chore: fixup

Signed-off-by: moul <[email protected]>

examples/gno.land/p/demo/avl/pager/pager.gno

@@ -7,30 +7,55 @@ import (
 
 // NewPager creates a new Pager with default values.
 func NewPager(tree avl.ITree, defaultPageSize int, reversed bool) *pageable.Pager {
-	wrappedTree := NewAVLWrapper(tree)
+	wrappedTree := NewWrapper(tree)
 	return pageable.NewPager(wrappedTree, defaultPageSize, reversed)
 }
 
-// AVLWrapper adapts an avl.ITree to implement Pageable
-type AVLWrapper struct {
+// Wrapper adapts an avl.ITree to implement Pageable
+type Wrapper struct {
 	tree avl.ITree
 }
 
-func NewAVLWrapper(tree avl.ITree) *AVLWrapper {
-	return &AVLWrapper{tree: tree}
+func NewWrapper(tree avl.ITree) *Wrapper {
+	return &Wrapper{tree: tree}
 }
 
-func (w *AVLWrapper) Size() int {
+func (w *Wrapper) Size() int {
 	return w.tree.Size()
 }
 
-func (w *AVLWrapper) IterateByOffset(offset int, count int, cb func(index interface{}, value interface{}) bool) bool {
-	if count < 0 {
-		return w.tree.ReverseIterateByOffset(offset, count, func(key string, value interface{}) bool {
-			return cb(key, value)
-		})
+func (w *Wrapper) IterateByOffset(offset int, count int, cb func(index interface{}, value interface{}) bool) bool {
+	if count == 0 {
+		return false
 	}
+
+	size := w.tree.Size()
+	if size == 0 {
+		return false
+	}
+
+	if offset >= size {
+		return false
+	}
+
+	// Use the tree's IterateByOffset with the full count
+	// (positive for forward, negative for reverse)
 	return w.tree.IterateByOffset(offset, count, func(key string, value interface{}) bool {
 		return cb(key, value)
 	})
 }
+
+// Helper functions
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}

examples/gno.land/p/demo/avl/pager/z_filetest.gno

@@ -23,7 +23,7 @@ func main() {
 
 		println(ufmt.Sprintf("## Page %d of %d", page.PageNumber, page.TotalPages))
 		for idx, item := range page.Items {
-			println(ufmt.Sprintf("- idx=%d key=%s value=%d", idx, item.Key, item.Value))
+			println(ufmt.Sprintf("- idx=%d index=%s value=%d", idx, item.Index, item.Value))
 		}
 		println(page.Picker())
 		println()
@@ -38,63 +38,63 @@ func main() {
 // _0_ | [1](?page=1) | [2](?page=2) | … | [6](?page=6)
 //
 // ## Page 1 of 6
-// - idx=0 key=0000001 value=0
-// - idx=1 key=0000002 value=1
-// - idx=2 key=0000003 value=2
-// - idx=3 key=0000004 value=3
-// - idx=4 key=0000005 value=4
-// - idx=5 key=0000006 value=5
-// - idx=6 key=0000007 value=6
+// - idx=0 index=0000001 value=0
+// - idx=1 index=0000002 value=1
+// - idx=2 index=0000003 value=2
+// - idx=3 index=0000004 value=3
+// - idx=4 index=0000005 value=4
+// - idx=5 index=0000006 value=5
+// - idx=6 index=0000007 value=6
 // **1** | [2](?page=2) | [3](?page=3) | … | [6](?page=6)
 //
 // ## Page 2 of 6
-// - idx=0 key=0000008 value=7
-// - idx=1 key=0000009 value=8
-// - idx=2 key=000000a value=9
-// - idx=3 key=000000b value=10
-// - idx=4 key=000000c value=11
-// - idx=5 key=000000d value=12
-// - idx=6 key=000000e value=13
+// - idx=0 index=0000008 value=7
+// - idx=1 index=0000009 value=8
+// - idx=2 index=000000a value=9
+// - idx=3 index=000000b value=10
+// - idx=4 index=000000c value=11
+// - idx=5 index=000000d value=12
+// - idx=6 index=000000e value=13
 // [1](?page=1) | **2** | [3](?page=3) | [4](?page=4) | … | [6](?page=6)
 //
 // ## Page 3 of 6
-// - idx=0 key=000000f value=14
-// - idx=1 key=000000g value=15
-// - idx=2 key=000000h value=16
-// - idx=3 key=000000j value=17
-// - idx=4 key=000000k value=18
-// - idx=5 key=000000m value=19
-// - idx=6 key=000000n value=20
+// - idx=0 index=000000f value=14
+// - idx=1 index=000000g value=15
+// - idx=2 index=000000h value=16
+// - idx=3 index=000000j value=17
+// - idx=4 index=000000k value=18
+// - idx=5 index=000000m value=19
+// - idx=6 index=000000n value=20
 // [1](?page=1) | [2](?page=2) | **3** | [4](?page=4) | [5](?page=5) | [6](?page=6)
 //
 // ## Page 4 of 6
-// - idx=0 key=000000p value=21
-// - idx=1 key=000000q value=22
-// - idx=2 key=000000r value=23
-// - idx=3 key=000000s value=24
-// - idx=4 key=000000t value=25
-// - idx=5 key=000000v value=26
-// - idx=6 key=000000w value=27
+// - idx=0 index=000000p value=21
+// - idx=1 index=000000q value=22
+// - idx=2 index=000000r value=23
+// - idx=3 index=000000s value=24
+// - idx=4 index=000000t value=25
+// - idx=5 index=000000v value=26
+// - idx=6 index=000000w value=27
 // [1](?page=1) | [2](?page=2) | [3](?page=3) | **4** | [5](?page=5) | [6](?page=6)
 //
 // ## Page 5 of 6
-// - idx=0 key=000000x value=28
-// - idx=1 key=000000y value=29
-// - idx=2 key=000000z value=30
-// - idx=3 key=0000010 value=31
-// - idx=4 key=0000011 value=32
-// - idx=5 key=0000012 value=33
-// - idx=6 key=0000013 value=34
+// - idx=0 index=000000x value=28
+// - idx=1 index=000000y value=29
+// - idx=2 index=000000z value=30
+// - idx=3 index=0000010 value=31
+// - idx=4 index=0000011 value=32
+// - idx=5 index=0000012 value=33
+// - idx=6 index=0000013 value=34
 // [1](?page=1) | … | [3](?page=3) | [4](?page=4) | **5** | [6](?page=6)
 //
 // ## Page 6 of 6
-// - idx=0 key=0000014 value=35
-// - idx=1 key=0000015 value=36
-// - idx=2 key=0000016 value=37
-// - idx=3 key=0000017 value=38
-// - idx=4 key=0000018 value=39
-// - idx=5 key=0000019 value=40
-// - idx=6 key=000001a value=41
+// - idx=0 index=0000014 value=35
+// - idx=1 index=0000015 value=36
+// - idx=2 index=0000016 value=37
+// - idx=3 index=0000017 value=38
+// - idx=4 index=0000018 value=39
+// - idx=5 index=0000019 value=40
+// - idx=6 index=000001a value=41
 // [1](?page=1) | … | [4](?page=4) | [5](?page=5) | **6**
 //
 // ## Page 7 of 6

examples/gno.land/p/moul/pageable/pageable.gno

@@ -1,4 +1,15 @@
-// Package pageable provides a generic pagination system
+// Package pageable implements a flexible pagination system that can be used with any data structure
+// that implements the Pageable interface. It provides functionality for:
+//
+//   - Paginating through collections of items
+//   - Configurable page sizes
+//   - Forward and reverse iteration
+//   - URL query parameter parsing
+//   - Markdown-based pagination UI
+//
+// This package is currently used by:
+//   - gno.land/p/demo/avl/pager: implementation for AVL trees.
+//   - gno.land/p/moul/ulist/pager: implementation for ulist
 package pageable
 
 import (
@@ -9,13 +20,26 @@ import (
 	"gno.land/p/demo/ufmt"
 )
 
-// Pageable defines the minimal interface required for pagination
+// Pageable defines the minimal interface required for pagination.
+// This interface is intentionally lightweight, requiring only two methods.
+// While some data structures (like AVL trees) might have separate methods for forward
+// and reverse iteration, this interface consolidates both directions into a single
+// IterateByOffset method. It's the responsibility of the implementing wrapper to
+// handle the direction logic internally based on the offset and count parameters.
 type Pageable interface {
 	// Size returns the total number of items
 	Size() int
 
-	// IterateByOffset performs iteration starting from offset for count elements
-	// The callback receives an index and a value, returns true to stop iteration
+	// IterateByOffset performs iteration starting from offset for count elements.
+	// The callback receives an index and a value, returns true to stop iteration.
+	//
+	// For reverse iteration, the implementation should handle the direction internally
+	// by adjusting how it interprets the offset and count parameters. For example:
+	// - In forward mode: offset 0, count 5 would return items [0,1,2,3,4]
+	// - In reverse mode: offset 0, count 5 would return items [4,3,2,1,0]
+	//
+	// This approach allows the interface to remain simple while supporting
+	// bidirectional iteration through the implementation layer.
 	IterateByOffset(offset int, count int, cb func(index interface{}, value interface{}) bool) bool
 }
 
@@ -120,23 +144,12 @@ func (p *Pager) GetPageWithSize(pageNumber, pageSize int) *Page {
 	// Collect items for the current page
 	var items []Item
 	if p.Reversed {
-		// For reversed order, iterate from the end of the array
-		if offset == 0 && iterCount == 1 {
-			// Special case for last partial page
-			p.Source.IterateByOffset(0, 1, func(index interface{}, value interface{}) bool {
-				items = append(items, Item{Index: index, Value: value})
-				return true
-			})
-		} else {
-			startIndex := page.TotalItems - offset - 1
-			endIndex := startIndex - iterCount + 1
-			for i := startIndex; i >= endIndex && i >= 0; i-- {
-				p.Source.IterateByOffset(i, 1, func(index interface{}, value interface{}) bool {
-					items = append(items, Item{Index: index, Value: value})
-					return true
-				})
-			}
-		}
+		// For reversed order, use negative count to indicate reverse iteration
+		offset = page.TotalItems - offset - iterCount
+		p.Source.IterateByOffset(offset, -iterCount, func(index interface{}, value interface{}) bool {
+			items = append(items, Item{Index: index, Value: value})
+			return false
+		})
 	} else {
 		p.Source.IterateByOffset(offset, iterCount, func(index interface{}, value interface{}) bool {
 			items = append(items, Item{Index: index, Value: value})

examples/gno.land/p/moul/pageable/pageable_test.gno

@@ -136,7 +136,7 @@ func TestReversedPager(t *testing.T) {
 	}
 
 	// Check if items are in reverse order
-	if page.Items[0].Value.(int) != 2 || page.Items[1].Value.(int) != 1 {
+	if page.Items[0].Value.(int) != 5 || page.Items[1].Value.(int) != 4 {
 		t.Errorf("items not in reverse order: got %v", page.Items)
 	}
 }