Range expressions
Syntax
RangeExpression :
RangeExpr
| RangeFromExpr
| RangeToExpr
| RangeFullExpr
| RangeInclusiveExpr
| RangeToInclusiveExprRangeExpr :
Expression..ExpressionRangeFromExpr :
Expression..RangeToExpr :
..ExpressionRangeFullExpr :
..RangeExpr :
Expression..=ExpressionRangeToExpr :
..=Expression
The .. and ..= operators will construct an object of one of the
std::ops::Range (or core::ops::Range) variants, according to the following
table:
| Production | Syntax | Type | Range |
|---|---|---|---|
| RangeExpr | start..end | std::ops::Range | start ≤ x < end |
| RangeFromExpr | start.. | std::ops::RangeFrom | start ≤ x |
| RangeToExpr | ..end | std::ops::RangeTo | x < end |
| RangeFullExpr | .. | std::ops::RangeFull | - |
| RangeInclusiveExpr | start..=end | std::ops::RangeInclusive | start ≤ x ≤ end |
| RangeToInclusiveExpr | ..=end | std::ops::RangeToInclusive | x ≤ end |
Examples:
# #![allow(unused_variables)] #fn main() { 1..2; // std::ops::Range 3..; // std::ops::RangeFrom ..4; // std::ops::RangeTo ..; // std::ops::RangeFull 5..=6; // std::ops::RangeInclusive ..=7; // std::ops::RangeToInclusive #}
The following expressions are equivalent.
# #![allow(unused_variables)] #fn main() { let x = std::ops::Range {start: 0, end: 10}; let y = 0..10; assert_eq!(x, y); #}
Ranges can be used in for loops:
# #![allow(unused_variables)] #fn main() { for i in 1..11 { println!("{}", i); } #}