1 files changed, 57 insertions, 0 deletions
diff --git a/misc/examples/regularexpressions/regex_replace.c b/misc/examples/regularexpressions/regex_replace.c
new file mode 100644
index 00000000..087387d7
--- /dev/null
+++ b/misc/examples/regularexpressions/regex_replace.c
@@ -0,0 +1,57 @@
+#define i_import
+#include <stc/cregex.h>
+#include <stc/csview.h>
+
+bool add_10_years(int i, csview match, cstr* out) {
+    if (i == 1) { // group 1 matches year
+        int year;
+        sscanf(match.buf, "%4d", &year); // scan 4 chars only
+        cstr_printf(out, "%04d", year + 10);
+        return true;
+    }
+    return false;
+}
+
+int main(void)
+{
+    const char* pattern = "\\b(\\d\\d\\d\\d)-(1[0-2]|0[1-9])-(3[01]|[12][0-9]|0[1-9])\\b";
+    const char* input = "start date: 2015-12-31, end date: 2022-02-28";
+    cstr str = {0};
+    cregex re = {0};
+
+    c_defer(
+        cregex_drop(&re),
+        cstr_drop(&str)
+    ){
+        printf("INPUT: %s\n", input);
+
+        /* replace with a fixed string, extended all-in-one call: */
+        cstr_take(&str, cregex_replace_pattern(pattern, input, "YYYY-MM-DD"));
+        printf("fixed: %s\n", cstr_str(&str));
+
+        /* US date format, and add 10 years to dates: */
+        cstr_take(&str, cregex_replace_pattern(pattern, input, "$1/$3/$2", 0, add_10_years, CREG_DEFAULT));
+        printf("us+10: %s\n", cstr_str(&str));
+
+        /* Wrap first date inside []: */
+        cstr_take(&str, cregex_replace_pattern(pattern, input, "[$0]"));
+        printf("brack: %s\n", cstr_str(&str));
+
+        /* Shows how to compile RE separately */
+        re = cregex_from(pattern);
+        if (cregex_captures(&re) == 0)
+            continue; /* break c_defer */
+
+        /* European date format. */
+        cstr_take(&str, cregex_replace(&re, input, "$3.$2.$1"));
+        printf("euros: %s\n", cstr_str(&str));
+
+        /* Strip out everything but the matches */
+        cstr_take(&str, cregex_replace_sv(&re, csview_from(input), "$3.$2.$1;", 0, NULL, CREG_STRIP));
+        printf("strip: %s\n", cstr_str(&str));
+
+        /* Wrap all words in ${} */
+        cstr_take(&str, cregex_replace_pattern("[a-z]+", "52 apples and 31 mangoes", "$${$0}"));
+        printf("curly: %s\n", cstr_str(&str));
+    }
+}