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// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// CAUTION: If this file is not vector.go, it was generated
// automatically from vector.go - DO NOT EDIT in that case!
package vector
func (p *Vector) realloc(length, capacity int) (b []interface{}) {
if capacity < initialSize {
capacity = initialSize
}
if capacity < length {
capacity = length
}
b = make(Vector, length, capacity)
copy(b, *p)
*p = b
return
}
// Insert n elements at position i.
func (p *Vector) Expand(i, n int) {
a := *p
// make sure we have enough space
len0 := len(a)
len1 := len0 + n
if len1 <= cap(a) {
// enough space - just expand
a = a[0:len1]
} else {
// not enough space - double capacity
capb := cap(a) * 2
if capb < len1 {
// still not enough - use required length
capb = len1
}
// capb >= len1
a = p.realloc(len1, capb)
}
// make a hole
for j := len0 - 1; j >= i; j-- {
a[j+n] = a[j]
}
*p = a
}
// Insert n elements at the end of a vector.
func (p *Vector) Extend(n int) { p.Expand(len(*p), n) }
// Resize changes the length and capacity of a vector.
// If the new length is shorter than the current length, Resize discards
// trailing elements. If the new length is longer than the current length,
// Resize adds the respective zero values for the additional elements. The capacity
// parameter is ignored unless the new length or capacity is longer than the current
// capacity. The resized vector's capacity may be larger than the requested capacity.
func (p *Vector) Resize(length, capacity int) *Vector {
a := *p
if length > cap(a) || capacity > cap(a) {
// not enough space or larger capacity requested explicitly
a = p.realloc(length, capacity)
} else if length < len(a) {
// clear trailing elements
for i := range a[length:] {
var zero interface{}
a[length+i] = zero
}
}
*p = a[0:length]
return p
}
// Len returns the number of elements in the vector.
// Same as len(*p).
func (p *Vector) Len() int { return len(*p) }
// Cap returns the capacity of the vector; that is, the
// maximum length the vector can grow without resizing.
// Same as cap(*p).
func (p *Vector) Cap() int { return cap(*p) }
// At returns the i'th element of the vector.
func (p *Vector) At(i int) interface{} { return (*p)[i] }
// Set sets the i'th element of the vector to value x.
func (p *Vector) Set(i int, x interface{}) { (*p)[i] = x }
// Last returns the element in the vector of highest index.
func (p *Vector) Last() interface{} { return (*p)[len(*p)-1] }
// Copy makes a copy of the vector and returns it.
func (p *Vector) Copy() Vector {
arr := make(Vector, len(*p))
copy(arr, *p)
return arr
}
// Insert inserts into the vector an element of value x before
// the current element at index i.
func (p *Vector) Insert(i int, x interface{}) {
p.Expand(i, 1)
(*p)[i] = x
}
// Delete deletes the i'th element of the vector. The gap is closed so the old
// element at index i+1 has index i afterwards.
func (p *Vector) Delete(i int) {
a := *p
n := len(a)
copy(a[i:n-1], a[i+1:n])
var zero interface{}
a[n-1] = zero // support GC, zero out entry
*p = a[0 : n-1]
}
// InsertVector inserts into the vector the contents of the vector
// x such that the 0th element of x appears at index i after insertion.
func (p *Vector) InsertVector(i int, x *Vector) {
b := *x
p.Expand(i, len(b))
copy((*p)[i:i+len(b)], b)
}
// Cut deletes elements i through j-1, inclusive.
func (p *Vector) Cut(i, j int) {
a := *p
n := len(a)
m := n - (j - i)
copy(a[i:m], a[j:n])
for k := m; k < n; k++ { //TODO(bflm) don't zero out the elements unless it's a Vector.
var zero interface{}
a[k] = zero // support GC, zero out entries
}
*p = a[0:m]
}
// Slice returns a new sub-vector by slicing the old one to extract slice [i:j].
// The elements are copied. The original vector is unchanged.
func (p *Vector) Slice(i, j int) *Vector {
var s Vector
s.realloc(j-i, 0) // will fail in Init() if j < i
copy(s, (*p)[i:j])
return &s
}
// Convenience wrappers
// Push appends x to the end of the vector.
func (p *Vector) Push(x interface{}) { p.Insert(len(*p), x) }
// Pop deletes the last element of the vector.
func (p *Vector) Pop() interface{} {
a := *p
i := len(a) - 1
x := a[i]
var zero interface{}
a[i] = zero // support GC, zero out entry
*p = a[0:i]
return x
}
// AppendVector appends the entire vector x to the end of this vector.
func (p *Vector) AppendVector(x *Vector) { p.InsertVector(len(*p), x) }
// Swap exchanges the elements at indexes i and j.
func (p *Vector) Swap(i, j int) {
a := *p
a[i], a[j] = a[j], a[i]
}
// Do calls function f for each element of the vector, in order.
// The behavior of Do is undefined if f changes *p.
func (p *Vector) Do(f func(elem interface{})) {
for _, e := range *p {
f(e)
}
}
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