Reverted cspan_subdim*() to cspan_at*(). Added cspan_flatten() constructor.

3 files changed, 18 insertions, 14 deletions

diff --git a/docs/cspan_api.md b/docs/cspan_api.md
index d6caff4e..ce9236c3 100644
--- a/docs/cspan_api.md
+++ b/docs/cspan_api.md
@@ -25,6 +25,7 @@ SpanTypeN       cspan_make(ValueType* data,  size_t xdim, ...);         // make
 SpanType        cspan_from(STCContainer* cnt);                          // create a 1D cspan from a compatible STC container
 SpanType        cspan_from_array(ValueType array[]);                    // create a 1D cspan from a C array
 
+SpanType        cspan_flatten(SpanTypeN* span);                         // create a 1D cspan from a multidim span
 void            cspan_resize(SpanTypeN* self, size_t xdim, ...);        // change the extent of each dimension
 
 size_t          cspan_size(const SpanTypeN* self);                      // return number of elements
@@ -35,9 +36,9 @@ ValueType*      cspan_at(SpanTypeN* self, size_t x, ...);               // at():
 ValueType*      cspan_front(SpanTypeN* self);
 ValueType*      cspan_back(SpanTypeN* self);
 
-SpanType        cspan_subdim2(SpanType2* self, size_t x);               // return a cspan from a 2D SpanType.
-SpanTypeN       cspan_subdim3(SpanType3* self, size_t x, ...);          // subdimN(): N decides input SpanType,
-SpanTypeN       cspan_subdim4(SpanType4* self, size_t x, ...);          // and num of args decides returned SpanTypeN.
+SpanType        cspan_at2(SpanType2* self, size_t x);               // return a cspan from a 2D SpanType.
+SpanTypeN       cspan_at3(SpanType3* self, size_t x, ...);          // atN(): N decides input SpanType,
+SpanTypeN       cspan_at4(SpanType4* self, size_t x, ...);          // and num of args decides returned SpanTypeN.
 
                 // return a subspan of same rank:
 SpanType        cspan_subspan(const SpanType* self, size_t offset, size_t count);
@@ -79,12 +80,12 @@ int main()
         *cspan_at(&span3, 4, 3, 2) = 3.14159f;
         printf("index: %d", (int)cspan_index(&span3, 4, 3, 2));
 
-        Span span1 = cspan_subdim3(&span3, 4, 3);
+        Span span1 = cspan_at3(&span3, 4, 3);
         printf("\niterate span1: ");
         c_FOREACH (i, Span, span1)
             printf("%g ", *i.ref);
 
-        Span2 span2 = cspan_subdim3(&span3, 4);
+        Span2 span2 = cspan_at3(&span3, 4);
         printf("\niterate span2: ");
         c_FOREACH (i, Span2, span2)
             printf("%g ", *i.ref);
diff --git a/include/stc/cspan.h b/include/stc/cspan.h
index 5ba408a8..2b600a2a 100644
--- a/include/stc/cspan.h
+++ b/include/stc/cspan.h
@@ -94,6 +94,9 @@ int demo2() {
 #define cspan_init(SpanType, ...) \
     {.data=(SpanType##_value[])__VA_ARGS__, .dim={sizeof((SpanType##_value[])__VA_ARGS__)/sizeof(SpanType##_value)}}
 
+#define cspan_flatten(span) \
+    {.data=(span)->data, .dim={(uint32_t)cspan_size(span)}}
+
 /* create a cspan from a cvec, cstack, cdeq, cqueue, or cpque (heap) */
 #define cspan_from(container) \
     {.data=(container)->data, .dim={(uint32_t)(container)->_len}}
@@ -124,19 +127,19 @@ int demo2() {
 #define cspan_subspan4(self, offset, count) \
     {.data=cspan_at(self, offset, 0, 0, 0), .dim={count, (self)->dim[1], (self)->dim[2], (self)->dim[3]}}
 
-#define cspan_subdim4(...) c_MACRO_OVERLOAD(cspan_subdim4, __VA_ARGS__)
-#define cspan_subdim3(...) c_MACRO_OVERLOAD(cspan_subdim3, __VA_ARGS__)
-#define cspan_subdim2(self, x) \
+#define cspan_at4(...) c_MACRO_OVERLOAD(cspan_at4, __VA_ARGS__)
+#define cspan_at3(...) c_MACRO_OVERLOAD(cspan_at3, __VA_ARGS__)
+#define cspan_at2(self, x) \
     {.data=cspan_at(self, x, 0), .dim={(self)->dim[1]}}
-#define cspan_subdim3_2(self, x) \
+#define cspan_at3_2(self, x) \
     {.data=cspan_at(self, x, 0, 0), .dim={(self)->dim[1], (self)->dim[2]}}
-#define cspan_subdim3_3(self, x, y) \
+#define cspan_at3_3(self, x, y) \
     {.data=cspan_at(self, x, y, 0), .dim={(self)->dim[2]}}
-#define cspan_subdim4_2(self, x) \
+#define cspan_at4_2(self, x) \
     {.data=cspan_at(self, x, 0, 0, 0), .dim={(self)->dim[1], (self)->dim[2], (self)->dim[3]}}
-#define cspan_subdim4_3(self, x, y) \
+#define cspan_at4_3(self, x, y) \
     {.data=cspan_at(self, x, y, 0, 0), .dim={(self)->dim[2], (self)->dim[3]}}
-#define cspan_subdim4_4(self, x, y, z) \
+#define cspan_at4_4(self, x, y, z) \
     {.data=cspan_at(self, x, y, z, 0), .dim={(self)->dim[3]}}
 
 STC_INLINE size_t _cspan_i1(const uint32_t dim[1], uint32_t x)
diff --git a/misc/examples/multidim.c b/misc/examples/multidim.c
index 69f818cc..3eef1497 100644
--- a/misc/examples/multidim.c
+++ b/misc/examples/multidim.c
@@ -31,7 +31,7 @@ int main()
     puts("");
 
     // or iterate a subspan...
-    ispan2 sub = cspan_subdim3(&ms3, 1);
+    ispan2 sub = cspan_at3(&ms3, 1);
     printf("sub: ");
     c_FOREACH (i, ispan2, sub)
         printf(" %d", *i.ref);