Added cregex_replace*() [implemented in utf8code.c]. Added examples/regex_replace.c. Docs not ready, i.e. API not fixed. Some other refactoring and minor fixes/improvements. cstr_assign_sv() now returns char* like the other cstr_assign*().

1 files changed, 74 insertions, 1 deletions

diff --git a/src/utf8code.c b/src/utf8code.c
index dff10409..44120cee 100644
--- a/src/utf8code.c
+++ b/src/utf8code.c
@@ -1,6 +1,7 @@
 #include <ctype.h>
 #define i_header
 #include <stc/cstr.h>
+#include <stc/cregex.h>
 #include "utf8tabs.inc"
 
 const uint8_t utf8_dtab[] = {
@@ -16,7 +17,7 @@ const uint8_t utf8_dtab[] = {
   12, 0,12,12,12,12,12, 0,12, 0,12,12, 12,24,12,12,12,12,12,24,12,24,12,12,
   12,12,12,12,12,12,12,24,12,12,12,12, 12,24,12,12,12,12,12,12,12,24,12,12,
   12,12,12,12,12,12,12,36,12,36,12,12, 12,36,12,12,12,12,12,36,12,36,12,12,
-  12,36,12,12,12,12,12,12,12,12,12,12, 
+  12,36,12,12,12,12,12,12,12,12,12,12,
 };
 
 unsigned utf8_encode(char *out, uint32_t c)
@@ -220,3 +221,75 @@ void cstr_lowercase(cstr* self) {
 void cstr_uppercase(cstr* self) {
     cstr_take(self, cstr_tocase(self, fn_toupper));
 }
+
+
+void cregex_build_replace(const char* repl, unsigned nmatch, const csview match[],
+                          cstr (*mfun)(int i, csview match), cstr* sub) {
+    cstr_clear(sub);
+    unsigned len = 0, cap = cstr_capacity(*sub);
+    char* dst = cstr_data(sub);
+
+    while (*repl != '\0') {
+        if (*repl == '\\') {
+            const char num = *++repl;
+            int i;
+            switch (num) {
+            case '0': case '1': case '2': case '3': case '4':
+            case '5': case '6': case '7': case '8': case '9':
+                i = num - '0';
+                if (i < nmatch) {
+                    csview m;
+                    cstr s = cstr_null;
+                    if (mfun) { s = mfun(i, match[i]); m = cstr_sv(&s); }
+                    else m = match[i];
+                    if (len + m.size >= cap)
+                        dst = cstr_reserve(sub, cap = cap*3/2 + m.size);
+                    for (const char* rp = m.str; rp != (m.str + m.size); ++rp)
+                        dst[len++] = *rp;
+                    cstr_drop(&s);
+                }
+                ++repl;
+            case '\0':
+                continue;
+            }
+        }
+        if (len == cap)
+            dst = cstr_reserve(sub, cap = cap*3/2 + 4);
+        dst[len++] = *repl++;
+    }
+    _cstr_set_size(sub, len);
+}
+
+
+cstr cregex_replace_re(const char* input, const cregex* re, const char* repl,
+                       cstr (*mfun)(int i, csview match), int cflags, unsigned count) {
+    cstr out = cstr_null;
+    cstr sub = cstr_null;
+    size_t from = 0;
+    csview match[cregex_MAXCAPTURES];
+    unsigned nmatch = cregex_captures(re);
+    if (!count) count = ~0;
+
+    while (count-- && cregex_match(re, input + from, nmatch, match, 0) > 0) {
+        cregex_build_replace(repl, nmatch, match, mfun, &sub);
+        const size_t pos = match[0].str - input;
+        cstr_append_n(&out, input + from, pos - from);
+        cstr_append_s(&out, sub);
+        from = pos + match[0].size;
+    }
+    cstr_append(&out, input + from);
+    cstr_drop(&sub);
+    return out;
+}
+
+
+cstr cregex_replace_fn(const char* input, const char* pattern, const char* repl,
+                       cstr (*mfun)(int i, csview match), int cflags, unsigned count) {
+    cregex re = cregex_init();
+    int res = cregex_compile(&re, pattern, cflags);
+    if (res < 0)
+        return cstr_new("[[cregex_replace_fn]]: invalid pattern");
+    cstr out = cregex_replace_re(input, &re, repl, mfun, cflags, count);
+    cregex_drop(&re);
+    return out;
+}