Flipper/Applications/Official/source-OLDER/kyhwana/calculator/tinyexpr.c

786 lines
21 KiB
C

// SPDX-License-Identifier: Zlib
/*
* TINYEXPR - Tiny recursive descent parser and evaluation engine in C
*
* Copyright (c) 2015-2020 Lewis Van Winkle
*
* http://CodePlea.com
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgement in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
/* COMPILE TIME OPTIONS */
/* Exponentiation associativity:
For a^b^c = (a^b)^c and -a^b = (-a)^b do nothing.
For a^b^c = a^(b^c) and -a^b = -(a^b) uncomment the next line.*/
/* #define TE_POW_FROM_RIGHT */
/* Logarithms
For log = base 10 log do nothing
For log = natural log uncomment the next line. */
/* #define TE_NAT_LOG */
#include "tinyexpr.h"
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <stdio.h>
#include <ctype.h>
#include <limits.h>
#ifndef NAN
#define NAN (0.0 / 0.0)
#endif
#ifndef INFINITY
#define INFINITY (1.0 / 0.0)
#endif
typedef double (*te_fun2)(double, double);
enum {
TOK_NULL = TE_CLOSURE7 + 1,
TOK_ERROR,
TOK_END,
TOK_SEP,
TOK_OPEN,
TOK_CLOSE,
TOK_NUMBER,
TOK_VARIABLE,
TOK_INFIX
};
enum { TE_CONSTANT = 1 };
typedef struct state {
const char* start;
const char* next;
int type;
union {
double value;
const double* bound;
const void* function;
};
void* context;
const te_variable* lookup;
int lookup_len;
} state;
#define TYPE_MASK(TYPE) ((TYPE)&0x0000001F)
#define IS_PURE(TYPE) (((TYPE)&TE_FLAG_PURE) != 0)
#define IS_FUNCTION(TYPE) (((TYPE)&TE_FUNCTION0) != 0)
#define IS_CLOSURE(TYPE) (((TYPE)&TE_CLOSURE0) != 0)
#define ARITY(TYPE) (((TYPE) & (TE_FUNCTION0 | TE_CLOSURE0)) ? ((TYPE)&0x00000007) : 0)
#define NEW_EXPR(type, ...) new_expr((type), (const te_expr*[]){__VA_ARGS__})
static te_expr* new_expr(const int type, const te_expr* parameters[]) {
const int arity = ARITY(type);
const int psize = sizeof(void*) * arity;
const int size =
(sizeof(te_expr) - sizeof(void*)) + psize + (IS_CLOSURE(type) ? sizeof(void*) : 0);
te_expr* ret = malloc(size);
memset(ret, 0, size);
if(arity && parameters) {
memcpy(ret->parameters, parameters, psize);
}
ret->type = type;
ret->bound = 0;
return ret;
}
void te_free_parameters(te_expr* n) {
if(!n) return;
switch(TYPE_MASK(n->type)) {
case TE_FUNCTION7:
case TE_CLOSURE7:
te_free(n->parameters[6]); /* Falls through. */
case TE_FUNCTION6:
case TE_CLOSURE6:
te_free(n->parameters[5]); /* Falls through. */
case TE_FUNCTION5:
case TE_CLOSURE5:
te_free(n->parameters[4]); /* Falls through. */
case TE_FUNCTION4:
case TE_CLOSURE4:
te_free(n->parameters[3]); /* Falls through. */
case TE_FUNCTION3:
case TE_CLOSURE3:
te_free(n->parameters[2]); /* Falls through. */
case TE_FUNCTION2:
case TE_CLOSURE2:
te_free(n->parameters[1]); /* Falls through. */
case TE_FUNCTION1:
case TE_CLOSURE1:
te_free(n->parameters[0]);
}
}
void te_free(te_expr* n) {
if(!n) return;
te_free_parameters(n);
free(n);
}
static double pi(void) {
return 3.14159265358979323846;
}
static double e(void) {
return 2.71828182845904523536;
}
static double fac(double a) { /* simplest version of fac */
if(a < 0) return NAN;
if(a > UINT_MAX) return INFINITY;
unsigned int ua = (unsigned int)(a);
unsigned long int result = 1, i;
for(i = 1; i <= ua; i++) {
if(i > ULONG_MAX / result) return INFINITY;
result *= i;
}
return (double)result;
}
static double ncr(double n, double r) {
if(n < 0 || r < 0 || n < r) return NAN;
if(n > UINT_MAX || r > UINT_MAX) return INFINITY;
unsigned long int un = (unsigned int)(n), ur = (unsigned int)(r), i;
unsigned long int result = 1;
if(ur > un / 2) ur = un - ur;
for(i = 1; i <= ur; i++) {
if(result > ULONG_MAX / (un - ur + i)) return INFINITY;
result *= un - ur + i;
result /= i;
}
return result;
}
static double npr(double n, double r) {
return ncr(n, r) * fac(r);
}
#ifdef _MSC_VER
#pragma function(ceil)
#pragma function(floor)
#endif
static const te_variable functions[] = {
/* must be in alphabetical order */
{"abs", fabs, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"acos", acos, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"asin", asin, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"atan", atan, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"atan2", atan2, TE_FUNCTION2 | TE_FLAG_PURE, 0},
{"ceil", ceil, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"cos", cos, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"cosh", cosh, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"e", e, TE_FUNCTION0 | TE_FLAG_PURE, 0},
{"exp", exp, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"fac", fac, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"floor", floor, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"ln", log, TE_FUNCTION1 | TE_FLAG_PURE, 0},
#ifdef TE_NAT_LOG
{"log", log, TE_FUNCTION1 | TE_FLAG_PURE, 0},
#else
{"log", log10, TE_FUNCTION1 | TE_FLAG_PURE, 0},
#endif
{"log10", log10, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"ncr", ncr, TE_FUNCTION2 | TE_FLAG_PURE, 0},
{"npr", npr, TE_FUNCTION2 | TE_FLAG_PURE, 0},
{"pi", pi, TE_FUNCTION0 | TE_FLAG_PURE, 0},
{"pow", pow, TE_FUNCTION2 | TE_FLAG_PURE, 0},
{"sin", sin, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"sinh", sinh, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"sqrt", sqrt, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"tan", tan, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{"tanh", tanh, TE_FUNCTION1 | TE_FLAG_PURE, 0},
{0, 0, 0, 0}};
static const te_variable* find_builtin(const char* name, int len) {
int imin = 0;
int imax = sizeof(functions) / sizeof(te_variable) - 2;
/*Binary search.*/
while(imax >= imin) {
const int i = (imin + ((imax - imin) / 2));
int c = strncmp(name, functions[i].name, len);
if(!c) c = '\0' - functions[i].name[len];
if(c == 0) {
return functions + i;
} else if(c > 0) {
imin = i + 1;
} else {
imax = i - 1;
}
}
return 0;
}
static const te_variable* find_lookup(const state* s, const char* name, int len) {
int iters;
const te_variable* var;
if(!s->lookup) return 0;
for(var = s->lookup, iters = s->lookup_len; iters; ++var, --iters) {
if(strncmp(name, var->name, len) == 0 && var->name[len] == '\0') {
return var;
}
}
return 0;
}
static double add(double a, double b) {
return a + b;
}
static double sub(double a, double b) {
return a - b;
}
static double mul(double a, double b) {
return a * b;
}
static double divide(double a, double b) {
return a / b;
}
static double negate(double a) {
return -a;
}
static double comma(double a, double b) {
(void)a;
return b;
}
void next_token(state* s) {
s->type = TOK_NULL;
do {
if(!*s->next) {
s->type = TOK_END;
return;
}
/* Try reading a number. */
if((s->next[0] >= '0' && s->next[0] <= '9') || s->next[0] == '.') {
s->value = strtof(s->next, (char**)&s->next);
s->type = TOK_NUMBER;
} else {
/* Look for a variable or builtin function call. */
if(isalpha(s->next[0])) {
const char* start;
start = s->next;
while(isalpha(s->next[0]) || isdigit(s->next[0]) || (s->next[0] == '_')) s->next++;
const te_variable* var = find_lookup(s, start, s->next - start);
if(!var) var = find_builtin(start, s->next - start);
if(!var) {
s->type = TOK_ERROR;
} else {
switch(TYPE_MASK(var->type)) {
case TE_VARIABLE:
s->type = TOK_VARIABLE;
s->bound = var->address;
break;
case TE_CLOSURE0:
case TE_CLOSURE1:
case TE_CLOSURE2:
case TE_CLOSURE3: /* Falls through. */
case TE_CLOSURE4:
case TE_CLOSURE5:
case TE_CLOSURE6:
case TE_CLOSURE7: /* Falls through. */
s->context = var->context; /* Falls through. */
case TE_FUNCTION0:
case TE_FUNCTION1:
case TE_FUNCTION2:
case TE_FUNCTION3: /* Falls through. */
case TE_FUNCTION4:
case TE_FUNCTION5:
case TE_FUNCTION6:
case TE_FUNCTION7: /* Falls through. */
s->type = var->type;
s->function = var->address;
break;
}
}
} else {
/* Look for an operator or special character. */
switch(s->next++[0]) {
case '+':
s->type = TOK_INFIX;
s->function = add;
break;
case '-':
s->type = TOK_INFIX;
s->function = sub;
break;
case '*':
s->type = TOK_INFIX;
s->function = mul;
break;
case '/':
s->type = TOK_INFIX;
s->function = divide;
break;
case '^':
s->type = TOK_INFIX;
s->function = pow;
break;
case '%':
s->type = TOK_INFIX;
s->function = fmod;
break;
case '(':
s->type = TOK_OPEN;
break;
case ')':
s->type = TOK_CLOSE;
break;
case ',':
s->type = TOK_SEP;
break;
case ' ':
case '\t':
case '\n':
case '\r':
break;
default:
s->type = TOK_ERROR;
break;
}
}
}
} while(s->type == TOK_NULL);
}
static te_expr* list(state* s);
static te_expr* expr(state* s);
static te_expr* power(state* s);
static te_expr* base(state* s) {
/* <base> = <constant> | <variable> | <function-0> {"(" ")"} | <function-1> <power> | <function-X> "(" <expr> {"," <expr>} ")" | "(" <list> ")" */
te_expr* ret;
int arity;
switch(TYPE_MASK(s->type)) {
case TOK_NUMBER:
ret = new_expr(TE_CONSTANT, 0);
ret->value = s->value;
next_token(s);
break;
case TOK_VARIABLE:
ret = new_expr(TE_VARIABLE, 0);
ret->bound = s->bound;
next_token(s);
break;
case TE_FUNCTION0:
case TE_CLOSURE0:
ret = new_expr(s->type, 0);
ret->function = s->function;
if(IS_CLOSURE(s->type)) ret->parameters[0] = s->context;
next_token(s);
if(s->type == TOK_OPEN) {
next_token(s);
if(s->type != TOK_CLOSE) {
s->type = TOK_ERROR;
} else {
next_token(s);
}
}
break;
case TE_FUNCTION1:
case TE_CLOSURE1:
ret = new_expr(s->type, 0);
ret->function = s->function;
if(IS_CLOSURE(s->type)) ret->parameters[1] = s->context;
next_token(s);
ret->parameters[0] = power(s);
break;
case TE_FUNCTION2:
case TE_FUNCTION3:
case TE_FUNCTION4:
case TE_FUNCTION5:
case TE_FUNCTION6:
case TE_FUNCTION7:
case TE_CLOSURE2:
case TE_CLOSURE3:
case TE_CLOSURE4:
case TE_CLOSURE5:
case TE_CLOSURE6:
case TE_CLOSURE7:
arity = ARITY(s->type);
ret = new_expr(s->type, 0);
ret->function = s->function;
if(IS_CLOSURE(s->type)) ret->parameters[arity] = s->context;
next_token(s);
if(s->type != TOK_OPEN) {
s->type = TOK_ERROR;
} else {
int i;
for(i = 0; i < arity; i++) {
next_token(s);
ret->parameters[i] = expr(s);
if(s->type != TOK_SEP) {
break;
}
}
if(s->type != TOK_CLOSE || i != arity - 1) {
s->type = TOK_ERROR;
} else {
next_token(s);
}
}
break;
case TOK_OPEN:
next_token(s);
ret = list(s);
if(s->type != TOK_CLOSE) {
s->type = TOK_ERROR;
} else {
next_token(s);
}
break;
default:
ret = new_expr(0, 0);
s->type = TOK_ERROR;
ret->value = NAN;
break;
}
return ret;
}
static te_expr* power(state* s) {
/* <power> = {("-" | "+")} <base> */
int sign = 1;
while(s->type == TOK_INFIX && (s->function == add || s->function == sub)) {
if(s->function == sub) sign = -sign;
next_token(s);
}
te_expr* ret;
if(sign == 1) {
ret = base(s);
} else {
ret = NEW_EXPR(TE_FUNCTION1 | TE_FLAG_PURE, base(s));
ret->function = negate;
}
return ret;
}
#ifdef TE_POW_FROM_RIGHT
static te_expr* factor(state* s) {
/* <factor> = <power> {"^" <power>} */
te_expr* ret = power(s);
int neg = 0;
if(ret->type == (TE_FUNCTION1 | TE_FLAG_PURE) && ret->function == negate) {
te_expr* se = ret->parameters[0];
free(ret);
ret = se;
neg = 1;
}
te_expr* insertion = 0;
while(s->type == TOK_INFIX && (s->function == pow)) {
te_fun2 t = s->function;
next_token(s);
if(insertion) {
/* Make exponentiation go right-to-left. */
te_expr* insert =
NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, insertion->parameters[1], power(s));
insert->function = t;
insertion->parameters[1] = insert;
insertion = insert;
} else {
ret = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, ret, power(s));
ret->function = t;
insertion = ret;
}
}
if(neg) {
ret = NEW_EXPR(TE_FUNCTION1 | TE_FLAG_PURE, ret);
ret->function = negate;
}
return ret;
}
#else
static te_expr* factor(state* s) {
/* <factor> = <power> {"^" <power>} */
te_expr* ret = power(s);
while(s->type == TOK_INFIX && (s->function == pow)) {
te_fun2 t = s->function;
next_token(s);
ret = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, ret, power(s));
ret->function = t;
}
return ret;
}
#endif
static te_expr* term(state* s) {
/* <term> = <factor> {("*" | "/" | "%") <factor>} */
te_expr* ret = factor(s);
while(s->type == TOK_INFIX &&
(s->function == mul || s->function == divide || s->function == fmod)) {
te_fun2 t = s->function;
next_token(s);
ret = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, ret, factor(s));
ret->function = t;
}
return ret;
}
static te_expr* expr(state* s) {
/* <expr> = <term> {("+" | "-") <term>} */
te_expr* ret = term(s);
while(s->type == TOK_INFIX && (s->function == add || s->function == sub)) {
te_fun2 t = s->function;
next_token(s);
ret = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, ret, term(s));
ret->function = t;
}
return ret;
}
static te_expr* list(state* s) {
/* <list> = <expr> {"," <expr>} */
te_expr* ret = expr(s);
while(s->type == TOK_SEP) {
next_token(s);
ret = NEW_EXPR(TE_FUNCTION2 | TE_FLAG_PURE, ret, expr(s));
ret->function = comma;
}
return ret;
}
#define TE_FUN(...) ((double (*)(__VA_ARGS__))n->function)
#define M(e) te_eval(n->parameters[e])
double te_eval(const te_expr* n) {
if(!n) return NAN;
switch(TYPE_MASK(n->type)) {
case TE_CONSTANT:
return n->value;
case TE_VARIABLE:
return *n->bound;
case TE_FUNCTION0:
case TE_FUNCTION1:
case TE_FUNCTION2:
case TE_FUNCTION3:
case TE_FUNCTION4:
case TE_FUNCTION5:
case TE_FUNCTION6:
case TE_FUNCTION7:
switch(ARITY(n->type)) {
case 0:
return TE_FUN(void)();
case 1:
return TE_FUN(double)(M(0));
case 2:
return TE_FUN(double, double)(M(0), M(1));
case 3:
return TE_FUN(double, double, double)(M(0), M(1), M(2));
case 4:
return TE_FUN(double, double, double, double)(M(0), M(1), M(2), M(3));
case 5:
return TE_FUN(double, double, double, double, double)(M(0), M(1), M(2), M(3), M(4));
case 6:
return TE_FUN(double, double, double, double, double, double)(
M(0), M(1), M(2), M(3), M(4), M(5));
case 7:
return TE_FUN(double, double, double, double, double, double, double)(
M(0), M(1), M(2), M(3), M(4), M(5), M(6));
default:
return NAN;
}
case TE_CLOSURE0:
case TE_CLOSURE1:
case TE_CLOSURE2:
case TE_CLOSURE3:
case TE_CLOSURE4:
case TE_CLOSURE5:
case TE_CLOSURE6:
case TE_CLOSURE7:
switch(ARITY(n->type)) {
case 0:
return TE_FUN(void*)(n->parameters[0]);
case 1:
return TE_FUN(void*, double)(n->parameters[1], M(0));
case 2:
return TE_FUN(void*, double, double)(n->parameters[2], M(0), M(1));
case 3:
return TE_FUN(void*, double, double, double)(n->parameters[3], M(0), M(1), M(2));
case 4:
return TE_FUN(void*, double, double, double, double)(
n->parameters[4], M(0), M(1), M(2), M(3));
case 5:
return TE_FUN(void*, double, double, double, double, double)(
n->parameters[5], M(0), M(1), M(2), M(3), M(4));
case 6:
return TE_FUN(void*, double, double, double, double, double, double)(
n->parameters[6], M(0), M(1), M(2), M(3), M(4), M(5));
case 7:
return TE_FUN(void*, double, double, double, double, double, double, double)(
n->parameters[7], M(0), M(1), M(2), M(3), M(4), M(5), M(6));
default:
return NAN;
}
default:
return NAN;
}
}
#undef TE_FUN
#undef M
static void optimize(te_expr* n) {
/* Evaluates as much as possible. */
if(n->type == TE_CONSTANT) return;
if(n->type == TE_VARIABLE) return;
/* Only optimize out functions flagged as pure. */
if(IS_PURE(n->type)) {
const int arity = ARITY(n->type);
int known = 1;
int i;
for(i = 0; i < arity; ++i) {
optimize(n->parameters[i]);
if(((te_expr*)(n->parameters[i]))->type != TE_CONSTANT) {
known = 0;
}
}
if(known) {
const double value = te_eval(n);
te_free_parameters(n);
n->type = TE_CONSTANT;
n->value = value;
}
}
}
te_expr*
te_compile(const char* expression, const te_variable* variables, int var_count, int* error) {
state s;
s.start = s.next = expression;
s.lookup = variables;
s.lookup_len = var_count;
next_token(&s);
te_expr* root = list(&s);
if(s.type != TOK_END) {
te_free(root);
if(error) {
*error = (s.next - s.start);
if(*error == 0) *error = 1;
}
return 0;
} else {
optimize(root);
if(error) *error = 0;
return root;
}
}
double te_interp(const char* expression, int* error) {
te_expr* n = te_compile(expression, 0, 0, error);
double ret;
if(n) {
ret = te_eval(n);
te_free(n);
} else {
ret = NAN;
}
return ret;
}
static void pn(const te_expr* n, int depth) {
int i, arity;
printf("%*s", depth, "");
switch(TYPE_MASK(n->type)) {
case TE_CONSTANT:
printf("%f\n", n->value);
break;
case TE_VARIABLE:
printf("bound %p\n", n->bound);
break;
case TE_FUNCTION0:
case TE_FUNCTION1:
case TE_FUNCTION2:
case TE_FUNCTION3:
case TE_FUNCTION4:
case TE_FUNCTION5:
case TE_FUNCTION6:
case TE_FUNCTION7:
case TE_CLOSURE0:
case TE_CLOSURE1:
case TE_CLOSURE2:
case TE_CLOSURE3:
case TE_CLOSURE4:
case TE_CLOSURE5:
case TE_CLOSURE6:
case TE_CLOSURE7:
arity = ARITY(n->type);
printf("f%d", arity);
for(i = 0; i < arity; i++) {
printf(" %p", n->parameters[i]);
}
printf("\n");
for(i = 0; i < arity; i++) {
pn(n->parameters[i], depth + 1);
}
break;
}
}
void te_print(const te_expr* n) {
pn(n, 0);
}