README
¶
pqs 
A minimal, generic priority queue in Go using ordered types.
The pqs package provides the simplest form of a priority queue for values that are inherently comparable (e.g., int, float64, string). It does not support key-based lookups or custom structures — items are their own priority.
✨ Features
- ✅ Minimal: single-type input, no struct wrapping
- ✅ Generic: works with any
cmp.Orderedtype - ✅ Custom comparator: control min/max or custom logic
- ❌ No stability guarantees (insertion order not preserved for equal priority)
- ❌ No key support or item updates
🧱 Example
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
q := pqs.New(pqs.MinFirst[int])
pqs.Enqueue(q, 3)
pqs.Enqueue(q, 1)
pqs.Enqueue(q, 2)
for pqs.Len(q) > 0 {
item, _ := pqs.Dequeue(q)
fmt.Println(item)
}
}
// Output:
// 1
// 2
// 3
📚 Use When
- You need a fast, generic min/max heap
- The item itself is the priority
- You don’t need key lookups, updates, or custom types
🚫 Avoid If
- You need to update item priority (
kmpqs,kpqs) - You need key-based identity (
kpqs,kmpqs) - You want stable ordering among equal-priority items (
mpqs,kpqs)
🔍 Alternatives
| Package | Use case |
|---|---|
mpqs |
custom structs with external priority |
kpqs |
key + internal priority field |
kmpqs |
key + external priority control |
Documentation
¶
Overview ¶
Example (StringLengthPriority) ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
lengthPriority := func(x, y string) bool {
return len(x) < len(y)
}
pq := pqs.New(lengthPriority)
pqs.Enqueue(pq, "apple")
pqs.Enqueue(pq, "kiwi")
pqs.Enqueue(pq, "banana")
for pqs.Len(pq) > 0 {
item, _ := pqs.Dequeue(pq)
fmt.Println(item)
}
}
Output: kiwi apple banana
Index ¶
- func Clear[T cmp.Ordered](pq *PriorityQueue[T])
- func Dequeue[T cmp.Ordered](pq *PriorityQueue[T]) (T, bool)
- func Enqueue[T cmp.Ordered](pq *PriorityQueue[T], item T)
- func Len[T cmp.Ordered](pq *PriorityQueue[T]) int
- func MaxFirst[T cmp.Ordered](x, y T) bool
- func MinFirst[T cmp.Ordered](x, y T) bool
- func Peek[T cmp.Ordered](pq *PriorityQueue[T]) (T, bool)
- type PriorityQueue
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Clear ¶
func Clear[T cmp.Ordered](pq *PriorityQueue[T])
Example ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
pq := pqs.New(pqs.MinFirst[int])
pqs.Enqueue(pq, 1)
pqs.Clear(pq)
fmt.Println(pqs.Len(pq))
}
Output: 0
func Dequeue ¶
func Dequeue[T cmp.Ordered](pq *PriorityQueue[T]) (T, bool)
Example ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
pq := pqs.New(pqs.MinFirst[int])
pqs.Enqueue(pq, 2)
pqs.Enqueue(pq, 1)
item, _ := pqs.Dequeue(pq)
fmt.Println(item)
}
Output: 1
func Enqueue ¶
func Enqueue[T cmp.Ordered](pq *PriorityQueue[T], item T)
Example ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
pq := pqs.New(pqs.MinFirst[int])
pqs.Enqueue(pq, 5)
item, _ := pqs.Peek(pq)
fmt.Println(item)
}
Output: 5
func Len ¶
func Len[T cmp.Ordered](pq *PriorityQueue[T]) int
Example ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
pq := pqs.New(pqs.MinFirst[int])
fmt.Println(pqs.Len(pq))
pqs.Enqueue(pq, 1)
fmt.Println(pqs.Len(pq))
}
Output: 0 1
func MaxFirst ¶
Example ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
fmt.Println(pqs.MaxFirst(1, 2))
}
Output: false
Types ¶
type PriorityQueue ¶
func New ¶
func New[T cmp.Ordered]( lessFunc func(x, y T) bool, ) *PriorityQueue[T]
Example ¶
package main
import (
"fmt"
"github.com/byExist/priorityqueues/pqs"
)
func main() {
pq := pqs.New(pqs.MinFirst[int])
pqs.Enqueue(pq, 3)
pqs.Enqueue(pq, 1)
item, _ := pqs.Dequeue(pq)
fmt.Println(item)
}
Output: 1
Source Files
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