[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);
    }
}

/* 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 12
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, 1, 3, 5},
    { "rcl",  Recall, 1, 3, 5},
    { "disp",  Disp, 0, 4, 5},
    { "quit", Quit, 0, 4, 5},
    { "help", Help, 0, 4, 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] == 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 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) {
                    new = newelement (Val, 1, 5);
                    if (new == NULL) {
                        return ERROR_OP;
                    }
                    new->value = value;
                    root = new;
                    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 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;
    }

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

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;
}

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

/* 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, "storage functions:\n");
    fprintf (stdout, " sto rcl\n\n");
    fprintf (stdout, "miscellaneous functions:\n");
    fprintf (stdout, " quit help\n\n");
    fprintf (stdout, "supported constants:\n");
    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:
        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 Atan:
    case Log:
    case Exp:
    case Store:
    case Recall:
        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;
    }

    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);
    case Recall: return recall ((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;
    }

    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
bc97a989 LM	70	/* functions */
bc97a989 LM	71
c47a9298	72	#define NB_OPERATORS 6
bc97a989 LM	73
bc97a989 LM	74	keyword_t operators[NB_OPERATORS] = {
11cda8d7 LM	75	{ "+\t", Add, 2, 1, 1},
	76	{ "-\t", Sub, 2, 1, 1},
	77	{ "*", Mul, 2, 1, 2},
	78	{ "/", Div, 2, 1, 2},
c47a9298 LM	79	{ "%", Mod, 2, 1, 3},
c47a9298 LM	80	{ "^", Pow, 2, 1, 4}
bc97a989 LM	81	};
bc97a989 LM	82
6ba1dd0f	83	#define NB_FUNCTIONS 12
bc97a989	84	keyword_t functions[NB_FUNCTIONS] = {
c47a9298 LM	85	{ "sqrt", Sqr, 1, 4, 5},
	86	{ "pow", Pow, 2, 3, 5},
	87	{ "cos", Cos, 1, 3, 5},
	88	{ "sin", Sin, 1, 3, 5},
471da7c9	89	{ "atan", Atan, 1, 4, 5},
c47a9298	90	{ "exp", Exp, 1, 3, 5},
89cf0955	91	{ "log", Log, 1, 3, 5},
6ba1dd0f LM	92	{ "sto", Store, 1, 3, 5},
	93	{ "rcl", Recall, 1, 3, 5},
	94	{ "disp", Disp, 0, 4, 5},
471da7c9 LM	95	{ "quit", Quit, 0, 4, 5},
	96	{ "help", Help, 0, 4, 5}
	97	};
	98
5075f6ea	99	#define NB_CONSTANTS 3
471da7c9	100	keyword_t constants[NB_CONSTANTS] = {
5075f6ea LM	101	{ "ans", Ans, 0, 3, 5},
	102	{ "e", E, 0, 1, 5},
	103	{ "pi", Pi, 0, 2, 5}
bc97a989 LM	104	};
bc97a989 LM	105
d2ff8478 LM	106	/* subparser function */
	107
	108	element_t subparser (element_t proot, char *pstr, func_t func, int nbops, int prio)
	109	{
	110	element_t *new = newelement (func, nbops, prio);
	111	if (new == NULL) {
	112	return ERROR_OP;
	113	}
	114	new->ops[0] = *proot;
	115	new->ops[1] = parser (*pstr, pstr, new->prio);
	116	if (new->ops[1] == ERROR_OP) {
031d7bba LM	117	delelement (new);
031d7bba LM	118	*proot = NULL;
d2ff8478 LM	119	return ERROR_OP;
d2ff8478 LM	120	}
3b4b0bbe	121	*proot = newelement (Val, 1, 5);
031d7bba LM	122	if (*proot == NULL) {
031d7bba LM	123	delelement (new);
d2ff8478 LM	124	return ERROR_OP;
	125	}
	126	(*proot)->ops[0] = new;
	127
	128	return *proot;
	129	}
	130
bc97a989 LM	131	/* parser function */
bc97a989 LM	132
ef37d966	133	element_t parser (char str, char **next, int prio)
0b489a77	134	{
bc97a989	135	element_t *root = NULL;
85b4a72c	136	int i;
bc97a989	137
04d68907	138	VERBOSE (DEBUG, fprintf (stdout, "Starting parsing\n"));
49223129	139
bc97a989 LM	140	/* main loop */
	141	while (*str != '\0') {
	142	int found = 0;
	143	element_t *new = NULL;
04d68907	144	VERBOSE (INFO, fprintf (stdout, "Processing: %s\n", str));
bc97a989 LM	145
	146	/* skip spaces and tabs */
	147
	148	if ((str == ' ') \|\| (str == '\t')) {
	149	str++;
	150	continue;
	151	}
	152
85b4a72c	153	/* check for open bracket */
0b489a77	154
0b489a77	155	if (*str == '(') {
04d68907	156	VERBOSE (DEBUG, fprintf (stdout, "start processing bracket\n"));
0b489a77	157	if (root) {
85b4a72c LM	158	do {
85b4a72c LM	159	found = 0;
ef37d966	160	new = parser (str + 1, &str, 0);
85b4a72c	161	if (new == ERROR_OP) {
031d7bba	162	delelement (root);
85b4a72c LM	163	return ERROR_OP;
	164	}
	165	for (i = 0; i < root->nbops; i++) {
	166	if (root->ops[i] == NULL) {
0b489a77 LM	167	root->ops[i] = new;
	168	found = 1;
	169	break;
	170	}
	171	}
85b4a72c	172	if (!found) {
031d7bba LM	173	delelement (new);
031d7bba LM	174	delelement (root);
85b4a72c LM	175	return ERROR_OP;
	176	}
	177	} while (*str == ',');
	178	} else {
3b4b0bbe	179	root = newelement (Val, 1, 5);
85b4a72c	180	if (root == NULL) {
0b489a77 LM	181	return ERROR_OP;
0b489a77 LM	182	}
ef37d966	183	new = parser (str + 1, &str, 0);
85b4a72c	184	if ((new == ERROR_OP) \|\| (*str == ',')) {
031d7bba LM	185	delelement (new);
031d7bba LM	186	delelement (root);
efdfb543 LM	187	return ERROR_OP;
efdfb543 LM	188	}
85b4a72c	189	root->ops[0] = new;
0b489a77	190	}
85b4a72c	191	str++;
04d68907	192	VERBOSE (DEBUG, fprintf (stdout, "stop processing bracket\n"));
efdfb543	193	continue;
49223129	194	}
85b4a72c LM	195
	196	/* check for closing bracket or koma */
	197
	198	if ((str == ')') \|\| (str == ',')) {
49223129	199	if (next != NULL) {
85b4a72c	200	*next = str;
49223129 LM	201	}
49223129 LM	202	return root;
0b489a77 LM	203	}
0b489a77 LM	204
bc97a989 LM	205	/* look for operators */
	206
	207	for (i = 0; i < NB_OPERATORS; i++) {
	208	keyword_t *operator = operators + i;
	209	if (codecmp (operator->keyword, str) == 0) {
04d68907	210	VERBOSE (DEBUG, fprintf (stdout, "start processing operator\n"));
11cda8d7	211	if (root) {
ef37d966	212	if ((prio) && (prio > operator->prio)) {
04d68907	213	VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
ef37d966 LM	214	*next = str;
	215	return root;
	216	}
	217	str += operator->offset;
04d68907	218	VERBOSE (INFO, fprintf (stdout, "Oper: %d\n", operator->func));
d2ff8478	219	if (subparser (&root, &str, operator->func, operator->nbops, operator->prio) == ERROR_OP) {
031d7bba	220	delelement (root);
ef37d966	221	return ERROR_OP;
11cda8d7	222	}
3b4b0bbe LM	223	} else if (*str == '-') {
	224	new = newelement (Sig, 1, 9);
	225	if (new == NULL) {
	226	return ERROR_OP;
	227	}
	228	root = new;
49223129	229	} else {
0b489a77	230	return ERROR_OP;
bc97a989	231	}
bc97a989	232	found = 1;
04d68907	233	VERBOSE (DEBUG, fprintf (stdout, "stop processing operator\n"));
bc97a989 LM	234	break;
	235	}
	236	}
	237	if (found) {
bc97a989 LM	238	continue;
bc97a989 LM	239	}
49223129	240
bc97a989 LM	241	/* look for functions */
	242
	243	for (i = 0; i < NB_FUNCTIONS; i++) {
	244	keyword_t *function = functions + i;
	245	if (codecmp (function->keyword, str) == 0) {
04d68907	246	VERBOSE (DEBUG, fprintf (stdout, "start processing function\n"));
bc97a989	247	if (root == NULL) {
04d68907	248	VERBOSE (INFO, fprintf (stdout, "Func: %d\n", function->func));
11cda8d7	249	new = newelement (function->func, function->nbops, function->prio);
bc97a989	250	if (new == NULL) {
0b489a77	251	return ERROR_OP;
bc97a989 LM	252	}
bc97a989 LM	253	root = new;
031d7bba LM	254	} else {
031d7bba LM	255	delelement (root);
0b489a77	256	return ERROR_OP;
bc97a989 LM	257	}
	258	str += function->offset;
	259	found = 1;
04d68907	260	VERBOSE (DEBUG, fprintf (stdout, "stop processing function\n"));
bc97a989 LM	261	break;
	262	}
	263	}
	264	if (found) {
bc97a989 LM	265	continue;
	266	}
	267
471da7c9 LM	268	/* look for constant */
	269
	270	for (i = 0; i < NB_CONSTANTS; i++) {
	271	keyword_t *constant = constants + i;
	272	if (codecmp (constant->keyword, str) == 0) {
	273	VERBOSE (DEBUG, fprintf (stdout, "start processing constant\n"));
	274	if (root == NULL) {
5075f6ea	275	VERBOSE (INFO, fprintf (stdout, "Const: %d\n", constant->func));
471da7c9 LM	276	new = newelement (constant->func, constant->nbops, constant->prio);
	277	if (new == NULL) {
	278	return ERROR_OP;
	279	}
	280	root = new;
	281	} else {
	282	delelement (root);
	283	return ERROR_OP;
	284	}
	285	str += constant->offset;
	286	found = 1;
	287	VERBOSE (DEBUG, fprintf (stdout, "stop processing constant\n"));
	288	break;
	289	}
	290	}
	291	if (found) {
	292	continue;
	293	}
	294
bc97a989 LM	295	/* look for number */
bc97a989 LM	296
0b9cc9b0 LM	297	if (((str >= '0') && (str <= '9')) \|\|
0b9cc9b0 LM	298	(str == '.') \|\| (str == '+') \|\| (*str == '-')) {
04d68907	299	VERBOSE (DEBUG, fprintf (stdout, "start processing value\n"));
bc97a989	300	char *pt;
fd88e359	301	double value = strtod (str, &pt);
04d68907	302	VERBOSE (INFO, fprintf (stdout, "Value: %f\n", value));
bc97a989	303	if (str != pt) {
bc97a989	304	if (root == NULL) {
3b4b0bbe	305	new = newelement (Val, 1, 5);
c47a9298 LM	306	if (new == NULL) {
	307	return ERROR_OP;
	308	}
	309	new->value = value;
bc97a989	310	root = new;
c47a9298	311	str = pt;
32741902 LM	312	} else if ((str == '+') \|\| (str == '-')) {
	313	if ((prio) && (prio > 1)) {
	314	VERBOSE (DEBUG, fprintf (stdout, "stop because operator priority\n"));
	315	*next = str;
	316	return root;
	317	}
	318	if (subparser (&root, &str, Add, 2, 1) == ERROR_OP) {
031d7bba	319	delelement (root);
0b489a77	320	return ERROR_OP;
bc97a989	321	}
0b9cc9b0	322	} else {
031d7bba	323	delelement (root);
0b9cc9b0	324	return ERROR_OP;
bc97a989	325	}
bc97a989 LM	326	found = 1;
bc97a989 LM	327	}
04d68907	328	VERBOSE (DEBUG, fprintf (stdout, "stop processing value\n"));
bc97a989 LM	329	}
	330
	331	/* error */
	332
	333	if (!found) {
031d7bba	334	delelement (root);
0b489a77	335	return ERROR_OP;
bc97a989 LM	336	}
	337
	338	}
	339
49223129 LM	340	if (next != NULL) {
	341	*next = str;
	342	}
031d7bba	343
bc97a989 LM	344	return root;
	345	}
	346
	347	/* print element tree */
	348
	349	void print_element (element_t *root, int level)
	350	{
	351	char *func = NULL;
	352	int i;
	353
49223129	354	if ((root == NULL) \|\| (root == ERROR_OP)) {
bc97a989	355	return;
49223129 LM	356	}
49223129 LM	357
bc97a989	358	for (i = 0; i < level; i++) {
04d68907	359	fprintf (stdout, " ");
bc97a989 LM	360	}
	361
	362	switch (root->func) {
	363	case Val: func = "Value"; break;
89cf0955	364	case Sig: func = "Sign"; break;
bc97a989 LM	365	case Add: func = "Addition"; break;
	366	case Sub: func = "Subtraction"; break;
	367	case Mul: func = "Multiplication"; break;
	368	case Div: func = "Division"; break;
c47a9298	369	case Mod: func = "Modulo"; break;
bc97a989 LM	370	case Pow: func = "Power"; break;
	371	case Sqr: func = "Square Root"; break;
	372	case Cos: func = "Cosine"; break;
	373	case Sin: func = "Sine"; break;
471da7c9	374	case Atan: func = "Arc Tangent"; break;
bc97a989 LM	375	case Log: func = "Logarithm"; break;
bc97a989 LM	376	case Exp: func = "Exponantial"; break;
6ba1dd0f LM	377	case Store: func = "Store"; break;
	378	case Recall: func = "Recall"; break;
	379	case Disp: func = "Display"; break;
471da7c9 LM	380	case Quit: func = "Quit"; break;
471da7c9 LM	381	case Help: func = "Help"; break;
5075f6ea	382	case Ans: func = "Ans"; break;
471da7c9 LM	383	case Pi: func = "Pi"; break;
471da7c9 LM	384	case E: func = "E"; break;
bc97a989 LM	385	}
bc97a989 LM	386
04d68907	387	fprintf (stdout, "Function: %s\n", func);
bc97a989	388
85b4a72c	389	if ((root->func == Val) && (root->ops[0] == NULL)) {
bc97a989	390	for (i = 0; i < level; i++) {
04d68907	391	fprintf (stdout, " ");
bc97a989	392	}
04d68907	393	fprintf (stdout, "value: %f\n", root->value);
bc97a989 LM	394	} else {
	395	for (i = 0; i < root->nbops; i++) {
	396	print_element (root->ops[i], level + 1);
	397	}
	398	}
	399	}
	400
6ba1dd0f LM	401	/* storage functions */
	402
	403	double store (int index)
	404	{
	405	if ((index > 0) && (index <= STORAGE_SIZE)) {
	406	storage[index - 1] = answer;
	407	} else {
	408	VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
	409	}
	410	return answer;
	411	}
	412
	413	double recall (int index)
	414	{
	415	if ((index > 0) && (index <= STORAGE_SIZE)) {
	416	return storage[index - 1];
	417	} else {
	418	VERBOSE (WARNING, fprintf (stdout, "invalid index (%d) [1, %d]\n", index, STORAGE_SIZE));
	419	}
	420	return 0;
	421	}
	422
	423	void display (void)
	424	{
	425	int i;
	426	fprintf (stdout, "storage:");
	427	for (i = 0; i < STORAGE_SIZE; i++) {
	428	fprintf (stdout, " %g", storage[i]);
	429	}
	430	fprintf (stdout, "\n");
	431	}
	432
89cf0955 LM	433	/* quit function */
	434
	435	void quit (void)
	436	{
04d68907	437	fprintf (stdout, "bye\n");
89cf0955 LM	438	exit (0);
	439	}
	440
	441	/* help message */
	442
	443	void help (void)
	444	{
04d68907 LM	445	fprintf (stdout, "calc is a simple calculator\n\n");
	446	fprintf (stdout, "supported operators:\n");
	447	fprintf (stdout, " + - * / %% ^\n\n");
	448	fprintf (stdout, "supported functions:\n");
	449	fprintf (stdout, " pow sqrt cos sin atan log exp\n\n");
6ba1dd0f LM	450	fprintf (stdout, "storage functions:\n");
6ba1dd0f LM	451	fprintf (stdout, " sto rcl\n\n");
04d68907	452	fprintf (stdout, "miscellaneous functions:\n");
471da7c9 LM	453	fprintf (stdout, " quit help\n\n");
	454	fprintf (stdout, "supported constants:\n");
	455	fprintf (stdout, " e pi\n");
89cf0955	456	}
3b4b0bbe	457
f2927108 LM	458	/* evaluate element tree */
f2927108 LM	459
89cf0955 LM	460	#define MASK_SUB 0x1
	461	#define MASK_DIV 0x2
	462
3b4b0bbe	463	double evaluate_element (element_t *root, char mask)
f2927108 LM	464	{
f2927108 LM	465	double op0 = 0, op1 = 0;
3b4b0bbe	466	char nextmask = mask;
f2927108 LM	467
f2927108 LM	468	if ((root == NULL) \|\| (root == ERROR_OP)) {
04d68907	469	VERBOSE (WARNING, fprintf (stdout, "error while evaluating\n"));
f2927108 LM	470	return 0;
	471	}
	472
3b4b0bbe LM	473	/* mask to manage sub operator sub and div */
	474	switch (root->func) {
	475	case Add:
	476	nextmask &= ~MASK_SUB;
	477	nextmask &= ~MASK_DIV;
	478	break;
	479	case Sub:
	480	nextmask \|= MASK_SUB;
	481	nextmask &= ~MASK_DIV;
	482	break;
	483	case Mul:
	484	nextmask &= ~MASK_DIV;
	485	break;
	486	case Div:
	487	nextmask \|= MASK_DIV;
	488	break;
	489	default:
	490	nextmask = mask;
	491	}
	492
f2927108 LM	493	switch (root->func) {
f2927108 LM	494	case Val:
3b4b0bbe LM	495	case Sig:
3b4b0bbe LM	496	op0 = (root->ops[0]) ? evaluate_element (root->ops[0], nextmask) : root->value;
f2927108 LM	497	break;
	498	case Add:
	499	case Sub:
	500	case Mul:
	501	case Div:
c47a9298	502	case Mod:
f2927108 LM	503	case Pow:
f2927108 LM	504	if (root->ops[1]) {
3b4b0bbe	505	op1 = evaluate_element (root->ops[1], nextmask);
f2927108	506	} else {
04d68907	507	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[1])\n"));
f2927108 LM	508	return 0;
	509	}
	510	/* fallthrough */
	511	case Sqr:
	512	case Cos:
	513	case Sin:
471da7c9	514	case Atan:
f2927108 LM	515	case Log:
f2927108 LM	516	case Exp:
6ba1dd0f LM	517	case Store:
6ba1dd0f LM	518	case Recall:
f2927108	519	if (root->ops[0]) {
3b4b0bbe	520	op0 = evaluate_element (root->ops[0], 0);
f2927108	521	} else {
04d68907	522	VERBOSE (WARNING, fprintf (stdout, "error while evaluating (op[0])\n"));
f2927108 LM	523	return 0;
f2927108 LM	524	}
89cf0955	525	break;
6ba1dd0f	526	case Disp:
471da7c9 LM	527	case Quit:
471da7c9 LM	528	case Help:
5075f6ea	529	case Ans:
471da7c9 LM	530	case Pi:
471da7c9 LM	531	case E:
89cf0955	532	break;
f2927108 LM	533	}
	534
	535	switch (root->func) {
3b4b0bbe LM	536	case Val: return op0;
	537	case Sig: return -op0;
	538	case Add: return ((mask & MASK_SUB) == 0) ? op0 + op1 : op0 - op1;
	539	case Sub: return ((mask & MASK_SUB) == 0) ? op0 - op1 : op0 + op1;
	540	case Mul: return ((mask & MASK_DIV) == 0) ? op0 * op1 : op0 / op1;
	541	case Div: return ((mask & MASK_DIV) == 0) ? op0 / op1 : op0 * op1;
c47a9298	542	case Mod: return fmod (op0, op1);
f2927108 LM	543	case Pow: return pow (op0, op1);
	544	case Sqr: return sqrt (op0);
	545	case Cos: return cos (op0);
	546	case Sin: return sin (op0);
471da7c9	547	case Atan: return atan (op0);
f2927108 LM	548	case Log: return log (op0);
f2927108 LM	549	case Exp: return exp (op0);
6ba1dd0f LM	550	case Store: return store ((int)op0);
	551	case Recall: return recall ((int)op0);
	552	case Disp: display (); break;
471da7c9 LM	553	case Quit: quit (); break;
471da7c9 LM	554	case Help: help (); break;
5075f6ea	555	case Ans: return answer;
471da7c9 LM	556	case Pi: return M_PI;
471da7c9 LM	557	case E: return M_E;
f2927108 LM	558	}
	559
	560	return 0;
	561	}
	562
bc97a989	563	/* vim: set ts=4 sw=4 et: */