diff options
Diffstat (limited to 'doc/tutorial.md')
| -rw-r--r-- | doc/tutorial.md | 41 |
1 files changed, 21 insertions, 20 deletions
diff --git a/doc/tutorial.md b/doc/tutorial.md index 3d649a07bf8..0ca7a39b497 100644 --- a/doc/tutorial.md +++ b/doc/tutorial.md @@ -204,16 +204,13 @@ paretheses, while their bodies *must* be wrapped in brackets. Single-statement, bracket-less bodies are not allowed. ~~~~ -# fn calibrate_universe() -> bool { false } -# fn party_on() {} -# fn panic() {} +# fn recalibrate_universe() -> bool { true } fn main() { - while calibrate_universe() { - /* Ensure that basic math still operates is expected */ - if 2*20 > 30 { - party_on(); // That's a relief - } else { - panic(); + /* A simple loop */ + loop { + // A tricky calculation + if recalibrate_universe() { + return; } } } @@ -438,10 +435,9 @@ The nil literal is written just like the type: `()`. The keywords Character literals are written between single quotes, as in `'x'`. Just as in C, Rust understands a number of character escapes, using the backslash -character, `\n`, `\r`, and `\t` being the most common. - -String literals allow the same escape sequences. They are written -between double quotes (`"hello"`). Rust strings may contain newlines. +character, `\n`, `\r`, and `\t` being the most common. String literals, +written between double quotes, allow the same escape sequences. Rust strings +may contain newlines. ## Operators @@ -482,14 +478,19 @@ a syntax extension is being used, the names of all syntax extensions end with which is `fmt!`, a `sprintf`-style text formatter that is expanded at compile time. -~~~~ -io::println(fmt!("%s is %d", ~"the answer", 42)); -~~~~ - `fmt!` supports most of the directives that [printf][pf] supports, but will give you a compile-time error when the types of the directives don't match the types of the arguments. +~~~~ +# let mystery_object = (); + +io::println(fmt!("%s is %d", "the answer", 43)); + +// %? will conveniently print any type +io::println(fmt!("what is this thing: %?", mystery_object)); +~~~~ + [pf]: http://en.cppreference.com/w/cpp/io/c/fprintf You can define your own syntax extensions with the macro system, which is out @@ -505,11 +506,11 @@ compulsory, an optional `else` clause can be appended, and multiple ~~~~ if false { - io::println(~"that's odd"); + io::println("that's odd"); } else if true { - io::println(~"right"); + io::println("right"); } else { - io::println(~"neither true nor false"); + io::println("neither true nor false"); } ~~~~ |