Package parse

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

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 or comments.

func Parse

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

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.

type ActionNode struct {
    NodeType
    Pos

    Line int       // The line number in the input. Deprecated: Kept for compatibility.
    Pipe *PipeNode // The pipeline in the action.
    // contains filtered or unexported fields
}

func (*ActionNode) Copy

func (a *ActionNode) Copy() Node

func (*ActionNode) String

func (a *ActionNode) String() string

type BoolNode

BoolNode holds a boolean constant.

type BoolNode struct {
    NodeType
    Pos

    True bool // The value of the boolean constant.
    // contains filtered or unexported fields
}

func (*BoolNode) Copy

func (b *BoolNode) Copy() Node

func (*BoolNode) String

func (b *BoolNode) String() string

type BranchNode

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

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).
    // contains filtered or unexported fields
}

func (*BranchNode) Copy 1.4

func (b *BranchNode) Copy() Node

func (*BranchNode) String

func (b *BranchNode) String() string

type ChainNode 1.1

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.

type ChainNode struct {
    NodeType
    Pos

    Node  Node
    Field []string // The identifiers in lexical order.
    // contains filtered or unexported fields
}

func (*ChainNode) Add 1.1

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 1.1

func (c *ChainNode) Copy() Node

func (*ChainNode) String 1.1

func (c *ChainNode) String() string

type CommandNode

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

type CommandNode struct {
    NodeType
    Pos

    Args []Node // Arguments in lexical order: Identifier, field, or constant.
    // contains filtered or unexported fields
}

func (*CommandNode) Copy

func (c *CommandNode) Copy() Node

func (*CommandNode) String

func (c *CommandNode) String() string

type CommentNode 1.16

CommentNode holds a comment.

type CommentNode struct {
    NodeType
    Pos

    Text string // Comment text.
    // contains filtered or unexported fields
}

func (*CommentNode) Copy 1.16

func (c *CommentNode) Copy() Node

func (*CommentNode) String 1.16

func (c *CommentNode) String() string

type DotNode

DotNode holds the special identifier '.'.

type DotNode struct {
    NodeType
    Pos
    // contains filtered or unexported fields
}

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

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
    Pos

    Ident []string // The identifiers in lexical order.
    // contains filtered or unexported fields
}

func (*FieldNode) Copy

func (f *FieldNode) Copy() Node

func (*FieldNode) String

func (f *FieldNode) String() string

type IdentifierNode

IdentifierNode holds an identifier.

type IdentifierNode struct {
    NodeType
    Pos

    Ident string // The identifier's name.
    // contains filtered or unexported fields
}

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 1.1

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) SetTree 1.4

func (i *IdentifierNode) SetTree(t *Tree) *IdentifierNode

SetTree sets the parent tree for the node. 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

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

type IfNode struct {
    BranchNode
}

func (*IfNode) Copy

func (i *IfNode) Copy() Node

type ListNode

ListNode holds a sequence of nodes.

type ListNode struct {
    NodeType
    Pos

    Nodes []Node // The element nodes in lexical order.
    // contains filtered or unexported fields
}

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 Mode 1.16

A mode value is a set of flags (or 0). Modes control parser behavior.

type Mode uint
const (
    ParseComments Mode = 1 << iota // parse comments and add them to AST
    SkipFuncCheck                  // do not check that functions are defined
)

type NilNode 1.1

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

type NilNode struct {
    NodeType
    Pos
    // contains filtered or unexported fields
}

func (*NilNode) Copy 1.1

func (n *NilNode) Copy() Node

func (*NilNode) String 1.1

func (n *NilNode) String() string

func (*NilNode) Type 1.1

func (n *NilNode) Type() NodeType

type Node

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 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
}

type NodeType

NodeType identifies the type of a parse tree node.

type NodeType int
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.
    NodeComment    // A comment.
)

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

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
    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.
    // contains filtered or unexported fields
}

func (*NumberNode) Copy

func (n *NumberNode) Copy() Node

func (*NumberNode) String

func (n *NumberNode) String() string

type PipeNode

PipeNode holds a pipeline with optional declaration

type PipeNode struct {
    NodeType
    Pos

    Line     int             // The line number in the input. Deprecated: Kept for compatibility.
    IsAssign bool            // The variables are being assigned, not declared; added in Go 1.11
    Decl     []*VariableNode // Variables in lexical order.
    Cmds     []*CommandNode  // The commands in lexical order.
    // contains filtered or unexported fields
}

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 1.1

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

type Pos int

func (Pos) Position 1.1

func (p Pos) Position() Pos

type RangeNode

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

type RangeNode struct {
    BranchNode
}

func (*RangeNode) Copy

func (r *RangeNode) Copy() Node

type StringNode

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

type StringNode struct {
    NodeType
    Pos

    Quoted string // The original text of the string, with quotes.
    Text   string // The string, after quote processing.
    // contains filtered or unexported fields
}

func (*StringNode) Copy

func (s *StringNode) Copy() Node

func (*StringNode) String

func (s *StringNode) String() string

type TemplateNode

TemplateNode represents a {{template}} action.

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.
    // contains filtered or unexported fields
}

func (*TemplateNode) Copy

func (t *TemplateNode) Copy() Node

func (*TemplateNode) String

func (t *TemplateNode) String() string

type TextNode

TextNode holds plain text.

type TextNode struct {
    NodeType
    Pos

    Text []byte // The text; may span newlines.
    // contains filtered or unexported fields
}

func (*TextNode) Copy

func (t *TextNode) Copy() Node

func (*TextNode) String

func (t *TextNode) String() string

type Tree

Tree is the representation of a single parsed template.

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; added in Go 1.1
    Root      *ListNode // top-level root of the tree.
    Mode      Mode      // parsing mode; added in Go 1.16
    // contains filtered or unexported fields
}

func New

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

New allocates a new parse tree with the given name.

func (*Tree) Copy 1.2

func (t *Tree) Copy() *Tree

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

func (*Tree) ErrorContext 1.1

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

ErrorContext returns a textual representation of the location of the node in the input text. The receiver is only used when the node does not have a pointer to the tree inside, which can occur in old code.

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

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

type VariableNode struct {
    NodeType
    Pos

    Ident []string // Variable name and fields in lexical order.
    // contains filtered or unexported fields
}

func (*VariableNode) Copy

func (v *VariableNode) Copy() Node

func (*VariableNode) String

func (v *VariableNode) String() string

type WithNode

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

type WithNode struct {
    BranchNode
}

func (*WithNode) Copy

func (w *WithNode) Copy() Node

© Google, Inc.
Licensed under the Creative Commons Attribution License 3.0.
http://golang.org/pkg/text/template/parse/