a little bit code cleanup

diff --git a/kexpr.c b/kexpr.c
index e7ef177bd57d9079ef519e26ac9e843e097d5717..a2e3b6583938111a93cb16437e7f7cbd31959f62 100644 (file)
--- a/kexpr.c
+++ b/kexpr.c
@@ -52,10 +52,7 @@ typedef struct ke1_s {
        uint32_t ttype:16, vtype:16;
        int32_t op:8, n_args:24;
        char *name;
-       union {
-               void (*of)(struct ke1_s *a, struct ke1_s *b);
-               double (*ff1)(double); // not used for now
-       } f;
+       void (*func)(struct ke1_s *a, struct ke1_s *b);
        double r;
        int64_t i;
        char *s;
@@ -63,18 +60,18 @@ typedef struct ke1_s {
 
 static int ke_op[25] = {
        0,
-       1<<1|1, 1<<1|1, 1<<1|1, 1<<1|1,
-       2<<1|1,
-       3<<1, 3<<1, 3<<1, 3<<1,
-       4<<1, 4<<1,
-       5<<1, 5<<1,
-       6<<1, 6<<1, 6<<1, 6<<1,
-       7<<1, 7<<1,
-       8<<1,
-       9<<1,
-       10<<1,
-       11<<1,
-       12<<1
+       1<<1|1, 1<<1|1, 1<<1|1, 1<<1|1, // unary operators
+       2<<1|1, // pow()
+       3<<1, 3<<1, 3<<1, 3<<1, // * / // %
+       4<<1, 4<<1, // + and -
+       5<<1, 5<<1, // << and >>
+       6<<1, 6<<1, 6<<1, 6<<1, // < > <= >=
+       7<<1, 7<<1, // == !=
+       8<<1, // &
+       9<<1, // ^
+       10<<1,// |
+       11<<1,// &&
+       12<<1 // ||
 };
 
 static char *ke_opstr[] = {
@@ -164,11 +161,13 @@ KE_GEN_FUNC1(exp2)
 KE_GEN_FUNC1(sqrt)
 
 static void ke_func1_abs(ke1_t *p, ke1_t *q) { if (p->vtype == KEV_INT) p->i = abs(p->i), p->r = (double)p->i; else p->r = fabs(p->r), p->i = (int64_t)(p->r + .5); }
+static void ke_func1_pow(ke1_t *p, ke1_t *q) { ke_op_KEO_POW(p, q); }
 
 /**********
  * Parser *
  **********/
 
+// parse a token except "(", ")" and ","
 static ke1_t ke_read_token(char *p, char **r, int *err, int last_is_val) // it doesn't parse parentheses
 {
        char *q = p;
@@ -187,14 +186,14 @@ static ke1_t ke_read_token(char *p, char **r, int *err, int last_is_val) // it d
                char *pp;
                e.ttype = KET_VAL;
                y = strtod(q, &p);
-               x = strtol(q, &pp, 0);
-               if (p > pp) {
+               x = strtol(q, &pp, 0); // FIXME: check int/double parsing errors
+               if (p > pp) { // has "." or "[eE]"; then it is a real number
                        e.vtype = KEV_REAL;
                        e.i = (int64_t)(y + .5), e.r = y;
                        *r = p;
                } else {
                        e.vtype = KEV_INT;
-                       e.i = x, e.r = x;
+                       e.i = x, e.r = y;
                        *r = pp;
                }
        } else if (*p == '"' || *p == '\'') { // a string value
@@ -202,42 +201,41 @@ static ke1_t ke_read_token(char *p, char **r, int *err, int last_is_val) // it d
                for (++p; *p && *p != c; ++p)
                        if (*p == '\\') ++p; // escaping
                if (*p == c) {
-                       e.ttype = KET_VAL;
-                       e.vtype = KEV_STR;
+                       e.ttype = KET_VAL, e.vtype = KEV_STR;
                        e.s = strndup(q + 1, p - q - 1);
                        *r = p + 1;
-               } else *err |= KEE_UNDQ, *r = p;
-       } else {
+               } else *err |= KEE_UNQU, *r = p;
+       } else { // an operator
                e.ttype = KET_OP;
-               if (*p == '*' && p[1] == '*') e.op = KEO_POW, e.f.of = ke_op_KEO_POW, e.n_args = 2, *r = q + 2;
-               else if (*p == '*') e.op = KEO_MUL, e.f.of = ke_op_KEO_MUL, e.n_args = 2, *r = q + 1; // FIXME: NOT working for unary operators
-               else if (*p == '/' && p[1] == '/') e.op = KEO_IDIV, e.f.of = ke_op_KEO_IDIV, e.n_args = 2, *r = q + 2;
-               else if (*p == '/') e.op = KEO_DIV, e.f.of = ke_op_KEO_DIV, e.n_args = 2, *r = q + 1;
-               else if (*p == '%') e.op = KEO_MOD, e.f.of = ke_op_KEO_MOD, e.n_args = 2, *r = q + 1;
+               if (*p == '*' && p[1] == '*') e.op = KEO_POW, e.func = ke_op_KEO_POW, e.n_args = 2, *r = q + 2;
+               else if (*p == '*') e.op = KEO_MUL, e.func = ke_op_KEO_MUL, e.n_args = 2, *r = q + 1; // FIXME: NOT working for unary operators
+               else if (*p == '/' && p[1] == '/') e.op = KEO_IDIV, e.func = ke_op_KEO_IDIV, e.n_args = 2, *r = q + 2;
+               else if (*p == '/') e.op = KEO_DIV, e.func = ke_op_KEO_DIV, e.n_args = 2, *r = q + 1;
+               else if (*p == '%') e.op = KEO_MOD, e.func = ke_op_KEO_MOD, e.n_args = 2, *r = q + 1;
                else if (*p == '+') {
-                       if (last_is_val) e.op = KEO_ADD, e.f.of = ke_op_KEO_ADD, e.n_args = 2;
-                       else e.op = KEO_POS, e.f.of = ke_op_KEO_POS, e.n_args = 1;
+                       if (last_is_val) e.op = KEO_ADD, e.func = ke_op_KEO_ADD, e.n_args = 2;
+                       else e.op = KEO_POS, e.func = ke_op_KEO_POS, e.n_args = 1;
                        *r = q + 1;
                } else if (*p == '-') {
-                       if (last_is_val) e.op = KEO_SUB, e.f.of = ke_op_KEO_SUB, e.n_args = 2;
-                       else e.op = KEO_NEG, e.f.of = ke_op_KEO_NEG, e.n_args = 1;
+                       if (last_is_val) e.op = KEO_SUB, e.func = ke_op_KEO_SUB, e.n_args = 2;
+                       else e.op = KEO_NEG, e.func = ke_op_KEO_NEG, e.n_args = 1;
                        *r = q + 1;
-               } else if (*p == '=' && p[1] == '=')e.op = KEO_EQ,e.f.of = ke_op_KEO_EQ, e.n_args = 2, *r = q + 2;
-               else if (*p == '!' && p[1] == '=') e.op = KEO_NE, e.f.of = ke_op_KEO_NE, e.n_args = 2, *r = q + 2;
-               else if (*p == '>' && p[1] == '=') e.op = KEO_GE, e.f.of = ke_op_KEO_GE, e.n_args = 2, *r = q + 2;
-               else if (*p == '<' && p[1] == '=') e.op = KEO_LE, e.f.of = ke_op_KEO_LE, e.n_args = 2, *r = q + 2;
-               else if (*p == '>' && p[1] == '>') e.op = KEO_RSH, e.f.of = ke_op_KEO_RSH, e.n_args = 2, *r = q + 2;
-               else if (*p == '<' && p[1] == '<') e.op = KEO_LSH, e.f.of = ke_op_KEO_LSH, e.n_args = 2, *r = q + 2;
-               else if (*p == '>') e.op = KEO_GT, e.f.of = ke_op_KEO_GT, e.n_args = 2, *r = q + 1;
-               else if (*p == '<') e.op = KEO_LT, e.f.of = ke_op_KEO_LT, e.n_args = 2, *r = q + 1;
-               else if (*p == '|' && p[1] == '|') e.op = KEO_LOR, e.f.of = ke_op_KEO_LOR, e.n_args = 2, *r = q + 2;
-               else if (*p == '&' && p[1] == '&') e.op = KEO_LAND, e.f.of = ke_op_KEO_LAND, e.n_args = 2, *r = q + 2;
-               else if (*p == '|') e.op = KEO_BOR, e.f.of = ke_op_KEO_BOR, e.n_args = 2, *r = q + 1;
-               else if (*p == '&') e.op = KEO_BAND, e.f.of = ke_op_KEO_BAND, e.n_args = 2, *r = q + 1;
-               else if (*p == '^') e.op = KEO_BXOR, e.f.of = ke_op_KEO_BXOR, e.n_args = 2, *r = q + 1;
-               else if (*p == '~') e.op = KEO_BNOT, e.f.of = ke_op_KEO_BNOT, e.n_args = 1, *r = q + 1;
-               else if (*p == '!') e.op = KEO_LNOT, e.f.of = ke_op_KEO_LNOT, e.n_args = 1, *r = q + 1;
-               else e.ttype = KET_NULL, *err |= KEE_UNTO;
+               } else if (*p == '=' && p[1] == '=')e.op = KEO_EQ,e.func = ke_op_KEO_EQ, e.n_args = 2, *r = q + 2;
+               else if (*p == '!' && p[1] == '=') e.op = KEO_NE, e.func = ke_op_KEO_NE, e.n_args = 2, *r = q + 2;
+               else if (*p == '>' && p[1] == '=') e.op = KEO_GE, e.func = ke_op_KEO_GE, e.n_args = 2, *r = q + 2;
+               else if (*p == '<' && p[1] == '=') e.op = KEO_LE, e.func = ke_op_KEO_LE, e.n_args = 2, *r = q + 2;
+               else if (*p == '>' && p[1] == '>') e.op = KEO_RSH, e.func = ke_op_KEO_RSH, e.n_args = 2, *r = q + 2;
+               else if (*p == '<' && p[1] == '<') e.op = KEO_LSH, e.func = ke_op_KEO_LSH, e.n_args = 2, *r = q + 2;
+               else if (*p == '>') e.op = KEO_GT, e.func = ke_op_KEO_GT, e.n_args = 2, *r = q + 1;
+               else if (*p == '<') e.op = KEO_LT, e.func = ke_op_KEO_LT, e.n_args = 2, *r = q + 1;
+               else if (*p == '|' && p[1] == '|') e.op = KEO_LOR, e.func = ke_op_KEO_LOR, e.n_args = 2, *r = q + 2;
+               else if (*p == '&' && p[1] == '&') e.op = KEO_LAND, e.func = ke_op_KEO_LAND, e.n_args = 2, *r = q + 2;
+               else if (*p == '|') e.op = KEO_BOR, e.func = ke_op_KEO_BOR, e.n_args = 2, *r = q + 1;
+               else if (*p == '&') e.op = KEO_BAND, e.func = ke_op_KEO_BAND, e.n_args = 2, *r = q + 1;
+               else if (*p == '^') e.op = KEO_BXOR, e.func = ke_op_KEO_BXOR, e.n_args = 2, *r = q + 1;
+               else if (*p == '~') e.op = KEO_BNOT, e.func = ke_op_KEO_BNOT, e.n_args = 1, *r = q + 1;
+               else if (*p == '!') e.op = KEO_LNOT, e.func = ke_op_KEO_LNOT, e.n_args = 1, *r = q + 1;
+               else e.ttype = KET_NULL, *err |= KEE_UNOP;
        }
        return e;
 }
@@ -270,29 +268,32 @@ static ke1_t *ke_parse_core(const char *_s, int *_n, int *err)
        p = s;
        while (*p) {
                if (*p == '(') {
-                       t = push_back(&op, &n_op, &m_op);
-                       t->op = -1, t->ttype = KET_NULL;
+                       t = push_back(&op, &n_op, &m_op); // push to the operator stack
+                       t->op = -1, t->ttype = KET_NULL; // ->op < 0 for a left parenthsis
                        ++p;
                } else if (*p == ')') {
-                       while (n_op > 0 && op[n_op-1].op >= 0) {
+                       while (n_op > 0 && op[n_op-1].op >= 0) { // move operators to the output until we see a left parenthesis
                                u = push_back(&out, &n_out, &m_out);
                                *u = op[--n_op];
                        }
-                       if (n_op < 0) {
+                       if (n_op < 0) { // error: extra right parenthesis
                                *err |= KEE_UNRP;
                                break;
                        } else --n_op; // pop out '('
-                       if (n_op > 0 && op[n_op-1].ttype == KET_FUNC) {
-                               u = push_back(&out, &n_out, &m_out); // pop out function and push to the output
+                       if (n_op > 0 && op[n_op-1].ttype == KET_FUNC) { // the top of the operator stack is a function
+                               u = push_back(&out, &n_out, &m_out); // move it to the output
                                *u = op[--n_op];
                                if (u->n_args == 1) {
-                                       if (strcmp(u->name, "abs") == 0) u->f.of = ke_func1_abs;
-                                       else if (strcmp(u->name, "log") == 0) u->f.of = ke_func1_log;
-                                       else if (strcmp(u->name, "exp") == 0) u->f.of = ke_func1_exp;
-                                       else if (strcmp(u->name, "log2") == 0) u->f.of = ke_func1_log2;
-                                       else if (strcmp(u->name, "exp2") == 0) u->f.of = ke_func1_exp2;
-                                       else if (strcmp(u->name, "log10") == 0) u->f.of = ke_func1_log10;
-                                       else if (strcmp(u->name, "sqrt") == 0) u->f.of = ke_func1_sqrt;
+                                       if (strcmp(u->name, "abs") == 0) u->func = ke_func1_abs;
+                                       else if (strcmp(u->name, "log") == 0) u->func = ke_func1_log;
+                                       else if (strcmp(u->name, "exp") == 0) u->func = ke_func1_exp;
+                                       else if (strcmp(u->name, "log2") == 0) u->func = ke_func1_log2;
+                                       else if (strcmp(u->name, "exp2") == 0) u->func = ke_func1_exp2;
+                                       else if (strcmp(u->name, "log10") == 0) u->func = ke_func1_log10;
+                                       else if (strcmp(u->name, "sqrt") == 0) u->func = ke_func1_sqrt;
+                                       else { *err |= KEE_UNFUNC; break; }
+                               } else if (u->n_args == 2) {
+                                       if (strcmp(u->name, "pow") == 0) u->func = ke_func1_pow; // for now, this to test functions with multiple arguments
                                        else { *err |= KEE_UNFUNC; break; }
                                } else {
                                        *err |= KEE_UNFUNC;
@@ -300,12 +301,12 @@ static ke1_t *ke_parse_core(const char *_s, int *_n, int *err)
                                }
                        }
                        ++p;
-               } else if (*p == ',') {
+               } else if (*p == ',') { // function arguments separator
                        while (n_op > 0 && op[n_op-1].op >= 0) {
                                u = push_back(&out, &n_out, &m_out);
                                *u = op[--n_op];
                        }
-                       if (n_op < 2 || op[n_op-2].ttype != KET_FUNC) {
+                       if (n_op < 2 || op[n_op-2].ttype != KET_FUNC) { // we should at least see a function and a left parenthesis
                                *err |= KEE_FUNC;
                                break;
                        }
@@ -368,37 +369,33 @@ static ke1_t *ke_parse_core(const char *_s, int *_n, int *err)
 kexpr_t *ke_parse(const char *_s, int *err)
 {
        int n;
-       ke1_t *a;
+       ke1_t *e;
        kexpr_t *ke;
-       a = ke_parse_core(_s, &n, err);
+       e = ke_parse_core(_s, &n, err);
        if (*err) return 0;
        ke = (kexpr_t*)calloc(1, sizeof(kexpr_t));
-       ke->n = n;
-       ke->e = a;
+       ke->n = n, ke->e = e;
        return ke;
 }
 
-int ke_eval(const kexpr_t *ke, int64_t *_i, double *_r, int *int_ret)
+void ke_eval(const kexpr_t *ke, int64_t *_i, double *_r, int *int_ret)
 {
        ke1_t *stack, *p, *q;
-       int i, top = 0, err = 0;
+       int i, top = 0;
        stack = (ke1_t*)malloc(ke->n * sizeof(ke1_t));
        for (i = 0; i < ke->n; ++i) {
                ke1_t *e = &ke->e[i];
-               if (e->ttype == KET_VAL) {
-                       stack[top++] = *e;
-               } else if (e->ttype == KET_OP || e->ttype == KET_FUNC) {
+               if (e->ttype == KET_OP || e->ttype == KET_FUNC) {
                        if (e->n_args == 2) {
                                q = &stack[--top], p = &stack[top-1];
-                               e->f.of(p, q);
+                               e->func(p, q);
                        } else if (e->n_args == 1) {
-                               e->f.of(&stack[top-1], 0);
-                       }
-               }
+                               e->func(&stack[top-1], 0);
+                       } else abort(); // TODO: so far, no functions have three or more arguments; may happen in future
+               } else stack[top++] = *e;
        }
        free(stack);
        *_i = stack->i, *_r = stack->r, *int_ret = (stack->vtype == KEV_INT);
-       return err;
 }
 
 void ke_destroy(kexpr_t *ke)
@@ -507,11 +504,7 @@ int main(int argc, char *argv[])
                                ke_set_real(ke, s, strtod(p+1, &p));
                        }
                }
-               err = ke_eval(ke, &vi, &vr, &int_ret);
-               if (err) {
-                       fprintf(stderr, "ERROR: 0x%x\n", err);
-                       return 1;
-               }
+               ke_eval(ke, &vi, &vr, &int_ret);
                if (is_int) printf("%lld\n", (long long)vi);
                else printf("%g\n", vr);
        } else ke_print(ke);

diff --git a/kexpr.h b/kexpr.h
index c91319d1c0abd25984d81ae348d67519ad02297b..1e49b5c53b8fb67935162d90657bca5601d6382f 100644 (file)
--- a/kexpr.h
+++ b/kexpr.h
@@ -6,13 +6,13 @@
 struct kexpr_s;
 typedef struct kexpr_s kexpr_t;
 
-#define KEE_UNDQ    0x01 // unmatched double quotation marks
+#define KEE_UNQU    0x01 // unmatched quotation marks
 #define KEE_UNLP    0x02 // unmatched left parentheses
 #define KEE_UNRP    0x04 // unmatched right parentheses
-#define KEE_UNTO    0x08 // unknown tokens
+#define KEE_UNOP    0x08 // unknown operators
 #define KEE_FUNC    0x10 // wrong function
-#define KEE_ARG     0x20
-#define KEE_UNFUNC  0x40 // undefined function
+#define KEE_UNFUNC  0x20 // undefined function
+#define KEE_ARG     0x40
 
 #ifdef __cplusplus
 extern "C" {
@@ -24,7 +24,7 @@ void ke_print(const kexpr_t *ke);
 int ke_set_int(kexpr_t *ke, const char *var, int64_t x);
 int ke_set_real(kexpr_t *ke, const char *var, double x);
 int ke_set_str(kexpr_t *ke, const char *var, const char *x);
-int ke_eval(const kexpr_t *ke, int64_t *_i, double *_r, int *int_ret);
+void ke_eval(const kexpr_t *ke, int64_t *_i, double *_r, int *int_ret);
 
 #ifdef __cplusplus
 }