kjuulh/rhai
1
0
Fork 0
Code Issues 1 Pull Requests 1 Packages Projects Releases Wiki Activity

Edit documentation.

Browse Source
This commit is contained in:
Stephen Chung
2020-06-22 00:03:45 +08:00
parent 7cc1a3f5dc
commit d728ac6758
37 changed files with 386 additions and 147 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
doc/src/language/statements.md
View File

@@ -3,13 +3,14 @@ Statements
{{#include ../links.md}}
Terminated by '`;`'
------------------
Statements are terminated by semicolons '`;`' and they are mandatory,
except for the _last_ statement in a _block_ (enclosed by '`{`' .. '`}`' pairs) where it can be omitted.
A statement can be used anywhere where an expression is expected. These are called, for lack of a more
creative name, "statement expressions." The _last_ statement of a statement block is _always_ the block's
return value when used as a statement.
If the last statement has no return value (e.g. variable definitions, assignments) then it is assumed to be [`()`].
Semicolons can also be omitted if the statement contains a block itself
(e.g. the `if`, `while`, `for` and `loop` statements).
```rust
let a = 42; // normal assignment statement
@@ -20,6 +21,20 @@ let a = { 40 + 2 }; // 'a' is set to the value of the statement block, which
// ^ the last statement does not require a terminating semicolon (although it also works with it)
// ^ semicolon required here to terminate the assignment statement; it is a syntax error without it
4 * 10 + 2 // a statement which is just one expression; no ending semicolon is OK
if foo { a = 42 }
// ^ there is no need to terminate an if-statement with a semicolon
4 * 10 + 2 // a statement which is just one expression - no ending semicolon is OK
// because it is the last statement of the whole block
```
Statement Expression
--------------------
A statement can be used anywhere where an expression is expected. These are called, for lack of a more
creative name, "statement expressions."
The _last_ statement of a statement block is _always_ the block's return value when used as a statement.
If the last statement has no return value (e.g. variable definitions, assignments) then it is assumed to be [`()`].