Nomad changes

docs/snippets/c/plugins/min_length_validator.md

@@ -0,0 +1,90 @@
+```c title="C"
+#include <kreuzberg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* user_data carries the minimum length threshold. */
+typedef struct {
+    size_t min_length;
+} MinLengthState;
+
+static char *dup_cstr(const char *s) {
+    size_t len = strlen(s);
+    char *out = (char *)malloc(len + 1);
+    if (out) {
+        memcpy(out, s, len + 1);
+    }
+    return out;
+}
+
+static int32_t validate_fn(
+    const void *user_data,
+    const char *result,
+    const char *config,
+    char **out_error
+) {
+    (void)config;
+    const MinLengthState *state = (const MinLengthState *)user_data;
+
+    /* `result` is a JSON string of ExtractionResult. We approximate the content
+     * length check by scanning for the "content" field. Production plugins
+     * should parse JSON properly. */
+    const char *content = strstr(result, "\"content\":\"");
+    size_t content_len = 0;
+    if (content) {
+        content += strlen("\"content\":\"");
+        const char *end = strchr(content, '"');
+        if (end) {
+            content_len = (size_t)(end - content);
+        }
+    }
+
+    if (content_len < state->min_length) {
+        char buf[128];
+        snprintf(buf, sizeof(buf),
+                 "Content too short: %zu < %zu characters",
+                 content_len,
+                 state->min_length);
+        *out_error = dup_cstr(buf);
+        return 1;
+    }
+    return 0;
+}
+
+static int32_t priority_fn(const void *user_data) {
+    (void)user_data;
+    return 100;
+}
+
+static void free_user_data(void *user_data) {
+    free(user_data);
+}
+
+int main(void) {
+    MinLengthState *state = (MinLengthState *)malloc(sizeof(MinLengthState));
+    state->min_length = 100;
+
+    KREUZBERGKreuzbergValidatorVTable vtable = {0};
+    vtable.validate = validate_fn;
+    vtable.priority = priority_fn;
+    vtable.free_user_data = free_user_data;
+
+    char *err = NULL;
+    int32_t rc = kreuzberg_register_validator(
+        "min-length-validator",
+        vtable,
+        state,
+        &err
+    );
+    if (rc != 0) {
+        fprintf(stderr, "register validator failed: %s\n", err ? err : "(no detail)");
+        kreuzberg_free_string(err);
+        free(state);
+        return 1;
+    }
+
+    printf("min-length-validator registered\n");
+    return 0;
+}
+```