Large commit:

- Moved stc/algo/cspan.h to stc/cspan.h - its a data view type similar to csview. +Many updates. Added docs/cspan_api.md page!
- Update c11/fmt.h to VER 2.0: NEW API, see test. NOTE: fmt.h is not officially part of STC, as it is C11, and STC is C99.
- Renamed crange_LITERAL() back to crange_literal(), and cspan_LITERAL() to cspan_literal(). These returns a compound literal (lvalue) that can be passed to a c_FOR*-iterator.

3 files changed, 60 insertions, 33 deletions

diff --git a/include/stc/algo/crange.h b/include/stc/algo/crange.h
index 518320b5..63242a54 100644
--- a/include/stc/algo/crange.h
+++ b/include/stc/algo/crange.h
@@ -34,7 +34,7 @@ int main()
 
     // use a temporary crange object.
     int a = 100, b = INT32_MAX;
-    c_FORFILTER (i, crange, crange_object(a, b, 8)
+    c_FORFILTER (i, crange, crange_literal(a, b, 8)
                   , i.index > 10
                   , c_FLT_TAKE(i, 3))
         printf(" %lld", *i.ref);
@@ -46,7 +46,7 @@ int main()
 
 #include <stc/ccommon.h>
 
-#define crange_object(...) \
+#define crange_literal(...) \
     (*(crange[]){crange_make(__VA_ARGS__)})
 
 typedef long long crange_value;
diff --git a/include/stc/ccommon.h b/include/stc/ccommon.h
index a2c529a7..edf4b2cb 100644
--- a/include/stc/ccommon.h
+++ b/include/stc/ccommon.h
@@ -38,6 +38,11 @@
   #define c_ZU PRIu64
   #define c_NPOS INT64_MAX
 #endif
+#if defined STC_NDEBUG || defined NDEBUG
+  #define c_ASSERT(expr) (void)(expr)
+#else
+  #define c_ASSERT(expr) assert(expr)
+#endif
 
 #if defined(_MSC_VER)
   #pragma warning(disable: 4116 4996) // unnamed type definition in parentheses
diff --git a/include/stc/algo/cspan.h b/include/stc/cspan.h
index 03cb8622..f5114a11 100644
--- a/include/stc/algo/cspan.h
+++ b/include/stc/cspan.h
@@ -22,19 +22,21 @@
  */
 /*
 #include <stdio.h>
-#include <stc/algo/cspan.h>
-
-using_cspan(Span3f, float, 3);
+#include <stc/cspan.h>
+#include <stc/algo/filter.h>
+using_cspan(Span2f, float, 2);
+using_cspan(Intspan, int, 1);
 
 int demo1() {
-    float raw[3*4*5];
-    Span3f span = cspan_make(raw, 3, 4, 5);
-    *cspan_at(&span, 2, 3, 4) = 100;
+    float raw[4*5];
+    Span2f ms = cspan_make(raw, 4, 5);
     
-    printf("%f\n", *cspan_at(&span, 2, 3, 4));
-}
+    for (size_t i=0; i<ms.dim[0]; i++)
+        for (size_t j=0; j<ms.dim[1]; j++)
+            *cspan_at(&ms, i, j) = i*1000 + j;
 
-using_cspan(Intspan, int, 1);
+    printf("%f\n", *cspan_at(&span, 3, 4));
+}
 
 int demo2() {
     int array[] = {1, 2, 3, 4, 5};
@@ -44,8 +46,8 @@ int demo2() {
         printf(" %d", *i.ref);
     puts("");
     
-    // use a temporary IntSpan object.
-    c_FORFILTER (i, Intspan, cspan_object(Intspan, {10, 20, 30, 23, 22, 21})
+    // use a temporary Intspan object.
+    c_FORFILTER (i, Intspan, cspan_literal(Intspan, {10, 20, 30, 23, 22, 21})
                   , c_FLT_SKIPWHILE(i, *i.ref < 25)
                  && (*i.ref & 1) == 0 // even only
                   , c_FLT_TAKE(i, 2)) // break after 2
@@ -56,12 +58,12 @@ int demo2() {
 #ifndef STC_CSPAN_H_INCLUDED
 #define STC_CSPAN_H_INCLUDED
 
-#include "../ccommon.h"
+#include "ccommon.h"
 
 #define using_cspan(Self, T, RANK) \
     typedef T Self##_value, Self##_raw; \
-    typedef struct { Self##_value *data; uint32_t dim[RANK]; } Self; \
     typedef struct { Self##_value *ref, *end; } Self##_iter; \
+    typedef struct { Self##_value *data; uint32_t dim[RANK]; } Self; \
     \
     STC_INLINE Self##_iter Self##_begin(const Self* self) { \
         Self##_iter it = {self->data, self->data + cspan_size(self)}; \
@@ -75,26 +77,46 @@ int demo2() {
         { if (++it->ref == it->end) it->ref = NULL; } \
     struct stc_nostruct
 
-#define cspan_assert(self, rank) c_STATIC_ASSERT(cspan_rank(self) == rank)
+#define using_cspan2(Self, T) using_cspan(Self##1, T, 1); using_cspan(Self##2, T, 2)
+#define using_cspan3(Self, T) using_cspan2(Self, T); using_cspan(Self##3, T, 3)
+#define using_cspan4(Self, T) using_cspan3(Self, T); using_cspan(Self##4, T, 4)
+
+#define cspan_check_rank(self, rank) c_STATIC_ASSERT(cspan_rank(self) == rank)
 
-#define cspan_object(S, ...) \
+#define cspan_literal(S, ...) \
     ((S){.data = (S##_value[])__VA_ARGS__, \
          .dim = {sizeof((S##_value[])__VA_ARGS__)/sizeof(S##_value)}})
 
-#define cspan_make(data, ...) {data, {__VA_ARGS__}}
-#define cspan_from(data) \
-    {data + c_STATIC_ASSERT(sizeof(data) != sizeof(void*)), {c_ARRAYLEN(data)}}
+#define cspan_make(data, ...) \
+    {data, {__VA_ARGS__}}
+
+/* create a cspan from a cvec, cstack, cdeq, cqueue, or cpque (heap) */
+#define cspan_from(container) \
+    {(container)->data, {(container)->_len}}
+
+#define cspan_from_array(array) \
+    {(array) + c_STATIC_ASSERT(sizeof(array) != sizeof(void*)), {c_ARRAYLEN(array)}}
 
 #define cspan_size(self) _cspan_size((self)->dim, cspan_rank(self))
 #define cspan_rank(self) c_ARRAYLEN((self)->dim)
+#define cspan_index(self, ...) \
+    c_PASTE(_cspan_i, c_NUMARGS(__VA_ARGS__))((self)->dim, __VA_ARGS__) + \
+    cspan_check_rank(self, c_NUMARGS(__VA_ARGS__))
 
 #define cspan_reshape(self, ...) \
-    memcpy((self)->dim, (uint32_t[]){__VA_ARGS__}, \
-            sizeof((self)->dim) + cspan_assert(self, c_NUMARGS(__VA_ARGS__)))
+    (void)memcpy((self)->dim, (uint32_t[]){__VA_ARGS__}, \
+                 sizeof((self)->dim) + cspan_check_rank(self, c_NUMARGS(__VA_ARGS__)))
+
+#define cspan_at(self, ...) ((self)->data + cspan_index(self, __VA_ARGS__))
 
-#define cspan_at(self, ...) \
-    ((self)->data + c_PASTE(_cspan_i, c_NUMARGS(__VA_ARGS__))((self)->dim, __VA_ARGS__) \
-                  + cspan_assert(self, c_NUMARGS(__VA_ARGS__)))
+#define cspan_slice4(self, x0, width) \
+    {cspan_at(self, x0, 0, 0, 0), {width, (self)->dim[1], (self)->dim[2], (self)->dim[3]}}
+#define cspan_slice3(self, x0, width) \
+    {cspan_at(self, x0, 0, 0), {width, (self)->dim[1], (self)->dim[2]}}
+#define cspan_slice2(self, x0, width) \
+    {cspan_at(self, x0, 0), {width, (self)->dim[1]}}
+#define cspan_slice1(self, x0, width) \
+    {cspan_at(self, x0), {width}}
 
 #define cspan_4to3(self, x) \
     {cspan_at(self, x, 0, 0, 0), {(self)->dim[1], (self)->dim[2], (self)->dim[3]}}
@@ -109,18 +131,18 @@ int demo2() {
 #define cspan_2to1(self, x) \
     {cspan_at(self, x, 0), {(self)->dim[1]}}
 
-STC_INLINE uint32_t _cspan_i1(const uint32_t dim[1], uint32_t x)
-    { assert(x < dim[0]); return x; }
+STC_INLINE size_t _cspan_i1(const uint32_t dim[1], uint32_t x)
+    { c_ASSERT(x < dim[0]); return x; }
 
-STC_INLINE uint32_t _cspan_i2(const uint32_t dim[2], uint32_t x, uint32_t y)
-    { assert(x < dim[0] && y < dim[1]); return dim[1]*x + y; }
+STC_INLINE size_t _cspan_i2(const uint32_t dim[2], uint32_t x, uint32_t y)
+    { c_ASSERT(x < dim[0] && y < dim[1]); return dim[1]*x + y; }
 
-STC_INLINE uint32_t _cspan_i3(const uint32_t dim[3], uint32_t x, uint32_t y, uint32_t z) {
-    assert(x < dim[0] && y < dim[1] && z < dim[2]);
+STC_INLINE size_t _cspan_i3(const uint32_t dim[3], uint32_t x, uint32_t y, uint32_t z) {
+    c_ASSERT(x < dim[0] && y < dim[1] && z < dim[2]);
     return dim[2]*(dim[1]*x + y) + z;
 }
-STC_INLINE uint32_t _cspan_i4(const uint32_t dim[4], uint32_t x, uint32_t y, uint32_t z, uint32_t w) {
-    assert(x < dim[0] && y < dim[1] && z < dim[3] && w < dim[3]);
+STC_INLINE size_t _cspan_i4(const uint32_t dim[4], uint32_t x, uint32_t y, uint32_t z, uint32_t w) {
+    c_ASSERT(x < dim[0] && y < dim[1] && z < dim[3] && w < dim[3]);
     return dim[3]*(dim[2]*(dim[1]*x + y) + z) + w;
 }
 STC_INLINE size_t _cspan_size(const uint32_t dim[], unsigned rank) {