672	}
89cf0955	673	break;
6ba1dd0f	674	case Disp:
471da7c9 LM	675	case Quit:
471da7c9 LM	676	case Help:
5075f6ea	677	case Ans:
471da7c9 LM	678	case Pi:
471da7c9 LM	679	case E:
09d87cae	680	break;
2a688642	681	case While:
09d87cae LM	682	if (root->ops[0] == NULL) {
	683	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
	684	return 0;
	685	}
89cf0955	686	break;
f2927108 LM	687	}
	688
	689	switch (root->func) {
3b4b0bbe LM	690	case Val: return op0;
	691	case Sig: return -op0;
	692	case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
	693	case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
	694	case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
	695	case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
c47a9298	696	case Mod: return fmod (op0, op1);
f2927108 LM	697	case Pow: return pow (op0, op1);
	698	case Sqr: return sqrt (op0);
	699	case Cos: return cos (op0);
	700	case Sin: return sin (op0);
471da7c9	701	case Atan: return atan (op0);
f2927108 LM	702	case Log: return log (op0);
f2927108 LM	703	case Exp: return exp (op0);
3639df66	704	case Store: return store ((int)op0, (op1) ? op1 : answer);
6ba1dd0f	705	case Recall: return recall ((int)op0);
a8cf32ba LM	706	case Inc: return increase ((int)op0);
a8cf32ba LM	707	case Dec: return decrease ((int)op0);
6ba1dd0f	708	case Disp: display (); break;
471da7c9 LM	709	case Quit: quit (); break;
471da7c9 LM	710	case Help: help (); break;
5075f6ea	711	case Ans: return answer;
471da7c9 LM	712	case Pi: return M_PI;
471da7c9 LM	713	case E: return M_E;
7fe742c9 LM	714	case Equal: return op0 == op1;
	715	case Diff: return op0 != op1;
	716	case Ge: return op0 >= op1;
	717	case Le: return op0 <= op1;
	718	case Gt: return op0 > op1;
	719	case Lt: return op0 < op1;
ca3e2a2f LM	720	case And: return (op0 != 0) && (op1 != 0);
	721	case Or: return (op0 != 0) \|\| (op1 != 0);
	722	case Not: return (op0 == 0);
94b4e517 LM	723	case Cond:
	724	if ((op0) && (root->ops[1])) {
	725	return evaluate_element (root->ops[1], 0);
	726	} else if ((!op0) && (root->ops[2])) {
	727	return evaluate_element (root->ops[2], 0);
	728	} else {
	729	return 0;
	730	}
2a688642	731	case While: return while_do (root->ops[0], root->ops[1]);
f2927108 LM	732	}
	733
	734	return 0;
	735	}
	736
bc97a989	737	/* vim: set ts=4 sw=4 et: */