Support for linking dependant UTF8 and cstr functions and/or cregex.c by defining i_extern before including <stc/cstr.h> and <stc/cregex.h>. I.e.

#define i_extern
#define i_implement // define cstr functions as shared symbols (static if not defined).
#include <stc/cregex.h> // include cstr.h, utf8code.c, cregex.c, unless already included.

13 files changed, 74 insertions, 75 deletions

diff --git a/examples/forfilter.c b/examples/forfilter.c
index 25ed07cd..bf486ea4 100644
--- a/examples/forfilter.c
+++ b/examples/forfilter.c
@@ -1,5 +1,5 @@
 #include <stdio.h>
-#define i_implement
+#define i_extern
 #include <stc/cstr.h>
 #include <stc/csview.h>
 #include <stc/views.h>
@@ -142,5 +142,3 @@ int main(void)
     demo4();
     demo5();
 }
-
-#include "../src/utf8code.c"
diff --git a/examples/regex1.c b/examples/regex1.c
index d1f061fb..47cce4cf 100644
--- a/examples/regex1.c
+++ b/examples/regex1.c
@@ -1,5 +1,4 @@
-#define i_implement
-#include <stc/cstr.h>
+#define i_extern
 #include <stc/cregex.h>
 
 int main(int argc, char* argv[])
@@ -29,6 +28,3 @@ int main(int argc, char* argv[])
         }
     }
 }
-
-#include "../src/cregex.c"
-#include "../src/utf8code.c"
diff --git a/examples/regex2.c b/examples/regex2.c
index 6dffc8c4..8c4df420 100644
--- a/examples/regex2.c
+++ b/examples/regex2.c
@@ -1,5 +1,4 @@
-#define i_implement
-#include <stc/cstr.h>
+#define i_extern
 #include <stc/cregex.h>
 
 int main()
@@ -31,6 +30,3 @@ int main()
         }
     }
 }
-
-#include "../src/cregex.c"
-#include "../src/utf8code.c"
diff --git a/examples/regex_match.c b/examples/regex_match.c
index da23b3a2..fd4315ad 100644
--- a/examples/regex_match.c
+++ b/examples/regex_match.c
@@ -1,7 +1,6 @@
-#define i_implement
-#include <stc/cstr.h>
-#include <stc/csview.h>
+#define i_extern
 #include <stc/cregex.h>
+#include <stc/csview.h>
 #define i_val float
 #include <stc/cstack.h>
 
@@ -33,6 +32,3 @@ int main()
         printf("\n%s\n", cstr_str(&nums));
     }
 }
-
-#include "../src/cregex.c"
-#include "../src/utf8code.c"
diff --git a/examples/regex_replace.c b/examples/regex_replace.c
index 13bc9bf0..4091a59e 100644
--- a/examples/regex_replace.c
+++ b/examples/regex_replace.c
@@ -1,7 +1,6 @@
-#define i_implement
-#include <stc/cstr.h>
-#include <stc/csview.h>
+#define i_extern
 #include <stc/cregex.h>
+#include <stc/csview.h>
 
 bool add_10_years(int i, csview m, cstr* mstr) {
     if (i == 1) { // group 1 matches year
@@ -52,6 +51,3 @@ int main()
         printf("curly: %s\n", cstr_str(&str));
     }
 }
-
-#include "../src/cregex.c"
-#include "../src/utf8code.c"
diff --git a/examples/splitstr.c b/examples/splitstr.c
index 27dd308c..a7b386f3 100644
--- a/examples/splitstr.c
+++ b/examples/splitstr.c
@@ -1,8 +1,7 @@
 #include <stdio.h>
-#define i_implement // cstr functions
-#include <stc/cstr.h>
-#include <stc/csview.h>
+#define i_extern // cstr + utf8 functions
 #include <stc/cregex.h>
+#include <stc/csview.h>
 
 int main()
 {
@@ -18,6 +17,3 @@ int main()
         c_formatch (i, &re, "  Hello   World      C99! ")
             printf("'%.*s'\n", c_ARGsv(i.match[0]));
 }
-
-#include "../src/cregex.c"
-#include "../src/utf8code.c"
diff --git a/examples/utf8replace_c.c b/examples/utf8replace_c.c
index b43aab6f..be77d615 100644
--- a/examples/utf8replace_c.c
+++ b/examples/utf8replace_c.c
@@ -1,9 +1,9 @@
-#define i_implement
+#define i_extern // add utf8 dependencies
 #include <stc/cstr.h>
 #include <stc/csview.h>
 
 int main() {
-    c_auto (cstr, hello) {
+    c_auto (cstr, hello, upper) {
         hello = cstr_new("hell😀 w😀rld");
         printf("%s\n", cstr_str(&hello));
 
@@ -14,6 +14,8 @@ int main() {
         cstr_replace(&hello, "🐨", "ø", 1);
         printf("%s\n", cstr_str(&hello));
 
+        upper = cstr_toupper_sv(cstr_sv(&hello));
+
         c_foreach (c, cstr, hello)
             printf("%.*s,", c_ARGsv(c.u8.chr));
         puts("");
diff --git a/include/stc/cregex.h b/include/stc/cregex.h
index 43dc7ac0..877f4052 100644
--- a/include/stc/cregex.h
+++ b/include/stc/cregex.h
@@ -22,8 +22,8 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
-#ifndef CREGEX_H_
-#define CREGEX_H_
+#ifndef CREGEX_H_INCLUDED
+#define CREGEX_H_INCLUDED
 /*
  * cregex.h
  * 
@@ -135,4 +135,13 @@ cstr cregex_replace_pattern(const char* pattern, const char* input, const char*
 /* destroy regex */
 void cregex_drop(cregex* self);
 
+#endif // CREGEX_H_INCLUDED
+#if defined i_extern || defined STC_EXTERN
+#  include "../src/cregex.c"
+#  include "../src/utf8code.c"
 #endif
+#undef i_opt
+#undef i_header
+#undef i_static
+#undef i_implement
+#undef i_extern
diff --git a/include/stc/cstr.h b/include/stc/cstr.h
index bf58444c..8a351d02 100644
--- a/include/stc/cstr.h
+++ b/include/stc/cstr.h
@@ -27,6 +27,9 @@
 #ifndef CSTR_H_INCLUDED
 #define CSTR_H_INCLUDED
 
+#if defined i_extern || defined STC_EXTERN
+#  define _i_extern
+#endif
 #include "ccommon.h"
 #include "forward.h"
 #include "utf8.h"
@@ -405,8 +408,38 @@ STC_INLINE bool cstr_getline(cstr *self, FILE *fp)
 
 STC_API uint64_t cstr_hash(const cstr *self);
 
+#ifdef _i_extern
+static struct {
+    int      (*conv_asc)(int);
+    uint32_t (*conv_utf)(uint32_t);
+}
+fn_tocase[] = {{tolower, utf8_casefold},
+               {tolower, utf8_tolower},
+               {toupper, utf8_toupper}};
+
+cstr cstr_tocase(csview sv, int k) {
+    cstr out = cstr_init();
+    char *buf = cstr_reserve(&out, sv.size*3/2);
+    uint32_t cp; size_t sz = 0;
+    utf8_decode_t d = {.state=0};
+
+    while (*sv.str) {
+        do { utf8_decode(&d, (uint8_t)*sv.str++); } while (d.state);
+        if (d.codep < 128)
+            buf[sz++] = (char)fn_tocase[k].conv_asc((int)d.codep);
+        else {
+            cp = fn_tocase[k].conv_utf(d.codep);
+            sz += utf8_encode(buf + sz, cp);
+        }
+    }
+    _cstr_set_size(&out, sz);
+    cstr_shrink_to_fit(&out);
+    return out;
+}
+#endif
+
 /* -------------------------- IMPLEMENTATION ------------------------- */
-#if defined(i_implement) || defined(i_extern)
+#if defined(i_implement)
 
 STC_DEF uint64_t cstr_hash(const cstr *self) {
     csview sv = cstr_sv(self);
@@ -627,4 +660,4 @@ STC_DEF size_t cstr_printf(cstr* self, const char* fmt, ...) {
 #undef i_header
 #undef i_static
 #undef i_implement
-#undef i_extern
+#undef _i_extern
diff --git a/include/stc/csview.h b/include/stc/csview.h
index 149759ce..4bd37173 100644
--- a/include/stc/csview.h
+++ b/include/stc/csview.h
@@ -160,7 +160,7 @@ STC_INLINE bool csview_eq(const csview* x, const csview* y)
 STC_API uint64_t csview_hash(const csview *self);
 
 /* -------------------------- IMPLEMENTATION ------------------------- */
-#if defined(i_implement) || defined(i_extern)
+#if defined(i_implement)
 
 STC_DEF size_t csview_find_sv(csview sv, csview search) {
     char* res = cstrnstrn(sv.str, search.str, sv.size, search.size);
diff --git a/include/stc/utf8.h b/include/stc/utf8.h
index 0ff79fb9..ab39f3ba 100644
--- a/include/stc/utf8.h
+++ b/include/stc/utf8.h
@@ -1,8 +1,8 @@
 #ifndef UTF8_H_INCLUDED
 #define UTF8_H_INCLUDED
 
+#include "forward.h"
 #include "ccommon.h"
-#include <ctype.h>
 
 // utf8 methods defined in src/utf8code.c:
 
@@ -88,4 +88,8 @@ STC_INLINE const char* utf8_at(const char *s, size_t index) {
 STC_INLINE size_t utf8_pos(const char* s, size_t index)
     { return (size_t)(utf8_at(s, index) - s); }
 
-#endif
+#endif // UTF8_H_INCLUDED
+#if defined i_extern || defined STC_EXTERN
+#  include "../src/utf8code.c"
+#  undef i_extern
+#endif
\ No newline at end of file
diff --git a/src/cregex.c b/src/cregex.c
index 358e299d..1747ed3f 100644
--- a/src/cregex.c
+++ b/src/cregex.c
@@ -23,11 +23,10 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
-
-#include <stc/cregex.h>
-#include <stc/utf8.h>
-#define i_header
+#ifndef CREGEX_C_INCLUDED
+#define CREGEX_C_INCLUDED
 #include <stc/cstr.h>
+#include <stc/cregex.h> // header only
 #include <setjmp.h>
 #include <ctype.h>
 
@@ -1260,3 +1259,4 @@ void
 cregex_drop(cregex* self) {
     c_free(self->prog);
 }
+#endif
\ No newline at end of file
diff --git a/src/utf8code.c b/src/utf8code.c
index b1534230..5dfb7d30 100644
--- a/src/utf8code.c
+++ b/src/utf8code.c
@@ -1,7 +1,7 @@
+#ifndef UTF8_C_INCLUDED
+#define UTF8_C_INCLUDED
 #include <ctype.h>
-#define i_header
-#include <stc/cstr.h>
-#include <stc/cregex.h>
+#include <stc/utf8.h> // header only
 #include "utf8tabs.inc"
 
 const uint8_t utf8_dtab[] = {
@@ -143,31 +143,4 @@ bool utf8_isalpha(uint32_t c) {
     if (c < 128) return isalpha(c) != 0;
     return utf8_islower(c) || utf8_isupper(c);
 }
-
-static struct {
-    int      (*conv_asc)(int);
-    uint32_t (*conv_utf)(uint32_t);
-}
-fn_tocase[] = {{tolower, utf8_casefold},
-               {tolower, utf8_tolower},
-               {toupper, utf8_toupper}};
-
-cstr cstr_tocase(csview sv, int k) {
-    cstr out = cstr_null;
-    char *buf = cstr_reserve(&out, sv.size*3/2);
-    uint32_t cp; size_t sz = 0;
-    utf8_decode_t d = {.state=0};
-
-    while (*sv.str) {
-        do { utf8_decode(&d, (uint8_t)*sv.str++); } while (d.state);
-        if (d.codep < 128)
-            buf[sz++] = (char)fn_tocase[k].conv_asc((int)d.codep);
-        else {
-            cp = fn_tocase[k].conv_utf(d.codep);
-            sz += utf8_encode(buf + sz, cp);
-        }
-    }
-    _cstr_set_size(&out, sz);
-    cstr_shrink_to_fit(&out);
-    return out;
-}
+#endif