diff options
Diffstat (limited to 'libgo/go/html/template/clone.go')
-rw-r--r-- | libgo/go/html/template/clone.go | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/libgo/go/html/template/clone.go b/libgo/go/html/template/clone.go new file mode 100644 index 0000000..d0d8ea4 --- /dev/null +++ b/libgo/go/html/template/clone.go @@ -0,0 +1,90 @@ +// Copyright 2011 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. + +package template + +import ( + "text/template/parse" +) + +// clone clones a template Node. +func clone(n parse.Node) parse.Node { + switch t := n.(type) { + case *parse.ActionNode: + return cloneAction(t) + case *parse.IfNode: + b := new(parse.IfNode) + copyBranch(&b.BranchNode, &t.BranchNode) + return b + case *parse.ListNode: + return cloneList(t) + case *parse.RangeNode: + b := new(parse.RangeNode) + copyBranch(&b.BranchNode, &t.BranchNode) + return b + case *parse.TemplateNode: + return cloneTemplate(t) + case *parse.TextNode: + return cloneText(t) + case *parse.WithNode: + b := new(parse.WithNode) + copyBranch(&b.BranchNode, &t.BranchNode) + return b + } + panic("cloning " + n.String() + " is unimplemented") +} + +// cloneAction returns a deep clone of n. +func cloneAction(n *parse.ActionNode) *parse.ActionNode { + // We use keyless fields because they won't compile if a field is added. + return &parse.ActionNode{n.NodeType, n.Line, clonePipe(n.Pipe)} +} + +// cloneList returns a deep clone of n. +func cloneList(n *parse.ListNode) *parse.ListNode { + if n == nil { + return nil + } + // We use keyless fields because they won't compile if a field is added. + c := parse.ListNode{n.NodeType, make([]parse.Node, len(n.Nodes))} + for i, child := range n.Nodes { + c.Nodes[i] = clone(child) + } + return &c +} + +// clonePipe returns a shallow clone of n. +// The escaper does not modify pipe descendants in place so there's no need to +// clone deeply. +func clonePipe(n *parse.PipeNode) *parse.PipeNode { + if n == nil { + return nil + } + // We use keyless fields because they won't compile if a field is added. + return &parse.PipeNode{n.NodeType, n.Line, n.Decl, n.Cmds} +} + +// cloneTemplate returns a deep clone of n. +func cloneTemplate(n *parse.TemplateNode) *parse.TemplateNode { + // We use keyless fields because they won't compile if a field is added. + return &parse.TemplateNode{n.NodeType, n.Line, n.Name, clonePipe(n.Pipe)} +} + +// cloneText clones the given node sharing its []byte. +func cloneText(n *parse.TextNode) *parse.TextNode { + // We use keyless fields because they won't compile if a field is added. + return &parse.TextNode{n.NodeType, n.Text} +} + +// copyBranch clones src into dst. +func copyBranch(dst, src *parse.BranchNode) { + // We use keyless fields because they won't compile if a field is added. + *dst = parse.BranchNode{ + src.NodeType, + src.Line, + clonePipe(src.Pipe), + cloneList(src.List), + cloneList(src.ElseList), + } +} |