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-rw-r--r--src/pkg/text/template/parse/node.go608
1 files changed, 608 insertions, 0 deletions
diff --git a/src/pkg/text/template/parse/node.go b/src/pkg/text/template/parse/node.go
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+++ b/src/pkg/text/template/parse/node.go
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+// 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.
+
+// Parse nodes.
+
+package parse
+
+import (
+ "bytes"
+ "fmt"
+ "strconv"
+ "strings"
+)
+
+// A node is an element in the parse tree. The interface is trivial.
+type Node interface {
+ Type() NodeType
+ String() string
+ // Copy does a deep copy of the Node and all its components.
+ // To avoid type assertions, some XxxNodes also have specialized
+ // CopyXxx methods that return *XxxNode.
+ Copy() Node
+}
+
+// NodeType identifies the type of a parse tree node.
+type NodeType int
+
+// Type returns itself and provides an easy default implementation
+// for embedding in a Node. Embedded in all non-trivial Nodes.
+func (t NodeType) Type() NodeType {
+ return t
+}
+
+const (
+ NodeText NodeType = iota // Plain text.
+ NodeAction // A simple action such as field evaluation.
+ NodeBool // A boolean constant.
+ NodeCommand // An element of a pipeline.
+ NodeDot // The cursor, dot.
+ nodeElse // An else action. Not added to tree.
+ nodeEnd // An end action. Not added to tree.
+ NodeField // A field or method name.
+ NodeIdentifier // An identifier; always a function name.
+ NodeIf // An if action.
+ NodeList // A list of Nodes.
+ NodeNumber // A numerical constant.
+ NodePipe // A pipeline of commands.
+ NodeRange // A range action.
+ NodeString // A string constant.
+ NodeTemplate // A template invocation action.
+ NodeVariable // A $ variable.
+ NodeWith // A with action.
+)
+
+// Nodes.
+
+// ListNode holds a sequence of nodes.
+type ListNode struct {
+ NodeType
+ Nodes []Node // The element nodes in lexical order.
+}
+
+func newList() *ListNode {
+ return &ListNode{NodeType: NodeList}
+}
+
+func (l *ListNode) append(n Node) {
+ l.Nodes = append(l.Nodes, n)
+}
+
+func (l *ListNode) String() string {
+ b := new(bytes.Buffer)
+ for _, n := range l.Nodes {
+ fmt.Fprint(b, n)
+ }
+ return b.String()
+}
+
+func (l *ListNode) CopyList() *ListNode {
+ if l == nil {
+ return l
+ }
+ n := newList()
+ for _, elem := range l.Nodes {
+ n.append(elem.Copy())
+ }
+ return n
+}
+
+func (l *ListNode) Copy() Node {
+ return l.CopyList()
+}
+
+// TextNode holds plain text.
+type TextNode struct {
+ NodeType
+ Text []byte // The text; may span newlines.
+}
+
+func newText(text string) *TextNode {
+ return &TextNode{NodeType: NodeText, Text: []byte(text)}
+}
+
+func (t *TextNode) String() string {
+ return fmt.Sprintf("%q", t.Text)
+}
+
+func (t *TextNode) Copy() Node {
+ return &TextNode{NodeType: NodeText, Text: append([]byte{}, t.Text...)}
+}
+
+// PipeNode holds a pipeline with optional declaration
+type PipeNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Decl []*VariableNode // Variable declarations in lexical order.
+ Cmds []*CommandNode // The commands in lexical order.
+}
+
+func newPipeline(line int, decl []*VariableNode) *PipeNode {
+ return &PipeNode{NodeType: NodePipe, Line: line, Decl: decl}
+}
+
+func (p *PipeNode) append(command *CommandNode) {
+ p.Cmds = append(p.Cmds, command)
+}
+
+func (p *PipeNode) String() string {
+ s := ""
+ if len(p.Decl) > 0 {
+ for i, v := range p.Decl {
+ if i > 0 {
+ s += ", "
+ }
+ s += v.String()
+ }
+ s += " := "
+ }
+ for i, c := range p.Cmds {
+ if i > 0 {
+ s += " | "
+ }
+ s += c.String()
+ }
+ return s
+}
+
+func (p *PipeNode) CopyPipe() *PipeNode {
+ if p == nil {
+ return p
+ }
+ var decl []*VariableNode
+ for _, d := range p.Decl {
+ decl = append(decl, d.Copy().(*VariableNode))
+ }
+ n := newPipeline(p.Line, decl)
+ for _, c := range p.Cmds {
+ n.append(c.Copy().(*CommandNode))
+ }
+ return n
+}
+
+func (p *PipeNode) Copy() Node {
+ return p.CopyPipe()
+}
+
+// ActionNode holds an action (something bounded by delimiters).
+// Control actions have their own nodes; ActionNode represents simple
+// ones such as field evaluations.
+type ActionNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Pipe *PipeNode // The pipeline in the action.
+}
+
+func newAction(line int, pipe *PipeNode) *ActionNode {
+ return &ActionNode{NodeType: NodeAction, Line: line, Pipe: pipe}
+}
+
+func (a *ActionNode) String() string {
+ return fmt.Sprintf("{{%s}}", a.Pipe)
+
+}
+
+func (a *ActionNode) Copy() Node {
+ return newAction(a.Line, a.Pipe.CopyPipe())
+
+}
+
+// CommandNode holds a command (a pipeline inside an evaluating action).
+type CommandNode struct {
+ NodeType
+ Args []Node // Arguments in lexical order: Identifier, field, or constant.
+}
+
+func newCommand() *CommandNode {
+ return &CommandNode{NodeType: NodeCommand}
+}
+
+func (c *CommandNode) append(arg Node) {
+ c.Args = append(c.Args, arg)
+}
+
+func (c *CommandNode) String() string {
+ s := ""
+ for i, arg := range c.Args {
+ if i > 0 {
+ s += " "
+ }
+ s += arg.String()
+ }
+ return s
+}
+
+func (c *CommandNode) Copy() Node {
+ if c == nil {
+ return c
+ }
+ n := newCommand()
+ for _, c := range c.Args {
+ n.append(c.Copy())
+ }
+ return n
+}
+
+// IdentifierNode holds an identifier.
+type IdentifierNode struct {
+ NodeType
+ Ident string // The identifier's name.
+}
+
+// NewIdentifier returns a new IdentifierNode with the given identifier name.
+func NewIdentifier(ident string) *IdentifierNode {
+ return &IdentifierNode{NodeType: NodeIdentifier, Ident: ident}
+}
+
+func (i *IdentifierNode) String() string {
+ return i.Ident
+}
+
+func (i *IdentifierNode) Copy() Node {
+ return NewIdentifier(i.Ident)
+}
+
+// VariableNode holds a list of variable names. The dollar sign is
+// part of the name.
+type VariableNode struct {
+ NodeType
+ Ident []string // Variable names in lexical order.
+}
+
+func newVariable(ident string) *VariableNode {
+ return &VariableNode{NodeType: NodeVariable, Ident: strings.Split(ident, ".")}
+}
+
+func (v *VariableNode) String() string {
+ s := ""
+ for i, id := range v.Ident {
+ if i > 0 {
+ s += "."
+ }
+ s += id
+ }
+ return s
+}
+
+func (v *VariableNode) Copy() Node {
+ return &VariableNode{NodeType: NodeVariable, Ident: append([]string{}, v.Ident...)}
+}
+
+// DotNode holds the special identifier '.'. It is represented by a nil pointer.
+type DotNode bool
+
+func newDot() *DotNode {
+ return nil
+}
+
+func (d *DotNode) Type() NodeType {
+ return NodeDot
+}
+
+func (d *DotNode) String() string {
+ return "."
+}
+
+func (d *DotNode) Copy() Node {
+ return newDot()
+}
+
+// FieldNode holds a field (identifier starting with '.').
+// The names may be chained ('.x.y').
+// The period is dropped from each ident.
+type FieldNode struct {
+ NodeType
+ Ident []string // The identifiers in lexical order.
+}
+
+func newField(ident string) *FieldNode {
+ return &FieldNode{NodeType: NodeField, Ident: strings.Split(ident[1:], ".")} // [1:] to drop leading period
+}
+
+func (f *FieldNode) String() string {
+ s := ""
+ for _, id := range f.Ident {
+ s += "." + id
+ }
+ return s
+}
+
+func (f *FieldNode) Copy() Node {
+ return &FieldNode{NodeType: NodeField, Ident: append([]string{}, f.Ident...)}
+}
+
+// BoolNode holds a boolean constant.
+type BoolNode struct {
+ NodeType
+ True bool // The value of the boolean constant.
+}
+
+func newBool(true bool) *BoolNode {
+ return &BoolNode{NodeType: NodeBool, True: true}
+}
+
+func (b *BoolNode) String() string {
+ if b.True {
+ return "true"
+ }
+ return "false"
+}
+
+func (b *BoolNode) Copy() Node {
+ return newBool(b.True)
+}
+
+// NumberNode holds a number: signed or unsigned integer, float, or complex.
+// The value is parsed and stored under all the types that can represent the value.
+// This simulates in a small amount of code the behavior of Go's ideal constants.
+type NumberNode struct {
+ NodeType
+ IsInt bool // Number has an integral value.
+ IsUint bool // Number has an unsigned integral value.
+ IsFloat bool // Number has a floating-point value.
+ IsComplex bool // Number is complex.
+ Int64 int64 // The signed integer value.
+ Uint64 uint64 // The unsigned integer value.
+ Float64 float64 // The floating-point value.
+ Complex128 complex128 // The complex value.
+ Text string // The original textual representation from the input.
+}
+
+func newNumber(text string, typ itemType) (*NumberNode, error) {
+ n := &NumberNode{NodeType: NodeNumber, Text: text}
+ switch typ {
+ case itemCharConstant:
+ rune, _, tail, err := strconv.UnquoteChar(text[1:], text[0])
+ if err != nil {
+ return nil, err
+ }
+ if tail != "'" {
+ return nil, fmt.Errorf("malformed character constant: %s", text)
+ }
+ n.Int64 = int64(rune)
+ n.IsInt = true
+ n.Uint64 = uint64(rune)
+ n.IsUint = true
+ n.Float64 = float64(rune) // odd but those are the rules.
+ n.IsFloat = true
+ return n, nil
+ case itemComplex:
+ // fmt.Sscan can parse the pair, so let it do the work.
+ if _, err := fmt.Sscan(text, &n.Complex128); err != nil {
+ return nil, err
+ }
+ n.IsComplex = true
+ n.simplifyComplex()
+ return n, nil
+ }
+ // Imaginary constants can only be complex unless they are zero.
+ if len(text) > 0 && text[len(text)-1] == 'i' {
+ f, err := strconv.ParseFloat(text[:len(text)-1], 64)
+ if err == nil {
+ n.IsComplex = true
+ n.Complex128 = complex(0, f)
+ n.simplifyComplex()
+ return n, nil
+ }
+ }
+ // Do integer test first so we get 0x123 etc.
+ u, err := strconv.ParseUint(text, 0, 64) // will fail for -0; fixed below.
+ if err == nil {
+ n.IsUint = true
+ n.Uint64 = u
+ }
+ i, err := strconv.ParseInt(text, 0, 64)
+ if err == nil {
+ n.IsInt = true
+ n.Int64 = i
+ if i == 0 {
+ n.IsUint = true // in case of -0.
+ n.Uint64 = u
+ }
+ }
+ // If an integer extraction succeeded, promote the float.
+ if n.IsInt {
+ n.IsFloat = true
+ n.Float64 = float64(n.Int64)
+ } else if n.IsUint {
+ n.IsFloat = true
+ n.Float64 = float64(n.Uint64)
+ } else {
+ f, err := strconv.ParseFloat(text, 64)
+ if err == nil {
+ n.IsFloat = true
+ n.Float64 = f
+ // If a floating-point extraction succeeded, extract the int if needed.
+ if !n.IsInt && float64(int64(f)) == f {
+ n.IsInt = true
+ n.Int64 = int64(f)
+ }
+ if !n.IsUint && float64(uint64(f)) == f {
+ n.IsUint = true
+ n.Uint64 = uint64(f)
+ }
+ }
+ }
+ if !n.IsInt && !n.IsUint && !n.IsFloat {
+ return nil, fmt.Errorf("illegal number syntax: %q", text)
+ }
+ return n, nil
+}
+
+// simplifyComplex pulls out any other types that are represented by the complex number.
+// These all require that the imaginary part be zero.
+func (n *NumberNode) simplifyComplex() {
+ n.IsFloat = imag(n.Complex128) == 0
+ if n.IsFloat {
+ n.Float64 = real(n.Complex128)
+ n.IsInt = float64(int64(n.Float64)) == n.Float64
+ if n.IsInt {
+ n.Int64 = int64(n.Float64)
+ }
+ n.IsUint = float64(uint64(n.Float64)) == n.Float64
+ if n.IsUint {
+ n.Uint64 = uint64(n.Float64)
+ }
+ }
+}
+
+func (n *NumberNode) String() string {
+ return n.Text
+}
+
+func (n *NumberNode) Copy() Node {
+ nn := new(NumberNode)
+ *nn = *n // Easy, fast, correct.
+ return nn
+}
+
+// StringNode holds a string constant. The value has been "unquoted".
+type StringNode struct {
+ NodeType
+ Quoted string // The original text of the string, with quotes.
+ Text string // The string, after quote processing.
+}
+
+func newString(orig, text string) *StringNode {
+ return &StringNode{NodeType: NodeString, Quoted: orig, Text: text}
+}
+
+func (s *StringNode) String() string {
+ return s.Quoted
+}
+
+func (s *StringNode) Copy() Node {
+ return newString(s.Quoted, s.Text)
+}
+
+// endNode represents an {{end}} action. It is represented by a nil pointer.
+// It does not appear in the final parse tree.
+type endNode bool
+
+func newEnd() *endNode {
+ return nil
+}
+
+func (e *endNode) Type() NodeType {
+ return nodeEnd
+}
+
+func (e *endNode) String() string {
+ return "{{end}}"
+}
+
+func (e *endNode) Copy() Node {
+ return newEnd()
+}
+
+// elseNode represents an {{else}} action. Does not appear in the final tree.
+type elseNode struct {
+ NodeType
+ Line int // The line number in the input.
+}
+
+func newElse(line int) *elseNode {
+ return &elseNode{NodeType: nodeElse, Line: line}
+}
+
+func (e *elseNode) Type() NodeType {
+ return nodeElse
+}
+
+func (e *elseNode) String() string {
+ return "{{else}}"
+}
+
+func (e *elseNode) Copy() Node {
+ return newElse(e.Line)
+}
+
+// BranchNode is the common representation of if, range, and with.
+type BranchNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Pipe *PipeNode // The pipeline to be evaluated.
+ List *ListNode // What to execute if the value is non-empty.
+ ElseList *ListNode // What to execute if the value is empty (nil if absent).
+}
+
+func (b *BranchNode) String() string {
+ name := ""
+ switch b.NodeType {
+ case NodeIf:
+ name = "if"
+ case NodeRange:
+ name = "range"
+ case NodeWith:
+ name = "with"
+ default:
+ panic("unknown branch type")
+ }
+ if b.ElseList != nil {
+ return fmt.Sprintf("{{%s %s}}%s{{else}}%s{{end}}", name, b.Pipe, b.List, b.ElseList)
+ }
+ return fmt.Sprintf("{{%s %s}}%s{{end}}", name, b.Pipe, b.List)
+}
+
+// IfNode represents an {{if}} action and its commands.
+type IfNode struct {
+ BranchNode
+}
+
+func newIf(line int, pipe *PipeNode, list, elseList *ListNode) *IfNode {
+ return &IfNode{BranchNode{NodeType: NodeIf, Line: line, Pipe: pipe, List: list, ElseList: elseList}}
+}
+
+func (i *IfNode) Copy() Node {
+ return newIf(i.Line, i.Pipe.CopyPipe(), i.List.CopyList(), i.ElseList.CopyList())
+}
+
+// RangeNode represents a {{range}} action and its commands.
+type RangeNode struct {
+ BranchNode
+}
+
+func newRange(line int, pipe *PipeNode, list, elseList *ListNode) *RangeNode {
+ return &RangeNode{BranchNode{NodeType: NodeRange, Line: line, Pipe: pipe, List: list, ElseList: elseList}}
+}
+
+func (r *RangeNode) Copy() Node {
+ return newRange(r.Line, r.Pipe.CopyPipe(), r.List.CopyList(), r.ElseList.CopyList())
+}
+
+// WithNode represents a {{with}} action and its commands.
+type WithNode struct {
+ BranchNode
+}
+
+func newWith(line int, pipe *PipeNode, list, elseList *ListNode) *WithNode {
+ return &WithNode{BranchNode{NodeType: NodeWith, Line: line, Pipe: pipe, List: list, ElseList: elseList}}
+}
+
+func (w *WithNode) Copy() Node {
+ return newWith(w.Line, w.Pipe.CopyPipe(), w.List.CopyList(), w.ElseList.CopyList())
+}
+
+// TemplateNode represents a {{template}} action.
+type TemplateNode struct {
+ NodeType
+ Line int // The line number in the input.
+ Name string // The name of the template (unquoted).
+ Pipe *PipeNode // The command to evaluate as dot for the template.
+}
+
+func newTemplate(line int, name string, pipe *PipeNode) *TemplateNode {
+ return &TemplateNode{NodeType: NodeTemplate, Line: line, Name: name, Pipe: pipe}
+}
+
+func (t *TemplateNode) String() string {
+ if t.Pipe == nil {
+ return fmt.Sprintf("{{template %q}}", t.Name)
+ }
+ return fmt.Sprintf("{{template %q %s}}", t.Name, t.Pipe)
+}
+
+func (t *TemplateNode) Copy() Node {
+ return newTemplate(t.Line, t.Name, t.Pipe.CopyPipe())
+}
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-22 22:18:11 +0000