func IsEmptyTree(n Node) bool
IsEmptyTree reports whether this tree (node) is empty of everything but space or comments.
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.
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 (a *ActionNode) Copy() Node
func (a *ActionNode) String() string
BoolNode holds a boolean constant.
type BoolNode struct {
NodeType
Pos
True bool // The value of the boolean constant.
// contains filtered or unexported fields
}
func (b *BoolNode) Copy() Node
func (b *BoolNode) String() string
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 (b *BranchNode) Copy() Node
func (b *BranchNode) String() string
BreakNode represents a {{break}} action.
type BreakNode struct {
NodeType
Pos
Line int
// contains filtered or unexported fields
}
func (b *BreakNode) Copy() Node
func (b *BreakNode) String() string
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 (c *ChainNode) Add(field string)
Add adds the named field (which should start with a period) to the end of the chain.
func (c *ChainNode) Copy() Node
func (c *ChainNode) String() string
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 (c *CommandNode) Copy() Node
func (c *CommandNode) String() string
CommentNode holds a comment.
type CommentNode struct {
NodeType
Pos
Text string // Comment text.
// contains filtered or unexported fields
}
func (c *CommentNode) Copy() Node
func (c *CommentNode) String() string
ContinueNode represents a {{continue}} action.
type ContinueNode struct {
NodeType
Pos
Line int
// contains filtered or unexported fields
}
func (c *ContinueNode) Copy() Node
func (c *ContinueNode) String() string
DotNode holds the special identifier '.'.
type DotNode struct {
NodeType
Pos
// contains filtered or unexported fields
}
func (d *DotNode) Copy() Node
func (d *DotNode) String() string
func (d *DotNode) Type() NodeType
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 (f *FieldNode) Copy() Node
func (f *FieldNode) String() string
IdentifierNode holds an identifier.
type IdentifierNode struct {
NodeType
Pos
Ident string // The identifier's name.
// contains filtered or unexported fields
}
func NewIdentifier(ident string) *IdentifierNode
NewIdentifier returns a new IdentifierNode with the given identifier name.
func (i *IdentifierNode) Copy() Node
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 (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 (i *IdentifierNode) String() string
IfNode represents an {{if}} action and its commands.
type IfNode struct {
BranchNode
}
func (i *IfNode) Copy() Node
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 (l *ListNode) Copy() Node
func (l *ListNode) CopyList() *ListNode
func (l *ListNode) String() string
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
)
NilNode holds the special identifier 'nil' representing an untyped nil constant.
type NilNode struct {
NodeType
Pos
// contains filtered or unexported fields
}
func (n *NilNode) Copy() Node
func (n *NilNode) String() string
func (n *NilNode) Type() NodeType
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
}
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.
NodeBreak // A break action.
NodeContinue // A continue action.
)
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.
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 (n *NumberNode) Copy() Node
func (n *NumberNode) String() string
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 (p *PipeNode) Copy() Node
func (p *PipeNode) CopyPipe() *PipeNode
func (p *PipeNode) String() string
Pos represents a byte position in the original input text from which this template was parsed.
type Pos int
func (p Pos) Position() Pos
RangeNode represents a {{range}} action and its commands.
type RangeNode struct {
BranchNode
}
func (r *RangeNode) Copy() Node
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 (s *StringNode) Copy() Node
func (s *StringNode) String() string
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 (t *TemplateNode) Copy() Node
func (t *TemplateNode) String() string
TextNode holds plain text.
type TextNode struct {
NodeType
Pos
Text []byte // The text; may span newlines.
// contains filtered or unexported fields
}
func (t *TextNode) Copy() Node
func (t *TextNode) String() string
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(name string, funcs ...map[string]any) *Tree
New allocates a new parse tree with the given name.
func (t *Tree) Copy() *Tree
Copy returns a copy of the Tree. Any parsing state is discarded.
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 (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.
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 (v *VariableNode) Copy() Node
func (v *VariableNode) String() string
WithNode represents a {{with}} action and its commands.
type WithNode struct {
BranchNode
}
func (w *WithNode) Copy() Node