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Clear up the reference around let #29889

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Nov 18, 2015
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Clear up the reference around let #29889

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23 changes: 12 additions & 11 deletions src/doc/reference.md
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Original file line number Diff line number Diff line change
Expand Up @@ -2415,9 +2415,9 @@ in meaning to declaring the item outside the statement block.
> **Note**: there is no implicit capture of the function's dynamic environment when
> declaring a function-local item.

#### Variable declarations
#### `let` statements

A _variable declaration_ introduces a new set of variable, given by a pattern. The
A _`let` statement_ introduces a new set of variables, given by a pattern. The
pattern may be followed by a type annotation, and/or an initializer expression.
When no type annotation is given, the compiler will infer the type, or signal
an error if insufficient type information is available for definite inference.
Expand Down Expand Up @@ -3190,10 +3190,11 @@ let message = match maybe_digit {

### `if let` expressions

An `if let` expression is semantically identical to an `if` expression but in place
of a condition expression it expects a refutable let statement. If the value of the
expression on the right hand side of the let statement matches the pattern, the corresponding
block will execute, otherwise flow proceeds to the first `else` block that follows.
An `if let` expression is semantically identical to an `if` expression but in
place of a condition expression it expects a `let` statement with a refutable
pattern. If the value of the expression on the right hand side of the `let`
statement matches the pattern, the corresponding block will execute, otherwise
flow proceeds to the first `else` block that follows.

```
let dish = ("Ham", "Eggs");
Expand All @@ -3211,11 +3212,11 @@ if let ("Ham", b) = dish {

### `while let` loops

A `while let` loop is semantically identical to a `while` loop but in place of a
condition expression it expects a refutable let statement. If the value of the
expression on the right hand side of the let statement matches the pattern, the
loop body block executes and control returns to the pattern matching statement.
Otherwise, the while expression completes.
A `while let` loop is semantically identical to a `while` loop but in place of
a condition expression it expects `let` statement with a refutable pattern. If
the value of the expression on the right hand side of the `let` statement
matches the pattern, the loop body block executes and control returns to the
pattern matching statement. Otherwise, the while expression completes.

### `return` expressions

Expand Down