Index a priority queue by name

Priority queues intentionally expose only name-based read indexing.

Usage

# S3 method for class 'priority_queue'
x[i, ...]

# S3 method for class 'priority_queue'
x[[i, ...]]

# S3 method for class 'priority_queue'
x[i] <- value

# S3 method for class 'priority_queue'
x[[i]] <- value

Arguments

x

A `priority_queue`.

i

For `[`, character names.

...

Unused.

value

Replacement value (unsupported).

Value

For `[`, a `priority_queue` containing matched named entries.

For `[[`, one payload element matched by a single character name.

No return value; always errors because replacement indexing is unsupported.

No return value; always errors because replacement indexing is unsupported.

Details

For `[`: - `i` must be character (one or more names).

For `[[`: - `i` must be a single character name.

Numeric/logical indexing and replacement indexing are unsupported for `priority_queue`. Cast with [as_flexseq()] for full sequence-style indexing.

See also

[\[.flexseq], [as_flexseq()]

Examples

q <- as_priority_queue(c("A", "B"), priorities = c(2, 1), names = c("a", "b"))
q["a"]
#> <priority_queue> size=1
#> min_priority=2 max_priority=2
q[["b"]]
#> [1] "B"
try(q[[1]])
#> Error in `[[.priority_queue`(q, 1) : 
#>   `[[.priority_queue` supports scalar character names only. Cast first with `as_flexseq()`.