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Added comma operator, builtin functions of arity 0 and 2.

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This commit is contained in:
Lewis Van Winkle
2016-02-23 15:18:44 -06:00
parent 5ad50341ec
commit 52a4995d6c
3 changed files with 132 additions and 39 deletions
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9
README.md
View File

@@ -214,11 +214,12 @@ Here is some example performance numbers taken from the included
TinyExpr parses the following grammar:
<list> = <expr> {"," <expr>}
<expr> = <term> {("+" | "-") <term>}
<term> = <factor> {("*" | "/" | "%") <factor>}
<factor> = <power> {"^" <power>}
<power> = {("-" | "+")} <base>
<base> = <constant> | <variable> | <function> <power> | "(" <expr> ")"
<base> = <constant> | <variable> | <function-1> <power> | <function-2> "(" <expr> "," <expr> ")" | "(" <list> ")"
In addition, whitespace between tokens is ignored.
@@ -236,7 +237,11 @@ left-to-right).
In addition, the following C math functions are also supported:
- abs (calls to *fabs*), acos, asin, atan, ceil, cos, cosh, exp, floor, ln (calls to *log*), log (calls to *log10*), sin, sinh, sqrt, tan, tanh
- abs (calls to *fabs*), acos, asin, atan, atan2, ceil, cos, cosh, exp, floor, ln (calls to *log*), log (calls to *log10*), pow, sin, sinh, sqrt, tan, tanh
Also, the following constants are available:
- `pi`, `e`
##Hints

29
test.c
View File

@@ -37,6 +37,10 @@ test_case cases[] = {
{"1", 1},
{"(1)", 1},
{"pi", 3.14159},
{"atan(1)*4 - pi", 0},
{"e", 2.71828},
{"2+1", 2+1},
{"(((2+(1))))", 2+1},
{"3+2", 3+2},
@@ -103,6 +107,23 @@ test_case cases[] = {
{"sqrt 100 * 7", 70},
{"sqrt (100 * 100)", 100},
{"1,2", 2},
{"1,2,3", 3},
{"(1,2),3", 3},
{"1,(2,3)", 3},
{"2^2", 4},
{"pow(2,2)", 4},
{"atan2(1,1)", 0.7854},
{"atan2(1,2)", 0.4636},
{"atan2(2,1)", 1.1071},
{"atan2(3,4)", 0.6435},
{"atan2(3+3,4*2)", 0.6435},
{"atan2(3+3,(4*2))", 0.6435},
{"atan2((3+3),4*2)", 0.6435},
{"atan2((3+3),(4*2))", 0.6435},
};
@@ -141,6 +162,10 @@ void test_results() {
const double ev = te_interp(expr, &err);
lok(!err);
lfequal(ev, answer);
if (err) {
printf("FAILED: %s (%d)\n", expr, err);
}
}
}
@@ -160,6 +185,10 @@ void test_syntax() {
lequal(err, e);
lok(!n);
if (err != e) {
printf("FAILED: %s\n", expr);
}
const double k = te_interp(expr, 0);
lok(k != k);
}

125
tinyexpr.c
View File

@@ -29,7 +29,7 @@
#include <stdio.h>
enum {TOK_NULL, TOK_END, TOK_OPEN, TOK_CLOSE, TOK_NUMBER, TOK_ADD, TOK_SUB, TOK_MUL, TOK_DIV, TOK_FUNCTION1, TOK_FUNCTION2, TOK_VARIABLE, TOK_ERROR};
enum {TOK_NULL, TOK_END, TOK_OPEN, TOK_CLOSE, TOK_NUMBER, TOK_INFIX, TOK_FUNCTION1, TOK_FUNCTION2, TOK_VARIABLE, TOK_SEP, TOK_ERROR};
@@ -65,28 +65,36 @@ void te_free(te_expr *n) {
typedef struct {
const char *name;
te_fun1 f1;
union {const void *v; double *value; te_fun1 f1; te_fun2 f2;};
int arity;
} builtin;
static const double pi = 3.14159265358979323846;
static const double e = 2.71828182845904523536;
static const builtin functions[] = {
/* must be in alphabetical order */
{"abs", fabs},
{"acos", acos},
{"asin", asin},
{"atan", atan},
{"ceil", ceil},
{"cos", cos},
{"cosh", cosh},
{"exp", exp},
{"floor", floor},
{"ln", log},
{"log", log10},
{"sin", sin},
{"sinh", sinh},
{"sqrt", sqrt},
{"tan", tan},
{"tanh", tanh},
{"abs", {fabs}, 1},
{"acos", {acos}, 1},
{"asin", {asin}, 1},
{"atan", {atan}, 1},
{"atan2", {atan2}, 2},
{"ceil", {ceil}, 1},
{"cos", {cos}, 1},
{"cosh", {cosh}, 1},
{"e", {&e}, 0},
{"exp", {exp}, 1},
{"floor", {floor}, 1},
{"ln", {log}, 1},
{"log", {log10}, 1},
{"pi", {&pi}, 0},
{"pow", {pow}, 2},
{"sin", {sin}, 1},
{"sinh", {sinh}, 1},
{"sqrt", {sqrt}, 1},
{"tan", {tan}, 1},
{"tanh", {tanh}, 1},
{0}
};
@@ -131,6 +139,7 @@ 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) {return b;}
void next_token(state *s) {
@@ -152,7 +161,7 @@ void next_token(state *s) {
if (s->next[0] >= 'a' && s->next[0] <= 'z') {
const char *start;
start = s->next;
while (s->next[0] >= 'a' && s->next[0] <= 'z') s->next++;
while ((s->next[0] >= 'a' && s->next[0] <= 'z') || (s->next[0] >= '0' && s->next[0] <= '9')) s->next++;
const double *var = find_var(s, start, s->next - start);
if (var) {
@@ -162,12 +171,20 @@ void next_token(state *s) {
if (s->next - start > 15) {
s->type = TOK_ERROR;
} else {
s->type = TOK_FUNCTION1;
const builtin *f = find_function(start, s->next - start);
if (!f) {
s->type = TOK_ERROR;
} else {
if (f->arity == 0) {
s->type = TOK_NUMBER;
s->value = *f->value;
} else if (f->arity == 1) {
s->type = TOK_FUNCTION1;
s->f1 = f->f1;
} else if (f->arity == 2) {
s->type = TOK_FUNCTION2;
s->f2 = f->f2;
}
}
}
}
@@ -175,14 +192,15 @@ void next_token(state *s) {
} else {
/* Look for an operator or special character. */
switch (s->next++[0]) {
case '+': s->type = TOK_FUNCTION2; s->f2 = add; break;
case '-': s->type = TOK_FUNCTION2; s->f2 = sub; break;
case '*': s->type = TOK_FUNCTION2; s->f2 = mul; break;
case '/': s->type = TOK_FUNCTION2; s->f2 = divide; break;
case '^': s->type = TOK_FUNCTION2; s->f2 = pow; break;
case '%': s->type = TOK_FUNCTION2; s->f2 = fmod; break;
case '+': s->type = TOK_INFIX; s->f2 = add; break;
case '-': s->type = TOK_INFIX; s->f2 = sub; break;
case '*': s->type = TOK_INFIX; s->f2 = mul; break;
case '/': s->type = TOK_INFIX; s->f2 = divide; break;
case '^': s->type = TOK_INFIX; s->f2 = pow; break;
case '%': s->type = TOK_INFIX; s->f2 = 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;
}
@@ -192,11 +210,12 @@ void next_token(state *s) {
}
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> <power> | "(" <expr> ")" */
/* <base> = <constant> | <variable> | <function-1> <power> | <function-2> "(" <expr> "," <expr> ")" | "(" <list> ")" */
te_expr *ret;
switch (s->type) {
@@ -219,9 +238,35 @@ static te_expr *base(state *s) {
ret->left = power(s);
break;
case TOK_FUNCTION2:
ret = new_expr(0, 0);
ret->f2 = s->f2;
next_token(s);
if (s->type != TOK_OPEN) {
s->type = TOK_ERROR;
} else {
next_token(s);
ret->left = expr(s);
if (s->type != TOK_SEP) {
s->type = TOK_ERROR;
} else {
next_token(s);
ret->right = expr(s);
if (s->type != TOK_CLOSE) {
s->type = TOK_ERROR;
} else {
next_token(s);
}
}
}
break;
case TOK_OPEN:
next_token(s);
ret = expr(s);
ret = list(s);
if (s->type != TOK_CLOSE) {
s->type = TOK_ERROR;
} else {
@@ -243,7 +288,7 @@ static te_expr *base(state *s) {
static te_expr *power(state *s) {
/* <power> = {("-" | "+")} <base> */
int sign = 1;
while (s->type == TOK_FUNCTION2 && (s->f2 == add || s->f2 == sub)) {
while (s->type == TOK_INFIX && (s->f2 == add || s->f2 == sub)) {
if (s->f2 == sub) sign = -sign;
next_token(s);
}
@@ -265,7 +310,7 @@ static te_expr *factor(state *s) {
/* <factor> = <power> {"^" <power>} */
te_expr *ret = power(s);
while (s->type == TOK_FUNCTION2 && (s->f2 == pow)) {
while (s->type == TOK_INFIX && (s->f2 == pow)) {
te_fun2 t = s->f2;
next_token(s);
ret = new_expr(ret, power(s));
@@ -280,7 +325,7 @@ static te_expr *term(state *s) {
/* <term> = <factor> {("*" | "/" | "%") <factor>} */
te_expr *ret = factor(s);
while (s->type == TOK_FUNCTION2 && (s->f2 == mul || s->f2 == divide || s->f2 == fmod)) {
while (s->type == TOK_INFIX && (s->f2 == mul || s->f2 == divide || s->f2 == fmod)) {
te_fun2 t = s->f2;
next_token(s);
ret = new_expr(ret, factor(s));
@@ -295,7 +340,7 @@ static te_expr *expr(state *s) {
/* <expr> = <term> {("+" | "-") <term>} */
te_expr *ret = term(s);
while (s->type == TOK_FUNCTION2 && (s->f2 == add || s->f2 == sub)) {
while (s->type == TOK_INFIX && (s->f2 == add || s->f2 == sub)) {
te_fun2 t = s->f2;
next_token(s);
ret = new_expr(ret, term(s));
@@ -306,6 +351,20 @@ static te_expr *expr(state *s) {
}
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(ret, term(s));
ret->f2 = comma;
}
return ret;
}
double te_eval(const te_expr *n) {
double ret;
@@ -356,7 +415,7 @@ te_expr *te_compile(const char *expression, const te_variable *variables, int va
s.lookup_len = var_count;
next_token(&s);
te_expr *root = expr(&s);
te_expr *root = list(&s);
if (s.type != TOK_END) {
te_free(root);