Safer state machine in coroutine.h (internal).

Removed c_forwhile() macro. Redundant, use c_forfilter().
Removed find and eq in cspan (use general c_find_if() instead for search).

13 files changed, 66 insertions, 80 deletions

diff --git a/README.md b/README.md
index f74ee916..c214413b 100644
--- a/README.md
+++ b/README.md
@@ -547,7 +547,6 @@ STC is generally very memory efficient. Type sizes:
 ## API changes summary V4.0
 - Added **cregex** with documentation - powerful regular expressions.
 - Added: `c_forfilter`: container iteration with "piped" filtering using && operator. 4 built-in filters.
-- Added: `c_forwhile`: *c_foreach* container iteration with extra predicate.
 - Added: **crange**: number generator type, which can be iterated (e.g. with *c_forfilter*).
 - Added back **coption** - command line argument parsing.
 - New + renamed loop iteration/scope macros:
diff --git a/docs/ccommon_api.md b/docs/ccommon_api.md
index 8dcb2ff3..ff75d83d 100644
--- a/docs/ccommon_api.md
+++ b/docs/ccommon_api.md
@@ -176,7 +176,7 @@ Iterate containers with stop-criteria and chained range filtering.
 | Usage                                               | Description                            |
 |:----------------------------------------------------|:---------------------------------------|
 | `c_forfilter (it, ctype, container, filter)`        | Filter out items in chain with &&      |
-| `c_forwhile (it, ctype, start, pred)`               | Iterate until pred is false            |
+| `c_forfilter_it (it, ctype, startit, filter)`       | Filter from startit position           |
 
 | Built-in filter                   | Description                          |
 |:----------------------------------|:-------------------------------------|
@@ -203,10 +203,10 @@ int main() {
     crange R = crange_make(1001, INT32_MAX, 2);
 
     c_forfilter (i, crange, R,
-                    isPrime(*i.ref)
-                 && c_flt_skip(i, 24)
-                 && c_flt_count(i) % 15 == 1
-                 && c_flt_take(i, 10))
+                    isPrime(*i.ref)          &&
+                    c_flt_skip(i, 24)        &&
+                    c_flt_count(i) % 15 == 1 &&
+                    c_flt_take(i, 10))
         printf(" %lld", *i.ref);
     puts("");
 }
@@ -237,9 +237,9 @@ c_forfilter (i, crange, r1, isPrime(*i.ref))
 
 // 2. The 11 first primes:
 printf("2");
-c_forfilter (i, crange, crange_obj(3, INT64_MAX, 2)
-              , isPrime(*i.ref)
-             && c_flt_take(10))
+c_forfilter (i, crange, crange_obj(3, INT64_MAX, 2),
+                isPrime(*i.ref) &&
+                c_flt_take(10))
     printf(" %lld", *i.ref);
 // 2 3 5 7 11 13 17 19 23 29 31
 ```
diff --git a/include/stc/algo/coroutine.h b/include/stc/algo/coroutine.h
index 1c849d49..1dd82720 100644
--- a/include/stc/algo/coroutine.h
+++ b/include/stc/algo/coroutine.h
@@ -68,12 +68,11 @@ enum {
 #define cco_begin(ctx) \
     int *_state = &(ctx)->cco_state; \
     switch (*_state) { \
-        case cco_state_done: \
         case 0:
 
 #define cco_end(retval) \
         *_state = cco_state_done; break; \
-        default: goto _cco_final_; /*  never happens */ \
+        default: assert(0); goto _cco_final_; \
     } \
     return retval
 
@@ -109,4 +108,10 @@ enum {
         if (*_state > 0) *_state = cco_state_final; \
     } while (0)
 
+#define cco_reset(ctx) \
+    do { \
+        int* _state = &(ctx)->cco_state; \
+        if (*_state == cco_state_final) *_state = 0; \
+    } while (0)
+
 #endif
diff --git a/include/stc/algo/crange.h b/include/stc/algo/crange.h
index 4fc957b6..ca06c258 100644
--- a/include/stc/algo/crange.h
+++ b/include/stc/algo/crange.h
@@ -34,9 +34,9 @@ int main()
 
     // use a temporary crange object.
     int a = 100, b = INT32_MAX;
-    c_forfilter (i, crange, crange_obj(a, b, 8)
-                  , i.index > 10
-                && c_flt_take(i, 3))
+    c_forfilter (i, crange, crange_obj(a, b, 8),
+                    c_flt_skip(i, 10) &&
+                    c_flt_take(i, 3))
         printf(" %lld", *i.ref);
     puts("");
 }
diff --git a/include/stc/algo/filter.h b/include/stc/algo/filter.h
index a5e11b64..5e3125b1 100644
--- a/include/stc/algo/filter.h
+++ b/include/stc/algo/filter.h
@@ -35,10 +35,10 @@ int main()
             printf(" %d", *i.ref);
         puts("");
         
-        c_forfilter (i, cstack_int, stk
-                      , c_flt_skipwhile(i, *i.ref < 3)
-                     && (*i.ref & 1) == 0 // even only
-                     && c_flt_take(i, 2)) // break after 2
+        c_forfilter (i, cstack_int, stk,
+                        c_flt_skipwhile(i, *i.ref < 3) &&
+                        (*i.ref & 1) == 0              && // even only
+                        c_flt_take(i, 2))                 // break after 2
             printf(" %d", *i.ref);
         puts("");
     }
@@ -57,8 +57,11 @@ int main()
 #define c_flt_last(i) (i).b.s1[(i).b.s1top - 1]
 
 #define c_forfilter(i, C, cnt, filter) \
+    c_forfilter_it(i, C, C##_begin(&cnt), filter)
+
+#define c_forfilter_it(i, C, start, filter) \
     for (struct {struct _flt_base b; C##_iter it; C##_value *ref;} \
-         i = {.it=C##_begin(&cnt), .ref=i.it.ref} ; !i.b.done & (i.it.ref != NULL) ; \
+         i = {.it=start, .ref=i.it.ref} ; !i.b.done & (i.it.ref != NULL) ; \
          C##_next(&i.it), i.ref = i.it.ref, i.b.s1top=0, i.b.s2top=0) \
       if (!(filter)) ; else
 
diff --git a/include/stc/ccommon.h b/include/stc/ccommon.h
index de230910..33446982 100644
--- a/include/stc/ccommon.h
+++ b/include/stc/ccommon.h
@@ -178,11 +178,6 @@ STC_INLINE char* cstrnstrn(const char *str, const char *needle,
     for (C##_iter it = start, *_endref = (C##_iter*)(finish).ref \
          ; it.ref != (C##_value*)_endref; C##_next(&it))
 
-#define c_forwhile(i, C, cnt, cond) \
-    for (struct {C##_iter it; C##_value *ref; intptr_t index;} \
-         i = {.it=C##_begin(&cnt), .ref=i.it.ref}; i.it.ref && (cond) \
-         ; C##_next(&i.it), i.ref = i.it.ref, ++i.index)
-
 #define c_forpair(key, val, C, cnt) /* structured binding */ \
     for (struct {C##_iter it; const C##_key* key; C##_mapped* val;} _ = {.it=C##_begin(&cnt)} \
          ; _.it.ref && (_.key = &_.it.ref->first, _.val = &_.it.ref->second) \
diff --git a/include/stc/cspan.h b/include/stc/cspan.h
index 00313540..d5482200 100644
--- a/include/stc/cspan.h
+++ b/include/stc/cspan.h
@@ -48,9 +48,9 @@ int demo2() {
     puts("");
     
     c_forfilter (i, Intspan, span,
-                  , c_flt_skipwhile(i, *i.ref < 25)
-                 && (*i.ref & 1) == 0 // even only
-                 && c_flt_take(i, 2)) // break after 2
+                    c_flt_skipwhile(i, *i.ref < 25) &&
+                    (*i.ref & 1) == 0               && // even only
+                    c_flt_take(i, 2))                  // break after 2
         printf(" %d", *i.ref);
     puts("");
 }
@@ -65,9 +65,6 @@ int demo2() {
     using_cspan_3(Self, T, 1)
 
 #define using_cspan_3(Self, T, RANK) \
-    using_cspan_4(Self, T, RANK, c_default_eq)
-
-#define using_cspan_4(Self, T, RANK, i_eq) \
     typedef T Self##_value; typedef T Self##_raw; \
     typedef struct { \
         Self##_value *data; \
@@ -99,18 +96,6 @@ int demo2() {
         it->ref += _cspan_next##RANK(RANK, it->pos, it->_s->shape, it->_s->stride.d); \
         if (it->pos[0] == it->_s->shape[0]) it->ref = NULL; \
     } \
-    STC_INLINE bool Self##_eq(const Self* x, const Self* y) { \
-        if (memcmp(x->shape, y->shape, sizeof x->shape)) return false; \
-        Self##_iter i = Self##_begin(x), j = Self##_begin(y); \
-        for (; i.ref; Self##_next(&i), Self##_next(&j)) \
-            if (!(i_eq(i.ref, j.ref))) return false; \
-        return true; \
-    } \
-    STC_INLINE Self##_iter Self##_find(const Self* self, Self##_raw raw) { \
-        Self##_iter i = Self##_begin(self); \
-        for (; i.ref; Self##_next(&i)) if (i_eq(i.ref, &raw)) return i; \
-        return i; \
-    } \
     struct stc_nostruct
 
 #define using_cspan2(Self, T) using_cspan_3(Self, T, 1); using_cspan_3(Self##2, T, 2)
diff --git a/include/stc/priv/altnames.h b/include/stc/priv/altnames.h
index b10c7a11..8fa326f1 100644
--- a/include/stc/priv/altnames.h
+++ b/include/stc/priv/altnames.h
@@ -23,7 +23,6 @@
 #define c_FORLIST c_forlist
 #define c_FORRANGE c_forrange
 #define c_FOREACH c_foreach
-#define c_FORWHILE c_forwhile
 #define c_FORPAIR c_forpair
 #define c_FORFILTER c_forfilter
 #define c_FORMATCH c_formatch
diff --git a/misc/examples/forfilter.c b/misc/examples/forfilter.c
index 2be975a6..cd6d59cc 100644
--- a/misc/examples/forfilter.c
+++ b/misc/examples/forfilter.c
@@ -32,13 +32,13 @@ void demo1(void)
         puts("");
 
         int res, sum = 0;
-        c_forfilter (i, IVec, vec
-                      , c_flt_skipwhile(i, *i.ref != 80)
-                     && c_flt_skip(i, 1)
-                     && c_flt_skipwhile(i, *i.ref != 80)
-                     && flt_isEven(i)
-                     && flt_skipValue(i, 80)
-                     && c_flt_take(i, 5) // short-circuit
+        c_forfilter (i, IVec, vec,
+                        c_flt_skipwhile(i, *i.ref != 80) &&
+                        c_flt_skip(i, 1)                 &&
+                        c_flt_skipwhile(i, *i.ref != 80) &&
+                        flt_isEven(i)                    &&
+                        flt_skipValue(i, 80)             &&
+                        c_flt_take(i, 5) // short-circuit
         ){
             sum += res = flt_square(i);
             printf(" %d", res);
@@ -65,10 +65,10 @@ void demo2(void)
     c_auto (IVec, vector) {
         puts("demo2:");
         crange R = crange_make(INT64_MAX);
-        c_forfilter (x, crange, R
-                      , c_flt_skipwhile(x, *x.ref != 11)
-                     && *x.ref % 2 != 0
-                     && c_flt_take(x, 5))
+        c_forfilter (x, crange, R,
+                        c_flt_skipwhile(x, *x.ref != 11) &&
+                        *x.ref % 2 != 0                  &&
+                        c_flt_take(x, 5))
             IVec_push(&vector, (int)(*x.ref * *x.ref));
         c_foreach (x, IVec, vector)
             printf(" %d", *x.ref);
@@ -97,7 +97,7 @@ void demo3(void)
             SVec_push(&words, *w.ref);
 
         c_forfilter (w, SVec, words, 
-                     csview_contains(*w.ref, "i"))
+                        csview_contains(*w.ref, "i"))
             SVec_push(&words_containing_i, *w.ref);
 
         puts("demo3:");
@@ -127,12 +127,12 @@ void demo5(void)
     #define flt_mid_decade(i) ((*i.ref % 10) != 0)
     puts("demo5:");
     crange R = crange_make(1963, INT32_MAX);
-    c_forfilter (i, crange, R
-                  , c_flt_skip(i,15)
-                 && c_flt_skipwhile(i, flt_mid_decade(i))
-                 && c_flt_skip(i,30)
-                 && flt_even(i)
-                 && c_flt_take(i,5))
+    c_forfilter (i, crange, R,
+                    c_flt_skip(i,15)                      &&
+                    c_flt_skipwhile(i, flt_mid_decade(i)) &&
+                    c_flt_skip(i,30)                      &&
+                    flt_even(i)                           &&
+                    c_flt_take(i,5))
         printf(" %lld", *i.ref);
     puts("");
 }
diff --git a/misc/examples/forloops.c b/misc/examples/forloops.c
index 707e8285..144ec637 100644
--- a/misc/examples/forloops.c
+++ b/misc/examples/forloops.c
@@ -60,20 +60,20 @@ int main()
         c_forpair (key, val, IMap, map)

             printf(" (%d %d)", *_.key, *_.val);

 

-        puts("\n\nc_forwhile:");

-        c_forwhile (i, IVec, IVec_begin(&vec), i.index < 3)

+        puts("\n\nc_forfilter 1:");

+        c_forfilter (i, IVec, vec, c_flt_take(i, 3))

             printf(" %d", *i.ref);

 

         #define isOdd(i) (*i.ref & 1)

 

-        puts("\n\nc_forfilter:");

-        c_forfilter (i, IVec, vec

-                      , c_flt_skipwhile(i, *i.ref != 65)

-                     && c_flt_takewhile(i, *i.ref != 280)

-                     && c_flt_skipwhile(i, isOdd(i))

-                     && isOdd(i)

-                     && c_flt_skip(i, 2)

-                     && c_flt_take(i, 2))

+        puts("\n\nc_forfilter 2:");

+        c_forfilter (i, IVec, vec,

+                        c_flt_skipwhile(i, *i.ref != 65)  &&

+                        c_flt_takewhile(i, *i.ref != 280) &&

+                        c_flt_skipwhile(i, isOdd(i))      &&

+                        isOdd(i)                          &&

+                        c_flt_skip(i, 2)                  &&

+                        c_flt_take(i, 2))

             printf(" %d", *i.ref);

         puts("");

         // 189

diff --git a/misc/examples/list.c b/misc/examples/list.c
index b345bd16..c12d67e9 100644
--- a/misc/examples/list.c
+++ b/misc/examples/list.c
@@ -1,11 +1,12 @@
 #include <stdio.h>
 #include <time.h>
+#include <stc/calgo.h>
+#include <stc/crandom.h>
 
 #define i_val double
 #define i_tag fx
 #define i_extern // include sort function
 #include <stc/clist.h>
-#include <stc/crandom.h>
 
 int main() {
     const int n = 1000000;
@@ -24,8 +25,8 @@ int main() {
             sum += *i.ref;
         printf("sum %f\n\n", sum);
 
-        c_forwhile (i, clist_fx, clist_fx_begin(&list), i.index < 10)
-            printf("%8d: %10f\n", (int)i.index, *i.ref);
+        c_forfilter (i, clist_fx, list, c_flt_take(i, 10))
+            printf("%8d: %10f\n", c_flt_last(i), *i.ref);
 
         puts("sort");
         clist_fx_sort(&list); // mergesort O(n*log n)
@@ -37,8 +38,8 @@ int main() {
             last = *i.ref;
         }
 
-        c_forwhile (i, clist_fx, clist_fx_begin(&list), i.index < 10)
-            printf("%8d: %10f\n", (int)i.index, *i.ref);
+        c_forfilter (i, clist_fx, list, c_flt_take(i, 10))
+            printf("%8d: %10f\n", c_flt_last(i), *i.ref);
         puts("");
 
         clist_fx_clear(&list);
diff --git a/misc/examples/prime.c b/misc/examples/prime.c
index 59ee336c..16a59774 100644
--- a/misc/examples/prime.c
+++ b/misc/examples/prime.c
@@ -43,9 +43,9 @@ int main(void)
 
         puts("Show the last 50 primes using a temporary crange generator:");
         crange R = crange_make(n - 1, 0, -2);
-        c_forfilter (i, crange, R
-                      , cbits_test(&primes, *i.ref>>1)
-                     && c_flt_take(i, 50)) {
+        c_forfilter (i, crange, R,
+                        cbits_test(&primes, *i.ref>>1) &&
+                        c_flt_take(i, 50)) {
             printf("%lld ", *i.ref);
             if (c_flt_last(i) % 10 == 0) puts("");
         }
diff --git a/src/checkauto.l b/src/checkauto.l
index ab71403c..349da70b 100644
--- a/src/checkauto.l
+++ b/src/checkauto.l
@@ -35,7 +35,6 @@ c_foreach       |
 c_forpair       |
 c_forrange      |
 c_forfilter     |
-c_forwhile      |
 c_formatch      |
 c_fortoken      |
 for             |