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Package parse

import "text/template/parse"
Overview
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Overview ▾

Package parse builds parse trees for templates as defined by text/template and html/template. Clients should use those packages to construct templates rather than this one, which provides shared internal data structures not intended for general use.

Index ▾

func IsEmptyTree(n Node) bool
func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]interface{}) (treeSet map[string]*Tree, err error)
type ActionNode
    func (a *ActionNode) Copy() Node
    func (a *ActionNode) String() string
type BoolNode
    func (b *BoolNode) Copy() Node
    func (b *BoolNode) String() string
type BranchNode
    func (b *BranchNode) String() string
type ChainNode
    func (c *ChainNode) Add(field string)
    func (c *ChainNode) Copy() Node
    func (c *ChainNode) String() string
type CommandNode
    func (c *CommandNode) Copy() Node
    func (c *CommandNode) String() string
type DotNode
    func (d *DotNode) Copy() Node
    func (d *DotNode) String() string
    func (d *DotNode) Type() NodeType
type FieldNode
    func (f *FieldNode) Copy() Node
    func (f *FieldNode) String() string
type IdentifierNode
    func NewIdentifier(ident string) *IdentifierNode
    func (i *IdentifierNode) Copy() Node
    func (i *IdentifierNode) SetPos(pos Pos) *IdentifierNode
    func (i *IdentifierNode) String() string
type IfNode
    func (i *IfNode) Copy() Node
type ListNode
    func (l *ListNode) Copy() Node
    func (l *ListNode) CopyList() *ListNode
    func (l *ListNode) String() string
type NilNode
    func (n *NilNode) Copy() Node
    func (n *NilNode) String() string
    func (n *NilNode) Type() NodeType
type Node
type NodeType
    func (t NodeType) Type() NodeType
type NumberNode
    func (n *NumberNode) Copy() Node
    func (n *NumberNode) String() string
type PipeNode
    func (p *PipeNode) Copy() Node
    func (p *PipeNode) CopyPipe() *PipeNode
    func (p *PipeNode) String() string
type Pos
    func (p Pos) Position() Pos
type RangeNode
    func (r *RangeNode) Copy() Node
type StringNode
    func (s *StringNode) Copy() Node
    func (s *StringNode) String() string
type TemplateNode
    func (t *TemplateNode) Copy() Node
    func (t *TemplateNode) String() string
type TextNode
    func (t *TextNode) Copy() Node
    func (t *TextNode) String() string
type Tree
    func New(name string, funcs ...map[string]interface{}) *Tree
    func (t *Tree) Copy() *Tree
    func (t *Tree) ErrorContext(n Node) (location, context string)
    func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error)
type VariableNode
    func (v *VariableNode) Copy() Node
    func (v *VariableNode) String() string
type WithNode
    func (w *WithNode) Copy() Node

Package files

lex.go node.go parse.go

func IsEmptyTree

func IsEmptyTree(n Node) bool

IsEmptyTree reports whether this tree (node) is empty of everything but space.

func Parse

func Parse(name, text, leftDelim, rightDelim string, funcs ...map[string]interface{}) (treeSet map[string]*Tree, err error)

Parse returns a map from template name to parse.Tree, created by parsing the templates described in the argument string. The top-level template will be given the specified name. If an error is encountered, parsing stops and an empty map is returned with the error.

type ActionNode

type ActionNode struct {
        NodeType
        Pos
        Line int       // The line number in the input (deprecated; kept for compatibility)
        Pipe *PipeNode // The pipeline in the action.
}

ActionNode holds an action (something bounded by delimiters). Control actions have their own nodes; ActionNode represents simple ones such as field evaluations and parenthesized pipelines.

func (*ActionNode) Copy

func (a *ActionNode) Copy() Node

func (*ActionNode) String

func (a *ActionNode) String() string

type BoolNode

type BoolNode struct {
        NodeType
        Pos
        True bool // The value of the boolean constant.
}

BoolNode holds a boolean constant.

func (*BoolNode) Copy

func (b *BoolNode) Copy() Node

func (*BoolNode) String

func (b *BoolNode) String() string

type BranchNode

type BranchNode struct {
        NodeType
        Pos
        Line     int       // The line number in the input (deprecated; kept for compatibility)
        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).
}

BranchNode is the common representation of if, range, and with.

func (*BranchNode) String

func (b *BranchNode) String() string

type ChainNode

type ChainNode struct {
        NodeType
        Pos
        Node  Node
        Field []string // The identifiers in lexical order.
}

ChainNode holds a term followed by a chain of field accesses (identifier starting with '.'). The names may be chained ('.x.y'). The periods are dropped from each ident.

func (*ChainNode) Add

func (c *ChainNode) Add(field string)

Add adds the named field (which should start with a period) to the end of the chain.

func (*ChainNode) Copy

func (c *ChainNode) Copy() Node

func (*ChainNode) String

func (c *ChainNode) String() string

type CommandNode

type CommandNode struct {
        NodeType
        Pos
        Args []Node // Arguments in lexical order: Identifier, field, or constant.
}

CommandNode holds a command (a pipeline inside an evaluating action).

func (*CommandNode) Copy

func (c *CommandNode) Copy() Node

func (*CommandNode) String

func (c *CommandNode) String() string

type DotNode

type DotNode struct {
        Pos
}

DotNode holds the special identifier '.'.

func (*DotNode) Copy

func (d *DotNode) Copy() Node

func (*DotNode) String

func (d *DotNode) String() string

func (*DotNode) Type

func (d *DotNode) Type() NodeType

type FieldNode

type FieldNode struct {
        NodeType
        Pos
        Ident []string // The identifiers in lexical order.
}

FieldNode holds a field (identifier starting with '.'). The names may be chained ('.x.y'). The period is dropped from each ident.

func (*FieldNode) Copy

func (f *FieldNode) Copy() Node

func (*FieldNode) String

func (f *FieldNode) String() string

type IdentifierNode

type IdentifierNode struct {
        NodeType
        Pos
        Ident string // The identifier's name.
}

IdentifierNode holds an identifier.

func NewIdentifier

func NewIdentifier(ident string) *IdentifierNode

NewIdentifier returns a new IdentifierNode with the given identifier name.

func (*IdentifierNode) Copy

func (i *IdentifierNode) Copy() Node

func (*IdentifierNode) SetPos

func (i *IdentifierNode) SetPos(pos Pos) *IdentifierNode

SetPos sets the position. NewIdentifier is a public method so we can't modify its signature. Chained for convenience. TODO: fix one day?

func (*IdentifierNode) String

func (i *IdentifierNode) String() string

type IfNode

type IfNode struct {
        BranchNode
}

IfNode represents an {{if}} action and its commands.

func (*IfNode) Copy

func (i *IfNode) Copy() Node

type ListNode

type ListNode struct {
        NodeType
        Pos
        Nodes []Node // The element nodes in lexical order.
}

ListNode holds a sequence of nodes.

func (*ListNode) Copy

func (l *ListNode) Copy() Node

func (*ListNode) CopyList

func (l *ListNode) CopyList() *ListNode

func (*ListNode) String

func (l *ListNode) String() string

type NilNode

type NilNode struct {
        Pos
}

NilNode holds the special identifier 'nil' representing an untyped nil constant.

func (*NilNode) Copy

func (n *NilNode) Copy() Node

func (*NilNode) String

func (n *NilNode) String() string

func (*NilNode) Type

func (n *NilNode) Type() NodeType

type Node

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
        Position() Pos // byte position of start of node in full original input string
        // contains filtered or unexported methods
}

A Node is an element in the parse tree. The interface is trivial. The interface contains an unexported method so that only types local to this package can satisfy it.

type NodeType

type NodeType int

NodeType identifies the type of a parse tree node.

const (
        NodeText    NodeType = iota // Plain text.
        NodeAction                  // A non-control action such as a field evaluation.
        NodeBool                    // A boolean constant.
        NodeChain                   // A sequence of field accesses.
        NodeCommand                 // An element of a pipeline.
        NodeDot                     // The cursor, dot.

        NodeField      // A field or method name.
        NodeIdentifier // An identifier; always a function name.
        NodeIf         // An if action.
        NodeList       // A list of Nodes.
        NodeNil        // An untyped nil constant.
        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.
)

func (NodeType) Type

func (t NodeType) Type() NodeType

Type returns itself and provides an easy default implementation for embedding in a Node. Embedded in all non-trivial Nodes.

type NumberNode

type NumberNode struct {
        NodeType
        Pos
        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.
}

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.

func (*NumberNode) Copy

func (n *NumberNode) Copy() Node

func (*NumberNode) String

func (n *NumberNode) String() string

type PipeNode

type PipeNode struct {
        NodeType
        Pos
        Line int             // The line number in the input (deprecated; kept for compatibility)
        Decl []*VariableNode // Variable declarations in lexical order.
        Cmds []*CommandNode  // The commands in lexical order.
}

PipeNode holds a pipeline with optional declaration

func (*PipeNode) Copy

func (p *PipeNode) Copy() Node

func (*PipeNode) CopyPipe

func (p *PipeNode) CopyPipe() *PipeNode

func (*PipeNode) String

func (p *PipeNode) String() string

type Pos

type Pos int

Pos represents a byte position in the original input text from which this template was parsed.

func (Pos) Position

func (p Pos) Position() Pos

type RangeNode

type RangeNode struct {
        BranchNode
}

RangeNode represents a {{range}} action and its commands.

func (*RangeNode) Copy

func (r *RangeNode) Copy() Node

type StringNode

type StringNode struct {
        NodeType
        Pos
        Quoted string // The original text of the string, with quotes.
        Text   string // The string, after quote processing.
}

StringNode holds a string constant. The value has been "unquoted".

func (*StringNode) Copy

func (s *StringNode) Copy() Node

func (*StringNode) String

func (s *StringNode) String() string

type TemplateNode

type TemplateNode struct {
        NodeType
        Pos
        Line int       // The line number in the input (deprecated; kept for compatibility)
        Name string    // The name of the template (unquoted).
        Pipe *PipeNode // The command to evaluate as dot for the template.
}

TemplateNode represents a {{template}} action.

func (*TemplateNode) Copy

func (t *TemplateNode) Copy() Node

func (*TemplateNode) String

func (t *TemplateNode) String() string

type TextNode

type TextNode struct {
        NodeType
        Pos
        Text []byte // The text; may span newlines.
}

TextNode holds plain text.

func (*TextNode) Copy

func (t *TextNode) Copy() Node

func (*TextNode) String

func (t *TextNode) String() string

type Tree

type Tree struct {
        Name      string    // name of the template represented by the tree.
        ParseName string    // name of the top-level template during parsing, for error messages.
        Root      *ListNode // top-level root of the tree.
        // contains filtered or unexported fields
}

Tree is the representation of a single parsed template.

func New

func New(name string, funcs ...map[string]interface{}) *Tree

New allocates a new parse tree with the given name.

func (*Tree) Copy

func (t *Tree) Copy() *Tree

Copy returns a copy of the Tree. Any parsing state is discarded.

func (*Tree) ErrorContext

func (t *Tree) ErrorContext(n Node) (location, context string)

ErrorContext returns a textual representation of the location of the node in the input text.

func (*Tree) Parse

func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]interface{}) (tree *Tree, err error)

Parse parses the template definition string to construct a representation of the template for execution. If either action delimiter string is empty, the default ("{{" or "}}") is used. Embedded template definitions are added to the treeSet map.

type VariableNode

type VariableNode struct {
        NodeType
        Pos
        Ident []string // Variable name and fields in lexical order.
}

VariableNode holds a list of variable names, possibly with chained field accesses. The dollar sign is part of the (first) name.

func (*VariableNode) Copy

func (v *VariableNode) Copy() Node

func (*VariableNode) String

func (v *VariableNode) String() string

type WithNode

type WithNode struct {
        BranchNode
}

WithNode represents a {{with}} action and its commands.

func (*WithNode) Copy

func (w *WithNode) Copy() Node