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Add a rudimentary vector container to ameliorate the inability to allocate dynamic arrays.
SVN=114931
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132
src/lib/container/vector.go
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132
src/lib/container/vector.go
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package vector
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export Vector, New;
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/*
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import vector "vector"
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v := vector.New();
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v.Insert(0, new(Foo));
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v.Append(new(Foo));
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v.Delete(0);
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for i := 0; i < v.Len(); i++ { f(v.At(i)); }
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*/
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type Element interface {
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}
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type Vector struct {
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nalloc int;
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nelem int;
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elem *[]Element;
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}
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// BUG: workaround for non-constant allocation.
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// i must be a power of 10.
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func Alloc(i int) *[]Element {
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print "Alloc ", i, "\n";
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switch i {
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case 1:
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return new([1]Element);
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case 10:
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return new([10]Element);
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case 100:
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return new([100]Element);
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case 1000:
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return new([1000]Element);
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}
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print "bad size ", i, "\n";
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panic "not known size\n";
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}
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func is_pow10(i int) bool {
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switch i {
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case 1, 10, 100, 1000:
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return true;
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}
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return false;
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}
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func New() *Vector {
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v := new(Vector);
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v.nelem = 0;
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v.nalloc = 1;
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v.elem = Alloc(v.nalloc);
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return v;
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}
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func (v *Vector) Len() int {
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return v.nelem;
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}
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func (v *Vector) At(i int) Element {
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if i < 0 || i >= v.nelem {
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//return nil; // BUG
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panic "At out of range\n";
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}
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return v.elem[i];
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}
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func (v *Vector) Delete(i int) {
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if i < 0 || i >= v.nelem {
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panic "Delete out of range\n";
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}
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for j := i+1; j < v.nelem; j++ {
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v.elem[j-1] = v.elem[j];
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}
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v.nelem--;
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v.elem[v.nelem] = nil;
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}
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func (v *Vector) Insert(i int, e Element) {
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if i > v.nelem {
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panic "Del too large\n";
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}
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if v.nelem == v.nalloc && is_pow10(v.nalloc) {
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n := Alloc(v.nalloc * 10);
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for j := 0; j < v.nalloc; j++ {
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n[j] = v.elem[j];
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}
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v.elem = n;
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v.nalloc *= 10;
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}
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// make a hole
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for j := v.nelem; j > i; j-- {
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v.elem[j] = v.elem[j-1];
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}
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v.elem[i] = e;
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v.nelem++;
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}
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func (v *Vector) Append(e Element) {
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v.Insert(v.nelem, e);
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}
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/*
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type I struct { val int; }; // BUG: can't be local;
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func Test() {
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i0 := new(I); i0.val = 0;
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i1 := new(I); i1.val = 11;
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i2 := new(I); i2.val = 222;
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i3 := new(I); i3.val = 3333;
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i4 := new(I); i4.val = 44444;
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v := New();
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print "hi\n";
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v.Insert(0, i4);
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v.Insert(0, i3);
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v.Insert(0, i2);
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v.Insert(0, i1);
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v.Insert(0, i0);
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for i := 0; i < v.Len(); i++ {
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var x *I;
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x = v.At(i);
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print i, " ", x.val, "\n"; // BUG: can't use I(v.At(i))
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}
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}
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export Test;
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*/
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