Comments and style for rope

buffer.go

@@ -20,7 +20,7 @@ type Buffer struct {
 	// This is the text stored everytime the buffer is saved to check if the buffer is modified
 	savedText string
 
-	// Provide efficient and easy access to text and lines so the rope toString does not
+	// Provide efficient and easy access to text and lines so the rope String does not
 	// need to be constantly recalculated
 	// These variables are updated in the update() function
 	text  string
@@ -30,7 +30,7 @@ type Buffer struct {
 // NewBuffer creates a new buffer from `txt` with path and name `path`
 func NewBuffer(txt, path string) *Buffer {
 	b := new(Buffer)
-	b.r = newRope(txt)
+	b.r = NewRope(txt)
 	b.path = path
 	b.name = path
 	b.savedText = txt
@@ -42,7 +42,7 @@ func NewBuffer(txt, path string) *Buffer {
 
 // Update fetches the string from the rope and updates the `text` and `lines` in the buffer
 func (b *Buffer) Update() {
-	b.text = b.r.toString()
+	b.text = b.r.String()
 	b.lines = strings.Split(b.text, "\n")
 }
 
@@ -60,13 +60,13 @@ func (b *Buffer) SaveAs(filename string) error {
 
 // Insert a string into the rope
 func (b *Buffer) Insert(idx int, value string) {
-	b.r.insert(idx, value)
+	b.r.Insert(idx, value)
 	b.Update()
 }
 
 // Remove a slice of the rope from start to end (exclusive)
 func (b *Buffer) Remove(start, end int) {
-	b.r.remove(start, end)
+	b.r.Remove(start, end)
 	b.Update()
 }
 

rope.go

@@ -1,31 +1,35 @@
 package main
 
 import (
-	// "fmt"
 	"math"
 	"unicode/utf8"
 )
 
 const (
-	ropeSplitLength    = 1000
+	// RopeSplitLength defines how large can a string be before it is split into two nodes
-	ropeJoinLength     = 500
+	RopeSplitLength = 1000
-	ropeRebalanceRatio = 1.2
+	// RopeJoinLength defines how short can a string be before it is joined
+	RopeJoinLength = 500
+	// RopeRebalanceRatio = 1.2
 )
 
-func min(a, b int) int {
+// Min takes the min of two ints
+func Min(a, b int) int {
 	if a > b {
 		return b
 	}
 	return a
 }
 
-func max(a, b int) int {
+// Max takes the max of two ints
+func Max(a, b int) int {
 	if a > b {
 		return a
 	}
 	return b
 }
 
+// A Rope is a data structure for efficiently manipulating large strings
 type Rope struct {
 	left     *Rope
 	right    *Rope
@@ -35,28 +39,30 @@ type Rope struct {
 	len int
 }
 
-func newRope(str string) *Rope {
+// NewRope returns a new rope from a given string
+func NewRope(str string) *Rope {
 	r := new(Rope)
 	r.value = str
 	r.valueNil = false
 	r.len = utf8.RuneCountInString(r.value)
 
-	r.adjust()
+	r.Adjust()
 
 	return r
 }
 
-func (r *Rope) adjust() {
+// Adjust modifies the rope so it is more balanced
+func (r *Rope) Adjust() {
 	if !r.valueNil {
-		if r.len > ropeSplitLength {
+		if r.len > RopeSplitLength {
 			divide := int(math.Floor(float64(r.len) / 2))
-			r.left = newRope(r.value[:divide])
+			r.left = NewRope(r.value[:divide])
-			r.right = newRope(r.value[divide:])
+			r.right = NewRope(r.value[divide:])
 			r.valueNil = true
 		}
 	} else {
-		if r.len < ropeJoinLength {
+		if r.len < RopeJoinLength {
-			r.value = r.left.toString() + r.right.toString()
+			r.value = r.left.String() + r.right.String()
 			r.valueNil = false
 			r.left = nil
 			r.right = nil
@@ -64,36 +70,39 @@ func (r *Rope) adjust() {
 	}
 }
 
-func (r *Rope) toString() string {
+// String returns the string representation of the rope
+func (r *Rope) String() string {
 	if !r.valueNil {
 		return r.value
 	}
-	return r.left.toString() + r.right.toString()
+	return r.left.String() + r.right.String()
 }
 
-func (r *Rope) remove(start, end int) {
+// Remove deletes a slice of the rope from start the to end (exclusive)
+func (r *Rope) Remove(start, end int) {
 	if !r.valueNil {
 		r.value = string(append([]rune(r.value)[:start], []rune(r.value)[end:]...))
 		r.valueNil = false
 		r.len = utf8.RuneCountInString(r.value)
 	} else {
-		leftStart := min(start, r.left.len)
+		leftStart := Min(start, r.left.len)
-		leftEnd := min(end, r.left.len)
+		leftEnd := Min(end, r.left.len)
-		rightStart := max(0, min(start-r.left.len, r.right.len))
+		rightStart := Max(0, Min(start-r.left.len, r.right.len))
-		rightEnd := max(0, min(end-r.left.len, r.right.len))
+		rightEnd := Max(0, Min(end-r.left.len, r.right.len))
 		if leftStart < r.left.len {
-			r.left.remove(leftStart, leftEnd)
+			r.left.Remove(leftStart, leftEnd)
 		}
 		if rightEnd > 0 {
-			r.right.remove(rightStart, rightEnd)
+			r.right.Remove(rightStart, rightEnd)
 		}
 		r.len = r.left.len + r.right.len
 	}
 
-	r.adjust()
+	r.Adjust()
 }
 
-func (r *Rope) insert(pos int, value string) {
+// Insert inserts a string into the rope at a specified position
+func (r *Rope) Insert(pos int, value string) {
 	if !r.valueNil {
 		first := append([]rune(r.value)[:pos], []rune(value)...)
 		r.value = string(append(first, []rune(r.value)[pos:]...))
@@ -101,12 +110,12 @@ func (r *Rope) insert(pos int, value string) {
 		r.len = utf8.RuneCountInString(r.value)
 	} else {
 		if pos < r.left.len {
-			r.left.insert(pos, value)
+			r.left.Insert(pos, value)
 			r.len = r.left.len + r.right.len
 		} else {
-			r.right.insert(pos-r.left.len, value)
+			r.right.Insert(pos-r.left.len, value)
 		}
 	}
 
-	r.adjust()
+	r.Adjust()
 }