Documentation
¶
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]any) (map[string]*Tree, error)
- type ActionNode
- type BoolNode
- type BranchNode
- type BreakNode
- type ChainNode
- type CommandNode
- type CommentNode
- type ContinueNode
- type DotNode
- type FieldNode
- type IdentifierNode
- type IfNode
- type ListNode
- type Mode
- type NilNode
- type Node
- type NodeType
- type NumberNode
- type PipeNode
- type Pos
- type RangeNode
- type StringNode
- type TemplateNode
- type TextNode
- type Tree
- type VariableNode
- type WithNode
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func IsEmptyTree ¶
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]any) (map[string]*Tree, error)
Parse returns a map from template name to 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.
Types ¶
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.
// contains filtered or unexported fields
}
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.
// contains filtered or unexported fields
}
BoolNode holds a boolean constant.
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).
// contains filtered or unexported fields
}
BranchNode is the common representation of if, range, and with.
func (*BranchNode) Copy ¶ added in go1.4
func (b *BranchNode) Copy() Node
func (*BranchNode) String ¶
func (b *BranchNode) String() string
type ChainNode ¶ added in go1.1
type ChainNode struct {
NodeType
Pos
Node Node
Field []string // The identifiers in lexical order.
// contains filtered or unexported fields
}
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 CommandNode ¶
type CommandNode struct {
NodeType
Pos
Args []Node // Arguments in lexical order: Identifier, field, or constant.
// contains filtered or unexported fields
}
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 CommentNode ¶ added in go1.16
type CommentNode struct {
NodeType
Pos
Text string // Comment text.
// contains filtered or unexported fields
}
CommentNode holds a comment.
func (*CommentNode) Copy ¶ added in go1.16
func (c *CommentNode) Copy() Node
func (*CommentNode) String ¶ added in go1.16
func (c *CommentNode) String() string
type ContinueNode ¶ added in go1.18
ContinueNode represents a {{continue}} action.
func (*ContinueNode) Copy ¶ added in go1.18
func (c *ContinueNode) Copy() Node
func (*ContinueNode) String ¶ added in go1.18
func (c *ContinueNode) String() string
type FieldNode ¶
type FieldNode struct {
NodeType
Pos
Ident []string // The identifiers in lexical order.
// contains filtered or unexported fields
}
FieldNode holds a field (identifier starting with '.'). The names may be chained ('.x.y'). The period is dropped from each ident.
type IdentifierNode ¶
type IdentifierNode struct {
NodeType
Pos
Ident string // The identifier's name.
// contains filtered or unexported fields
}
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 ¶ added in go1.1
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 ¶ added in go1.4
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 ¶
type IfNode struct {
BranchNode
}
IfNode represents an {{if}} action and its commands.
type ListNode ¶
type ListNode struct {
NodeType
Pos
Nodes []Node // The element nodes in lexical order.
// contains filtered or unexported fields
}
ListNode holds a sequence of nodes.
type Mode ¶ added in go1.16
type Mode uint
A Mode value is a set of flags (or 0). Modes control parser behavior.
type NilNode ¶ added in go1.1
NilNode holds the special identifier 'nil' representing an untyped nil constant.
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. NodeComment // A comment. NodeBreak // A break action. NodeContinue // A continue action. )
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.
// contains filtered or unexported fields
}
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.
IsAssign bool // The variables are being assigned, not declared.
Decl []*VariableNode // Variables in lexical order.
Cmds []*CommandNode // The commands in lexical order.
// contains filtered or unexported fields
}
PipeNode holds a pipeline with optional declaration
type Pos ¶ added in go1.1
type Pos int
Pos represents a byte position in the original input text from which this template was parsed.
type RangeNode ¶
type RangeNode struct {
BranchNode
}
RangeNode represents a {{range}} action and its commands.
type StringNode ¶
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
}
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.
// contains filtered or unexported fields
}
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.
// contains filtered or unexported fields
}
TextNode holds plain text.
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.
Mode Mode // parsing mode.
// contains filtered or unexported fields
}
Tree is the representation of a single parsed template.
func (*Tree) ErrorContext ¶ added in go1.1
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]any) (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.
// contains filtered or unexported fields
}
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
Source Files