feat: add utility function to dump any internal object as JSON

1 files changed, 107 insertions, 0 deletions

diff --git a/src/json.c b/src/json.c
new file mode 100644
index 0000000..8abeea7
--- /dev/null
+++ b/src/json.c
@@ -0,0 +1,107 @@
+#include "json.h"
+#include "common.h"
+
+struct JsonBuilder {
+    StrBuilder buf;
+    BOOL has_output_element[256];
+    int depth;
+};
+
+JsonBuilder* jsonbuilder_new() {
+    JsonBuilder* b = calloc(1, sizeof(JsonBuilder));
+    strbuilder_init(&b->buf);
+    return b;
+}
+
+const char* jsonbuilder_get_output(JsonBuilder* b) {
+    return b->buf.buf;
+}
+
+static void emit_comma_if_needed(JsonBuilder* b) {
+    if (b->has_output_element[b->depth - 1]) {
+        strbuilder_append_char(&b->buf, ',');
+    }
+}
+
+void jsonbuilder_object_start(JsonBuilder* b) {
+    strbuilder_append_char(&b->buf, '{');
+    b->has_output_element[b->depth++] = FALSE;
+}
+
+void jsonbuilder_object_end(JsonBuilder* b) {
+    b->depth--;
+    strbuilder_append_char(&b->buf, '}');
+}
+
+void jsonbuilder_object_member_start(JsonBuilder* b, const char* key) {
+    emit_comma_if_needed(b);
+    jsonbuilder_string(b, key);
+    strbuilder_append_char(&b->buf, ':');
+}
+
+void jsonbuilder_object_member_end(JsonBuilder* b) {
+    b->has_output_element[b->depth - 1] = TRUE;
+}
+
+void jsonbuilder_array_start(JsonBuilder* b) {
+    strbuilder_append_char(&b->buf, '[');
+    b->has_output_element[b->depth++] = FALSE;
+}
+
+void jsonbuilder_array_end(JsonBuilder* b) {
+    b->depth--;
+    strbuilder_append_char(&b->buf, ']');
+}
+
+void jsonbuilder_array_element_start(JsonBuilder* b) {
+    emit_comma_if_needed(b);
+}
+
+void jsonbuilder_array_element_end(JsonBuilder* b) {
+    b->has_output_element[b->depth - 1] = TRUE;
+}
+
+void jsonbuilder_null(JsonBuilder* b) {
+    strbuilder_append_string(&b->buf, "null");
+}
+
+void jsonbuilder_boolean(JsonBuilder* b, BOOL value) {
+    strbuilder_append_string(&b->buf, value ? "true" : "false");
+}
+
+void jsonbuilder_integer(JsonBuilder* b, int value) {
+    char buf[32];
+    sprintf(buf, "%d", value);
+    strbuilder_append_string(&b->buf, buf);
+}
+
+void jsonbuilder_string(JsonBuilder* b, const char* value) {
+    if (!value) {
+        jsonbuilder_null(b);
+        return;
+    }
+
+    strbuilder_append_char(&b->buf, '"');
+
+    for (const char* p = value; *p; p++) {
+        if (*p == '"') {
+            strbuilder_append_string(&b->buf, "\\\"");
+        } else if (*p == '\\') {
+            strbuilder_append_string(&b->buf, "\\\\");
+        } else if (*p == '\b') {
+            strbuilder_append_string(&b->buf, "\\b");
+        } else if (*p == '\f') {
+            strbuilder_append_string(&b->buf, "\\f");
+        } else if (*p == '\n') {
+            strbuilder_append_string(&b->buf, "\\n");
+        } else if (*p == '\r') {
+            strbuilder_append_string(&b->buf, "\\r");
+        } else if (*p == '\t') {
+            strbuilder_append_string(&b->buf, "\\t");
+        } else {
+            strbuilder_append_char(&b->buf, *p);
+        }
+    }
+
+    strbuilder_append_char(&b->buf, '"');
+}