[calc.git] / parser.c

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

#include "debug.h"

#include "parser.h"

/* 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);
    }
}

/* functions */

#define NB_OPERATORS 6

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}
};

#define NB_FUNCTIONS 9
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", Atn, 1, 4, 5},
    { "exp",  Exp, 1, 3, 5},
    { "log",  Log, 1, 3, 5},
    { "quit", Qui, 0, 4, 5},
    { "help", Hel, 0, 4, 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] == 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 == 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 == ERROR_OP) || (*str == ',')) {
                    delelement (new);
                    delelement (root);
                    return ERROR_OP;
                }
                root->ops[0] = new;
            }
            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 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) {
                    new = newelement (Val, 1, 5);
                    if (new == NULL) {
                        return ERROR_OP;
                    }
                    new->value = value;
                    root = new;
                    str = pt;
                } else if (root->func == Val) {
                    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;
                    }
                } 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 Atn: func = "Arc Tangent"; break;
    case Log: func = "Logarithm"; break;
    case Exp: func = "Exponantial"; break;
    case Qui: func = "Quit"; break;
    case Hel: func = "Help"; 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);
        }
    }
}

/* 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:\n");
    fprintf (stdout, " + - * / %% ^\n\n");
    fprintf (stdout, "supported functions:\n");
    fprintf (stdout, " pow sqrt cos sin atan log exp\n\n");
    fprintf (stdout, "miscellaneous functions:\n");
    fprintf (stdout, " quit help\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:
        if (root->ops[1]) {
            op1 = evaluate_element (root->ops[1], nextmask);
        } else {
            VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
            return 0;
        }
        /* fallthrough */
    case Sqr:
    case Cos:
    case Sin:
    case Atn:
    case Log:
    case Exp:
        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 Qui:
    case Hel:
        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 Atn: return atan (op0);
    case Log: return log (op0);
    case Exp: return exp (op0);
    case Qui: quit (); break;
    case Hel: help (); break;
    }

    return 0;
}

/* vim: set ts=4 sw=4 et: */
Commit	Line	Data
bc97a989	1	#include <malloc.h>
f2927108	2	#include <math.h>
bc97a989 LM	3	#include <stdlib.h>
	4
	5	#include "debug.h"
bc97a989 LM	6
	7	#include "parser.h"
	8
	9	/* compare codes */
	10
	11	int codecmp (char ref, char str)
	12	{
	13	int sig;
	14
	15	while (*ref != '\0') {
0b9cc9b0 LM	16	if (*ref == '\t') {
	17	sig = (str == '.') ? -1 : ((str >= '0') && (*str <= '9'));
	18	} else {
	19	sig = str - ref;
	20	}
bc97a989 LM	21	if (sig != 0) {
	22	return (sig > 0) ? 1 : -1;
	23	}
0b9cc9b0 LM	24	str++;
0b9cc9b0 LM	25	ref++;
bc97a989 LM	26	}
	27
	28	return 0;
	29	}
	30
	31	/* allocate new element */
	32
11cda8d7	33	element_t *newelement (func_t function, int nbops, int prio)
bc97a989 LM	34	{
	35	element_t new = (element_t ) calloc (1, sizeof (element_t));
	36	if (new == NULL) {
04d68907	37	VERBOSE (ERROR, fprintf (stderr, "can't allocate memory\n"));
bc97a989 LM	38	return NULL;
	39	}
	40	new->func = function;
	41	new->nbops = nbops;
11cda8d7	42	new->prio = prio;
bc97a989 LM	43
	44	return new;
	45	}
	46
031d7bba LM	47	/* desallocate element */
	48
	49	void delelement (element_t *root)
	50	{
	51	int i;
	52	if ((root != NULL) && (root != ERROR_OP)) {
	53	for (i = 0; i < root->nbops; i++) {
	54	if ((root->ops[i] != NULL) && (root->ops[i] != ERROR_OP)) {
	55	delelement (root->ops[i]);
	56	}
	57	}
	58	free (root);
	59	}
	60	}
	61
bc97a989 LM	62	/* functions */
bc97a989 LM	63
c47a9298	64	#define NB_OPERATORS 6
bc97a989 LM	65
bc97a989 LM	66	keyword_t operators[NB_OPERATORS] = {
11cda8d7 LM	67	{ "+\t", Add, 2, 1, 1},
	68	{ "-\t", Sub, 2, 1, 1},
	69	{ "*", Mul, 2, 1, 2},
	70	{ "/", Div, 2, 1, 2},
c47a9298 LM	71	{ "%", Mod, 2, 1, 3},
c47a9298 LM	72	{ "^", Pow, 2, 1, 4}
bc97a989 LM	73	};
bc97a989 LM	74
89cf0955	75	#define NB_FUNCTIONS 9
bc97a989	76	keyword_t functions[NB_FUNCTIONS] = {
c47a9298 LM	77	{ "sqrt", Sqr, 1, 4, 5},
	78	{ "pow", Pow, 2, 3, 5},
	79	{ "cos", Cos, 1, 3, 5},
	80	{ "sin", Sin, 1, 3, 5},
	81	{ "atan", Atn, 1, 4, 5},
	82	{ "exp", Exp, 1, 3, 5},
89cf0955 LM	83	{ "log", Log, 1, 3, 5},
	84	{ "quit", Qui, 0, 4, 5},
	85	{ "help", Hel, 0, 4, 5}
bc97a989 LM	86	};
bc97a989 LM	87
d2ff8478 LM	88	/* subparser function */
	89
	90	element_t subparser (element_t proot, char *pstr, func_t func, int nbops, int prio)
	91	{
	92	element_t *new = newelement (func, nbops, prio);
	93	if (new == NULL) {
	94	return ERROR_OP;
	95	}
	96	new->ops[0] = *proot;
	97	new->ops[1] = parser (*pstr, pstr, new->prio);
	98	if (new->ops[1] == ERROR_OP) {
031d7bba LM	99	delelement (new);
031d7bba LM	100	*proot = NULL;
d2ff8478 LM	101	return ERROR_OP;
d2ff8478 LM	102	}
3b4b0bbe	103	*proot = newelement (Val, 1, 5);
031d7bba LM	104	if (*proot == NULL) {
031d7bba LM	105	delelement (new);
d2ff8478 LM	106	return ERROR_OP;
	107	}
	108	(*proot)->ops[0] = new;
	109
	110	return *proot;
	111	}
	112
bc97a989 LM	113	/* parser function */
bc97a989 LM	114
ef37d966	115	element_t parser (char str, char **next, int prio)
0b489a77	116	{
bc97a989	117	element_t *root = NULL;
85b4a72c	118	int i;
bc97a989	119
04d68907	120	VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));
49223129	121
bc97a989 LM	122	/* main loop */
	123	while (*str != '\0') {
	124	int found = 0;
	125	element_t *new = NULL;
04d68907	126	VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));
bc97a989 LM	127
	128	/* skip spaces and tabs */
	129
	130	if ((str == ' ') \|\| (str == '\t')) {
	131	str++;
	132	continue;
	133	}
	134
85b4a72c	135	/* check for open bracket */
0b489a77	136
0b489a77	137	if (*str == '(') {
04d68907	138	VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
0b489a77	139	if (root) {
85b4a72c LM	140	do {
85b4a72c LM	141	found = 0;
ef37d966	142	new = parser (str + 1, &str, 0);
85b4a72c	143	if (new == ERROR_OP) {
031d7bba	144	delelement (root);
85b4a72c LM	145	return ERROR_OP;
	146	}
	147	for (i = 0; i < root->nbops; i++) {
	148	if (root->ops[i] == NULL) {
0b489a77 LM	149	root->ops[i] = new;
	150	found = 1;
	151	break;
	152	}
	153	}
85b4a72c	154	if (!found) {
031d7bba LM	155	delelement (new);
031d7bba LM	156	delelement (root);
85b4a72c LM	157	return ERROR_OP;
	158	}
	159	} while (*str == ',');
	160	} else {
3b4b0bbe	161	root = newelement (Val, 1, 5);
85b4a72c	162	if (root == NULL) {
0b489a77 LM	163	return ERROR_OP;
0b489a77 LM	164	}
ef37d966	165	new = parser (str + 1, &str, 0);
85b4a72c	166	if ((new == ERROR_OP) \|\| (*str == ',')) {
031d7bba LM	167	delelement (new);
031d7bba LM	168	delelement (root);
efdfb543 LM	169	return ERROR_OP;
efdfb543 LM	170	}
85b4a72c	171	root->ops[0] = new;
0b489a77	172	}
85b4a72c	173	str++;
04d68907	174	VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
efdfb543	175	continue;
49223129	176	}
85b4a72c LM	177
	178	/* check for closing bracket or koma */
	179
	180	if ((str == ')') \|\| (str == ',')) {
49223129	181	if (next != NULL) {
85b4a72c	182	*next = str;
49223129 LM	183	}
49223129 LM	184	return root;
0b489a77 LM	185	}
0b489a77 LM	186
bc97a989 LM	187	/* look for operators */
	188
	189	for (i = 0; i < NB_OPERATORS; i++) {
	190	keyword_t *operator = operators + i;
	191	if (codecmp (operator->keyword, str) == 0) {
04d68907	192	VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
11cda8d7	193	if (root) {
ef37d966	194	if ((prio) && (prio > operator->prio)) {
04d68907	195	VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
ef37d966 LM	196	*next = str;
	197	return root;
	198	}
	199	str += operator->offset;
04d68907	200	VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
d2ff8478	201	if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
031d7bba	202	delelement (root);
ef37d966	203	return ERROR_OP;
11cda8d7	204	}
3b4b0bbe LM	205	} else if (*str == '-') {
	206	new = newelement (Sig, 1, 9);
	207	if (new == NULL) {
	208	return ERROR_OP;
	209	}
	210	root = new;
49223129	211	} else {
0b489a77	212	return ERROR_OP;
bc97a989	213	}
bc97a989	214	found = 1;
04d68907	215	VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
bc97a989 LM	216	break;
	217	}
	218	}
	219	if (found) {
bc97a989 LM	220	continue;
bc97a989 LM	221	}
49223129	222
bc97a989 LM	223	/* look for functions */
	224
	225	for (i = 0; i < NB_FUNCTIONS; i++) {
	226	keyword_t *function = functions + i;
	227	if (codecmp (function->keyword, str) == 0) {
04d68907	228	VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
bc97a989	229	if (root == NULL) {
04d68907	230	VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
11cda8d7	231	new = newelement (function->func, function->nbops, function->prio);
bc97a989	232	if (new == NULL) {
0b489a77	233	return ERROR_OP;
bc97a989 LM	234	}
bc97a989 LM	235	root = new;
031d7bba LM	236	} else {
031d7bba LM	237	delelement (root);
0b489a77	238	return ERROR_OP;
bc97a989 LM	239	}
	240	str += function->offset;
	241	found = 1;
04d68907	242	VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
bc97a989 LM	243	break;
	244	}
	245	}
	246	if (found) {
bc97a989 LM	247	continue;
	248	}
	249
bc97a989 LM	250	/* look for number */
bc97a989 LM	251
0b9cc9b0 LM	252	if (((str >= '0') && (str <= '9')) \|\|
0b9cc9b0 LM	253	(str == '.') \|\| (str == '+') \|\| (*str == '-')) {
04d68907	254	VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
bc97a989	255	char *pt;
fd88e359	256	double value = strtod (str, &pt);
04d68907	257	VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
bc97a989	258	if (str != pt) {
bc97a989	259	if (root == NULL) {
3b4b0bbe	260	new = newelement (Val, 1, 5);
c47a9298 LM	261	if (new == NULL) {
	262	return ERROR_OP;
	263	}
	264	new->value = value;
bc97a989	265	root = new;
c47a9298	266	str = pt;
0b9cc9b0 LM	267	} else if (root->func == Val) {
0b9cc9b0 LM	268	if ((str == '+') \|\| (str == '-')) {
c47a9298	269	if ((prio) && (prio > 1)) {
04d68907	270	VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
c47a9298 LM	271	*next = str;
	272	return root;
	273	}
d2ff8478	274	if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
031d7bba	275	delelement (root);
0b489a77 LM	276	return ERROR_OP;
0b489a77 LM	277	}
0b9cc9b0	278	} else {
031d7bba	279	delelement (root);
0b489a77	280	return ERROR_OP;
bc97a989	281	}
0b9cc9b0	282	} else {
031d7bba	283	delelement (root);
0b9cc9b0	284	return ERROR_OP;
bc97a989	285	}
bc97a989 LM	286	found = 1;
bc97a989 LM	287	}
04d68907	288	VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
bc97a989 LM	289	}
	290
	291	/* error */
	292
	293	if (!found) {
031d7bba	294	delelement (root);
0b489a77	295	return ERROR_OP;
bc97a989 LM	296	}
	297
	298	}
	299
49223129 LM	300	if (next != NULL) {
	301	*next = str;
	302	}
031d7bba	303
bc97a989 LM	304	return root;
	305	}
	306
	307	/* print element tree */
	308
	309	void print_element (element_t *root, int level)
	310	{
	311	char *func = NULL;
	312	int i;
	313
49223129	314	if ((root == NULL) \|\| (root == ERROR_OP)) {
bc97a989	315	return;
49223129 LM	316	}
49223129 LM	317
bc97a989	318	for (i = 0; i < level; i++) {
04d68907	319	fprintf (stdout, " ");
bc97a989 LM	320	}
	321
	322	switch (root->func) {
	323	case Val: func = "Value"; break;
89cf0955	324	case Sig: func = "Sign"; break;
bc97a989 LM	325	case Add: func = "Addition"; break;
	326	case Sub: func = "Subtraction"; break;
	327	case Mul: func = "Multiplication"; break;
	328	case Div: func = "Division"; break;
c47a9298	329	case Mod: func = "Modulo"; break;
bc97a989 LM	330	case Pow: func = "Power"; break;
	331	case Sqr: func = "Square Root"; break;
	332	case Cos: func = "Cosine"; break;
	333	case Sin: func = "Sine"; break;
	334	case Atn: func = "Arc Tangent"; break;
	335	case Log: func = "Logarithm"; break;
	336	case Exp: func = "Exponantial"; break;
89cf0955 LM	337	case Qui: func = "Quit"; break;
89cf0955 LM	338	case Hel: func = "Help"; break;
bc97a989 LM	339	}
bc97a989 LM	340
04d68907	341	fprintf (stdout, "Function: %s\n", func);
bc97a989	342
85b4a72c	343	if ((root->func == Val) && (root->ops[0] == NULL)) {
bc97a989	344	for (i = 0; i < level; i++) {
04d68907	345	fprintf (stdout, " ");
bc97a989	346	}
04d68907	347	fprintf (stdout, "value: %f\n", root->value);
bc97a989 LM	348	} else {
	349	for (i = 0; i < root->nbops; i++) {
	350	print_element (root->ops[i], level + 1);
	351	}
	352	}
	353	}
	354
89cf0955 LM	355	/* quit function */
	356
	357	void quit (void)
	358	{
04d68907	359	fprintf (stdout, "bye\n");
89cf0955 LM	360	exit (0);
	361	}
	362
	363	/* help message */
	364
	365	void help (void)
	366	{
04d68907 LM	367	fprintf (stdout, "calc is a simple calculator\n\n");
	368	fprintf (stdout, "supported operators:\n");
	369	fprintf (stdout, " + - * / %% ^\n\n");
	370	fprintf (stdout, "supported functions:\n");
	371	fprintf (stdout, " pow sqrt cos sin atan log exp\n\n");
	372	fprintf (stdout, "miscellaneous functions:\n");
	373	fprintf (stdout, " quit help\n");
89cf0955	374	}
3b4b0bbe	375
f2927108 LM	376	/* evaluate element tree */
f2927108 LM	377
89cf0955 LM	378	#define MASK_SUB 0x1
	379	#define MASK_DIV 0x2
	380
3b4b0bbe	381	double evaluate_element (element_t *root, char mask)
f2927108 LM	382	{
f2927108 LM	383	double op0 = 0, op1 = 0;
3b4b0bbe	384	char nextmask = mask;
f2927108 LM	385
f2927108 LM	386	if ((root == NULL) \|\| (root == ERROR_OP)) {
04d68907	387	VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
f2927108 LM	388	return 0;
	389	}
	390
3b4b0bbe LM	391	/* mask to manage sub operator sub and div */
	392	switch (root->func) {
	393	case Add:
	394	nextmask &= ~MASK_SUB;
	395	nextmask &= ~MASK_DIV;
	396	break;
	397	case Sub:
	398	nextmask \|= MASK_SUB;
	399	nextmask &= ~MASK_DIV;
	400	break;
	401	case Mul:
	402	nextmask &= ~MASK_DIV;
	403	break;
	404	case Div:
	405	nextmask \|= MASK_DIV;
	406	break;
	407	default:
	408	nextmask = mask;
	409	}
	410
f2927108 LM	411	switch (root->func) {
f2927108 LM	412	case Val:
3b4b0bbe LM	413	case Sig:
3b4b0bbe LM	414	op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
f2927108 LM	415	break;
	416	case Add:
	417	case Sub:
	418	case Mul:
	419	case Div:
c47a9298	420	case Mod:
f2927108 LM	421	case Pow:
f2927108 LM	422	if (root->ops[1]) {
3b4b0bbe	423	op1 = evaluate_element (root->ops[1], nextmask);
f2927108	424	} else {
04d68907	425	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
f2927108 LM	426	return 0;
	427	}
	428	/* fallthrough */
	429	case Sqr:
	430	case Cos:
	431	case Sin:
	432	case Atn:
	433	case Log:
	434	case Exp:
	435	if (root->ops[0]) {
3b4b0bbe	436	op0 = evaluate_element (root->ops[0], 0);
f2927108	437	} else {
04d68907	438	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
f2927108 LM	439	return 0;
f2927108 LM	440	}
89cf0955 LM	441	break;
	442	case Qui:
	443	case Hel:
	444	break;
f2927108 LM	445	}
	446
	447	switch (root->func) {
3b4b0bbe LM	448	case Val: return op0;
	449	case Sig: return -op0;
	450	case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
	451	case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
	452	case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
	453	case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
c47a9298	454	case Mod: return fmod (op0, op1);
f2927108 LM	455	case Pow: return pow (op0, op1);
	456	case Sqr: return sqrt (op0);
	457	case Cos: return cos (op0);
	458	case Sin: return sin (op0);
	459	case Atn: return atan (op0);
	460	case Log: return log (op0);
	461	case Exp: return exp (op0);
89cf0955 LM	462	case Qui: quit (); break;
89cf0955 LM	463	case Hel: help (); break;
f2927108 LM	464	}
	465
	466	return 0;
	467	}
	468
bc97a989	469	/* vim: set ts=4 sw=4 et: */