nano/examples/json.nano

print("=== JSON Encoder Demo ===");
print("");

class JSONEncoder {
    JSONEncoder(this) {
    }

    encode(this, value) {
        t = typeof(value);
        if (t == "null") {
            return "null";
        }
        if (t == "int" || t == "float") {
            return str(value);
        }
        if (t == "str") {
            return "\"" + value + "\"";
        }
        if (t == "array") {
            return this.encodeArray(value);
        }
        return "null";
    }

    encodeArray(this, arr) {
        result = "[";
        for (i = 0; i < len(arr); i++) {
            if (i > 0) {
                result += ",";
            }
            result += this.encode(arr[i]);
        }
        result += "]";
        return result;
    }
}

encoder = new JSONEncoder();

print("Encoding primitives:");
print("  null ->", encoder.encode(null));
print("  42 ->", encoder.encode(42));
print("  3.14 ->", encoder.encode(3.14));
print("  \"hello\" ->", encoder.encode("hello"));

print("");
print("Encoding arrays:");
arr = {1, 2, 3};
print("  {1, 2, 3} ->", encoder.encodeArray(arr));

mixed = {1, "two", 3};
print("  {1, \"two\", 3} ->", encoder.encodeArray(mixed));

print("");
print("=== JSON Decoder Demo ===");
print("");

class JSONDecoder {
    input = "";
    pos = 0;

    JSONDecoder(this) {
    }

    decode(this, jsonStr) {
        this.input = jsonStr;
        this.pos = 0;
        return this.parseValue();
    }

    parseValue(this) {
        this.skipWhitespace();
        if (this.pos >= this.input.length) {
            return null;
        }
        c = this.input.substr(this.pos, 1);
        if (c == "[") {
            return this.parseArray();
        }
        if (c == "n") {
            this.pos += 4;
            return null;
        }
        return this.parseNumber();
    }

    parseNumber(this) {
        start = this.pos;
        while (this.pos < this.input.length) {
            c = this.input.substr(this.pos, 1);
            isDigit = (c == "0" || c == "1" || c == "2" || c == "3" || c == "4" || c == "5" || c == "6" || c == "7" || c == "8" || c == "9" || c == "-");
            if (isDigit == 0) {
                break;
            }
            this.pos++;
        }
        numStr = this.input.substr(start, this.pos - start);
        return int(numStr);
    }

    parseArray(this) {
        this.pos++;
        result = {};
        this.skipWhitespace();
        if (this.pos < this.input.length) {
            c = this.input.substr(this.pos, 1);
            if (c == "]") {
                this.pos++;
                return result;
            }
        }
        while (this.pos < this.input.length) {
            value = this.parseValue();
            result.push(value);
            this.skipWhitespace();
            if (this.pos >= this.input.length) {
                break;
            }
            c = this.input.substr(this.pos, 1);
            if (c == "]") {
                this.pos++;
                break;
            }
            if (c == ",") {
                this.pos++;
            }
        }
        return result;
    }

    skipWhitespace(this) {
        while (this.pos < this.input.length) {
            c = this.input.substr(this.pos, 1);
            if (c != " ") {
                break;
            }
            this.pos++;
        }
    }
}

decoder = new JSONDecoder();

print("Decoding numbers:");
print("  \"123\" ->", decoder.decode("123"));
print("  \"456\" ->", decoder.decode("456"));

print("");
print("Decoding arrays:");
decoded = decoder.decode("[1,2,3]");
print("  \"[1,2,3]\" -> length:", len(decoded));
print("    element 0:", decoded[0]);
print("    element 1:", decoded[1]);
print("    element 2:", decoded[2]);

print("");
print("All JSON tests completed");