Console
console methods compile to Rust's print macros and standard output.
Basic output
console.log("hello"); // println!("hello")
console.error("fail"); // eprintln!("fail")
console.warn("caution"); // eprintln!("[WARN] caution")
console.debug("trace"); // println!("[DEBUG] trace")
console.log prints to stdout. console.error and console.warn print to stderr.
Structured output
const data = { name: "Alice", age: 30 };
console.table(data); // Pretty-printed with {:#?}
console.dir(data); // Same as table
Assertions
console.assert(x > 0, "x must be positive");
Compiles to assert!(x > 0, "{}", "x must be positive"). Panics if the condition is false.
Timers
Measure execution time:
console.time("fetch");
// ... do some work ...
console.timeLog("fetch"); // Prints elapsed so far
console.timeEnd("fetch"); // Prints final elapsed time
Counters
console.count("loop"); // "loop: 1"
console.count("loop"); // "loop: 2"
console.count("loop"); // "loop: 3"
console.countReset("loop"); // Resets to 0
console.count("loop"); // "loop: 1"
Grouping
console.group("Section");
console.log("inside group");
console.groupEnd();
Other
console.clear(); // ANSI clear screen
console.trace(); // Prints "Trace"
Complete reference
| Method | Rust output |
|--------|-------------|
| console.log(value) | println!("{}", value) |
| console.error(value) | eprintln!("{}", value) |
| console.warn(value) | eprintln!("[WARN] {}", value) |
| console.debug(value) | println!("[DEBUG] {}", value) |
| console.table(value) | println!("{:#?}", value) |
| console.dir(value) | println!("{:#?}", value) |
| console.assert(cond, msg) | assert!(cond, "{}", msg) |
| console.time(label) | Starts a timer |
| console.timeEnd(label) | Prints elapsed, removes timer |
| console.timeLog(label) | Prints current elapsed |
| console.count(label) | Increments and prints counter |
| console.countReset(label) | Resets counter to 0 |
| console.group(label) | Prints group header |
| console.groupEnd() | No-op |
| console.clear() | ANSI clear sequence |
| console.trace() | Prints "Trace" |