JW_OBJ

Documentation

API Reference

JW_OBJ

Description

Begin a JSON object and write key-value entries using JW_*_KV macros. This macro must be used as a wrapper for other JW_*_KV macros to generate a JSON object. Tracks whether commas are needed between entries using an internal flag.

Parameters

Name	Direction	Description
`writer`	in	A block of code containing `JW_*_KV` calls for populating the object.

Usage example (from documentation)

  JW_OBJ(json, {
      JW_STR_KV(json, "name", obj.name);
      JW_INT_KV(json, "ref", obj.ref);
  });

Success

Appends a valid JSON object to json

Failure

Does not return on failure (relies on internal string operations)

Usage example (Cross-references)

Usage examples (Cross-references)

In Write.Nested.c:147:

        };
    
        JW_OBJ(json, {
            JW_OBJ_KV(json, "user", {
                JW_INT_KV(json, "id", data.user.id);

In Write.Nested.c:191:

        };
    
        JW_OBJ(json, {
            JW_OBJ_KV(json, "company", {
                JW_OBJ_KV(json, "departments", {

In Write.Nested.c:240:

        VecPushBack(&response.data, sym);
    
        JW_OBJ(json, {
            JW_BOOL_KV(json, "status", response.status);
            JW_STR_KV(json, "message", response.message);

In Write.Nested.c:303:

        VecPushBack(&functions, func2);
    
        JW_OBJ(json, {
            JW_ARR_KV(json, "functions", functions, func, {
                JW_OBJ(json, {

In Write.Nested.c:305:

        JW_OBJ(json, {
            JW_ARR_KV(json, "functions", functions, func, {
                JW_OBJ(json, {
                    JW_INT_KV(json, "id", func.id);
                    JW_STR_KV(json, "name", func.name);

In Write.Nested.c:352:

        result.owned_by   = StrInitFromZstr("user1");
    
        JW_OBJ(json, {
            JW_INT_KV(json, "binary_id", result.binary_id);
            JW_STR_KV(json, "binary_name", result.binary_name);

In Write.Nested.c:406:

        VecPushBack(&symbols, sym2);
    
        JW_OBJ(json, {
            JW_OBJ_KV(json, "functions", {
                VecForeach(&symbols, symbol) {

In Write.Nested.c:452:

        Str test_name    = StrInitFromZstr("test");
    
        JW_OBJ(json, {
            JW_OBJ_KV(json, "level1", {
                JW_OBJ_KV(json, "level2", {

In Write.Nested.c:507:

        VecPushBack(&booleans, bool3);
    
        JW_OBJ(json, {
            JW_ARR_KV(json, "numbers", numbers, num, { JW_INT(json, num); });
            JW_ARR_KV(json, "strings", strings, str, { JW_STR(json, str); });

In Write.EdgeCases.c:79:

    
        // Write completely empty object
        JW_OBJ(
            json,
            {

In Write.EdgeCases.c:105:

        Vec(Str) empty_strings = VecInitWithDeepCopy(NULL, StrDeinit);
    
        JW_OBJ(json, {
            JW_ARR_KV(json, "numbers", empty_numbers, num, { JW_INT(json, num); });
            JW_ARR_KV(json, "strings", empty_strings, str, { JW_STR(json, str); });

In Write.EdgeCases.c:131:

        Str empty_desc = StrInit();
    
        JW_OBJ(json, {
            JW_STR_KV(json, "name", empty_name);
            JW_STR_KV(json, "description", empty_desc);

In Write.EdgeCases.c:158:

        f64 delta   = -0.001;
    
        JW_OBJ(json, {
            JW_INT_KV(json, "temp", temp);
            JW_FLT_KV(json, "balance", balance);

In Write.EdgeCases.c:184:

        f64 small_float = 2.2250738585072014e-308;
    
        JW_OBJ(json, {
            JW_INT_KV(json, "big_int", big_int);
            JW_FLT_KV(json, "big_float", big_float);

In Write.EdgeCases.c:215:

        bool bool_false = false;
    
        JW_OBJ(json, {
            JW_INT_KV(json, "int_zero", int_zero);
            JW_FLT_KV(json, "float_zero", float_zero);

In Write.EdgeCases.c:242:

        Str data    = StrInitFromZstr("line1\nline2\ttab");
    
        JW_OBJ(json, {
            JW_STR_KV(json, "path", path);
            JW_STR_KV(json, "message", message);

In Write.EdgeCases.c:278:

        Str tab       = StrInitFromZstr("\t");
    
        JW_OBJ(json, {
            JW_STR_KV(json, "quotes", quotes);
            JW_STR_KV(json, "backslash", backslash);

In Write.EdgeCases.c:312:

        Vec(i32) empty_list = VecInit();
    
        JW_OBJ(json, {
            JW_OBJ_KV(
                json,

In Write.EdgeCases.c:357:

        i32 x_value = 1;
    
        JW_OBJ(json, {
            JW_OBJ_KV(
                json,

In Write.EdgeCases.c:393:

        i64 minus_one = -1;
    
        JW_OBJ(json, {
            JW_INT_KV(json, "max_int", max_int);
            JW_INT_KV(json, "min_int", min_int);

In Write.EdgeCases.c:421:

        f64 negative_tiny = -0.000001;
    
        JW_OBJ(json, {
            JW_FLT_KV(json, "tiny", tiny);
            JW_FLT_KV(json, "huge", huge);

In Write.EdgeCases.c:452:

        // Single integer
        i32 single_int = 42;
        JW_OBJ(json1, { JW_INT_KV(json1, "value", single_int); });
    
        // Single string

In Write.EdgeCases.c:456:

        // Single string
        Str single_str = StrInitFromZstr("hello");
        JW_OBJ(json2, { JW_STR_KV(json2, "text", single_str); });
    
        // Single boolean

In Write.EdgeCases.c:460:

        // Single boolean
        bool single_bool = true;
        JW_OBJ(json3, { JW_BOOL_KV(json3, "flag", single_bool); });
    
        // Single float

In Write.EdgeCases.c:464:

        // Single float
        f64 single_float = 3.14;
        JW_OBJ(json4, { JW_FLT_KV(json4, "pi", single_float); });
    
        const char *expected1 = "{\"value\":42}";

In Write.Simple.c:111:

        Str city = StrInitFromZstr("New York");
    
        JW_OBJ(json, {
            JW_STR_KV(json, "name", name);
            JW_STR_KV(json, "city", city);

In Write.Simple.c:138:

        u32 year  = 2024;
    
        JW_OBJ(json, {
            JW_INT_KV(json, "count", count);
            JW_FLT_KV(json, "score", score);

In Write.Simple.c:163:

        bool visible = false;
    
        JW_OBJ(json, {
            JW_BOOL_KV(json, "enabled", enabled);
            JW_BOOL_KV(json, "visible", visible);

In Write.Simple.c:186:

        Person person = {1001, StrInitFromZstr("Bob"), 25, true, 50000.0};
    
        JW_OBJ(json, {
            JW_INT_KV(json, "id", person.id);
            JW_STR_KV(json, "name", person.name);

In Write.Simple.c:213:

        Config config = {false, 30, StrInitFromZstr("INFO")};
    
        JW_OBJ(json, {
            JW_BOOL_KV(json, "debug_mode", config.debug_mode);
            JW_INT_KV(json, "timeout", config.timeout);

In Write.Simple.c:247:

        VecPushBack(&languages, lang3);
    
        JW_OBJ(json, { JW_ARR_KV(json, "languages", languages, lang, { JW_STR(json, lang); }); });
    
        const char *expected = "{\"languages\":[\"C\",\"Python\",\"Rust\"]}";

In Write.Simple.c:277:

        };
    
        JW_OBJ(json, {
            JW_OBJ_KV(json, "user", {
                JW_STR_KV(json, "name", data.user.name);

In Write.Simple.c:318:

        VecPushBack(&product.tags, tag3);
    
        JW_OBJ(json, {
            JW_INT_KV(json, "id", product.id);
            JW_STR_KV(json, "name", product.name);

In RoundTrip.c:100:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_INT_KV(json, "count", original.count);
            JW_FLT_KV(json, "temperature", original.temperature);

In RoundTrip.c:172:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_INT_KV(json, "big_int", original.big_int);
            JW_INT_KV(json, "negative_int", original.negative_int);

In RoundTrip.c:242:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_BOOL_KV(json, "flag1", original.flag1);
            JW_BOOL_KV(json, "flag2", original.flag2);

In RoundTrip.c:299:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_STR_KV(json, "empty", original.empty);
            JW_STR_KV(json, "simple", original.simple);

In RoundTrip.c:374:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_ARR_KV(json, "numbers", original_numbers, num, { JW_INT(json, num); });
            JW_ARR_KV(json, "strings", original_strings, str, { JW_STR(json, str); });

In RoundTrip.c:459:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_OBJ_KV(json, "user", {
                JW_INT_KV(json, "id", original_person.id);

In RoundTrip.c:538:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_OBJ_KV(json, "user", {
                JW_INT_KV(json, "id", original.user.id);

In RoundTrip.c:654:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_STR_KV(json, "empty_string", empty_str);
            JW_ARR_KV(json, "empty_numbers", empty_numbers, num, { JW_INT(json, num); });

In RoundTrip.c:734:

        // Write to JSON
        Str json = StrInit();
        JW_OBJ(json, {
            JW_INT_KV(json, "max_int", original.max_int);
            JW_INT_KV(json, "min_int", original.min_int);

In JSON.h:706:

            }                                                                                                              \
            StrAppendf(&(j), "\"%s\":", k);                                                                                \
            JW_OBJ(j, writer);                                                                                             \
        } while (0)

Last updated on April 20, 2026

JW_INT_KV JW_OBJ_KV