ast

package
v1.23.1 Latest Latest
Warning

This package is not in the latest version of its module.

 Go to latest Published: May 18, 2023 License: MIT Imports: 4 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	V_ILLEGAL = iota
	V_ARGC
	V_CONVFMT
	V_FILENAME
	V_FNR
	V_FS
	V_INPUTMODE
	V_NF
	V_NR
	V_OFMT
	V_OFS
	V_ORS
	V_OUTPUTMODE
	V_RLENGTH
	V_RS
	V_RSTART
	V_RT
	V_SUBSEP

	V_LAST = V_SUBSEP
)

Variables

This section is empty.

Functions

func IsLValue 

func IsLValue(expr Expr) bool

IsLValue returns true if the given expression can be used as an lvalue (on the left-hand side of an assignment, in a ++ or -- operation, or as the third argument to sub or gsub).

func PosErrorf added in v1.21.0 

func PosErrorf(pos Position, format string, args ...interface{}) error

PosErrorf like fmt.Errorf, but with an explicit position.

func SpecialVarIndex 

func SpecialVarIndex(name string) int

SpecialVarIndex returns the "index" of the special variable, or 0 if it's not a special variable.

func SpecialVarName added in v1.15.0 

func SpecialVarName(index int) string

SpecialVarName returns the name of the special variable by index.

func Walk added in v1.21.0 

func Walk(v Visitor, node Node)

Walk traverses an AST in depth-first order: It starts by calling v.Visit(node); if node is nil, it does nothing. If the visitor w returned by v.Visit(node) is not nil, Walk is invoked recursively with visitor w for each of the non-nil children of node, followed by a call of w.Visit(nil).

func WalkExprList added in v1.21.0 

func WalkExprList(v Visitor, exprs []Expr)

WalkExprList walks a visitor over a list of expression AST nodes

func WalkStmtList added in v1.21.0 

func WalkStmtList(v Visitor, stmts []Stmt)

WalkStmtList walks a visitor over a list of statement AST nodes

Types

type Action 

type Action struct {
	Pattern []Expr
	Stmts   Stmts
}

Action is pattern-action section of a program.

func (*Action) String 

func (a *Action) String() string

type AssignExpr 

type AssignExpr struct {
	Left  Expr // can be one of: var, array[x], $n
	Right Expr
}

AssignExpr is an expression like x = 1234.

func (*AssignExpr) String 

func (e *AssignExpr) String() string

type AugAssignExpr 

type AugAssignExpr struct {
	Left  Expr // can be one of: var, array[x], $n
	Op    Token
	Right Expr
}

AugAssignExpr is an assignment expression like x += 5.

func (*AugAssignExpr) String 

func (e *AugAssignExpr) String() string

type BinaryExpr 

type BinaryExpr struct {
	Left  Expr
	Op    Token
	Right Expr
}

BinaryExpr is an expression like 1 + 2.

func (*BinaryExpr) String 

func (e *BinaryExpr) String() string

type BlockStmt 

type BlockStmt struct {
	Body  Stmts
	Start Position
	End   Position
}

BlockStmt is a stand-alone block like { print "x" }.

func (*BlockStmt) EndPos added in v1.21.0 

func (s *BlockStmt) EndPos() Position

func (*BlockStmt) StartPos added in v1.21.0 

func (s *BlockStmt) StartPos() Position

func (*BlockStmt) String 

func (s *BlockStmt) String() string

type BreakStmt 

type BreakStmt struct {
	Start Position
	End   Position
}

BreakStmt is a break statement.

func (*BreakStmt) EndPos added in v1.21.0 

func (s *BreakStmt) EndPos() Position

func (*BreakStmt) StartPos added in v1.21.0 

func (s *BreakStmt) StartPos() Position

func (*BreakStmt) String 

func (s *BreakStmt) String() string

type CallExpr 

type CallExpr struct {
	Func Token
	Args []Expr
}

CallExpr is a builtin function call like length($1).

func (*CallExpr) String 

func (e *CallExpr) String() string

type CondExpr 

type CondExpr struct {
	Cond  Expr
	True  Expr
	False Expr
}

CondExpr is an expression like cond ? 1 : 0.

func (*CondExpr) String 

func (e *CondExpr) String() string

type ContinueStmt 

type ContinueStmt struct {
	Start Position
	End   Position
}

ContinueStmt is a continue statement.

func (*ContinueStmt) EndPos added in v1.21.0 

func (s *ContinueStmt) EndPos() Position

func (*ContinueStmt) StartPos added in v1.21.0 

func (s *ContinueStmt) StartPos() Position

func (*ContinueStmt) String 

func (s *ContinueStmt) String() string

type DeleteStmt 

type DeleteStmt struct {
	Array    string
	ArrayPos Position
	Index    []Expr
	Start    Position
	End      Position
}

DeleteStmt is a statement like delete a[k].

func (*DeleteStmt) EndPos added in v1.21.0 

func (s *DeleteStmt) EndPos() Position

func (*DeleteStmt) StartPos added in v1.21.0 

func (s *DeleteStmt) StartPos() Position

func (*DeleteStmt) String 

func (s *DeleteStmt) String() string

type DoWhileStmt 

type DoWhileStmt struct {
	Body  Stmts
	Cond  Expr
	Start Position
	End   Position
}

DoWhileStmt is a do-while loop.

func (*DoWhileStmt) EndPos added in v1.21.0 

func (s *DoWhileStmt) EndPos() Position

func (*DoWhileStmt) StartPos added in v1.21.0 

func (s *DoWhileStmt) StartPos() Position

func (*DoWhileStmt) String 

func (s *DoWhileStmt) String() string

type ExitStmt 

type ExitStmt struct {
	Status Expr
	Start  Position
	End    Position
}

ExitStmt is an exit statement.

func (*ExitStmt) EndPos added in v1.21.0 

func (s *ExitStmt) EndPos() Position

func (*ExitStmt) StartPos added in v1.21.0 

func (s *ExitStmt) StartPos() Position

func (*ExitStmt) String 

func (s *ExitStmt) String() string

type Expr 

type Expr interface {
	Node

	String() string
	// contains filtered or unexported methods
}

Expr is the abstract syntax tree for any AWK expression.

type ExprStmt 

type ExprStmt struct {
	Expr  Expr
	Start Position
	End   Position
}

ExprStmt is statement like a bare function call: my_func(x).

func (*ExprStmt) EndPos added in v1.21.0 

func (s *ExprStmt) EndPos() Position

func (*ExprStmt) StartPos added in v1.21.0 

func (s *ExprStmt) StartPos() Position

func (*ExprStmt) String 

func (s *ExprStmt) String() string

type FieldExpr 

type FieldExpr struct {
	Index Expr
}

FieldExpr is an expression like $0.

func (*FieldExpr) String 

func (e *FieldExpr) String() string

type ForInStmt 

type ForInStmt struct {
	Var       string
	VarPos    Position
	Array     string
	ArrayPos  Position
	BodyStart Position
	Body      Stmts
	Start     Position
	End       Position
}

ForInStmt is a for loop like for (k in a) print k, a[k].

func (*ForInStmt) EndPos added in v1.21.0 

func (s *ForInStmt) EndPos() Position

func (*ForInStmt) StartPos added in v1.21.0 

func (s *ForInStmt) StartPos() Position

func (*ForInStmt) String 

func (s *ForInStmt) String() string

type ForStmt 

type ForStmt struct {
	Pre       Stmt
	Cond      Expr
	Post      Stmt
	BodyStart Position
	Body      Stmts
	Start     Position
	End       Position
}

ForStmt is a C-like for loop: for (i=0; i<10; i++) print i.

func (*ForStmt) EndPos added in v1.21.0 

func (s *ForStmt) EndPos() Position

func (*ForStmt) StartPos added in v1.21.0 

func (s *ForStmt) StartPos() Position

func (*ForStmt) String 

func (s *ForStmt) String() string

type Function 

type Function struct {
	Name   string
	Params []string
	Body   Stmts
	Pos    Position
}

Function is the AST for a user-defined function.

func (*Function) String 

func (f *Function) String() string

type GetlineExpr 

type GetlineExpr struct {
	Command Expr
	Target  Expr
	File    Expr
}

GetlineExpr is an expression read from file or pipe input.

func (*GetlineExpr) String 

func (e *GetlineExpr) String() string

type GroupingExpr added in v1.22.0 

type GroupingExpr struct {
	Expr Expr
}

GroupingExpr is a parenthesized grouping expression.

func (*GroupingExpr) String added in v1.22.0 

func (e *GroupingExpr) String() string

type IfStmt 

type IfStmt struct {
	Cond      Expr
	BodyStart Position
	Body      Stmts
	Else      Stmts
	Start     Position
	End       Position
}

IfStmt is an if or if-else statement.

func (*IfStmt) EndPos added in v1.21.0 

func (s *IfStmt) EndPos() Position

func (*IfStmt) StartPos added in v1.21.0 

func (s *IfStmt) StartPos() Position

func (*IfStmt) String 

func (s *IfStmt) String() string

type InExpr 

type InExpr struct {
	Index    []Expr
	Array    string
	ArrayPos Position
}

InExpr is an expression like (index in array).

func (*InExpr) String 

func (e *InExpr) String() string

type IncrExpr 

type IncrExpr struct {
	Expr Expr
	Op   Token
	Pre  bool
}

IncrExpr is an increment or decrement expression like x++ or --y.

func (*IncrExpr) String 

func (e *IncrExpr) String() string

type IndexExpr 

type IndexExpr struct {
	Array    string
	ArrayPos Position
	Index    []Expr
}

IndexExpr is an expression like a[k] (rvalue or lvalue).

func (*IndexExpr) String 

func (e *IndexExpr) String() string

type MultiExpr 

type MultiExpr struct {
	Exprs []Expr
}

MultiExpr isn't an interpretable expression, but it's used as a pseudo-expression for print[f] parsing.

func (*MultiExpr) String 

func (e *MultiExpr) String() string

type NamedFieldExpr added in v1.17.0 

type NamedFieldExpr struct {
	Field Expr
}

NamedFieldExpr is an expression like @"name".

func (*NamedFieldExpr) String added in v1.17.0 

func (e *NamedFieldExpr) String() string

type NextStmt 

type NextStmt struct {
	Start Position
	End   Position
}

NextStmt is a next statement.

func (*NextStmt) EndPos added in v1.21.0 

func (s *NextStmt) EndPos() Position

func (*NextStmt) StartPos added in v1.21.0 

func (s *NextStmt) StartPos() Position

func (*NextStmt) String 

func (s *NextStmt) String() string

type NextfileStmt added in v1.22.0 

type NextfileStmt struct {
	Start Position
	End   Position
}

NextfileStmt is a nextfile statement.

func (*NextfileStmt) EndPos added in v1.22.0 

func (s *NextfileStmt) EndPos() Position

func (*NextfileStmt) StartPos added in v1.22.0 

func (s *NextfileStmt) StartPos() Position

func (*NextfileStmt) String added in v1.22.0 

func (s *NextfileStmt) String() string

type Node added in v1.21.0 

type Node interface {
	// contains filtered or unexported methods
}

Node is an interface to be satisfied by all AST elements. We need it to be able to work with AST in a generic way, like in ast.Walk().

type NumExpr 

type NumExpr struct {
	Value float64
}

NumExpr is a literal number like 1234.

func (*NumExpr) String 

func (e *NumExpr) String() string

type PositionError added in v1.21.0 

type PositionError struct {
	// Source line/column position where the error occurred.
	Position Position
	// Error message.
	Message string
}

PositionError represents an error bound to specific position in source.

func (*PositionError) Error added in v1.21.0 

func (e *PositionError) Error() string

Error returns a formatted version of the error, including the line and column numbers.

type PrintStmt 

type PrintStmt struct {
	Args     []Expr
	Redirect Token
	Dest     Expr
	Start    Position
	End      Position
}

PrintStmt is a statement like print $1, $3.

func (*PrintStmt) EndPos added in v1.21.0 

func (s *PrintStmt) EndPos() Position

func (*PrintStmt) StartPos added in v1.21.0 

func (s *PrintStmt) StartPos() Position

func (*PrintStmt) String 

func (s *PrintStmt) String() string

type PrintfStmt 

type PrintfStmt struct {
	Args     []Expr
	Redirect Token
	Dest     Expr
	Start    Position
	End      Position
}

PrintfStmt is a statement like printf "%3d", 1234.

func (*PrintfStmt) EndPos added in v1.21.0 

func (s *PrintfStmt) EndPos() Position

func (*PrintfStmt) StartPos added in v1.21.0 

func (s *PrintfStmt) StartPos() Position

func (*PrintfStmt) String 

func (s *PrintfStmt) String() string

type Program added in v1.15.0 

type Program struct {
	Begin     []Stmts
	Actions   []*Action
	End       []Stmts
	Functions []*Function
}

Program is a parsed AWK program.

func (*Program) String added in v1.15.0 

func (p *Program) String() string

String returns an indented, pretty-printed version of the parsed program.

type RegExpr 

type RegExpr struct {
	Regex string
}

RegExpr is a stand-alone regex expression, equivalent to: $0 ~ /regex/.

func (*RegExpr) String 

func (e *RegExpr) String() string

type ReturnStmt 

type ReturnStmt struct {
	Value Expr
	Start Position
	End   Position
}

ReturnStmt is a return statement.

func (*ReturnStmt) EndPos added in v1.21.0 

func (s *ReturnStmt) EndPos() Position

func (*ReturnStmt) StartPos added in v1.21.0 

func (s *ReturnStmt) StartPos() Position

func (*ReturnStmt) String 

func (s *ReturnStmt) String() string

type Stmt 

type Stmt interface {
	Node
	StartPos() Position // position of first character belonging to the node
	EndPos() Position   // position of first character immediately after the node

	String() string
	// contains filtered or unexported methods
}

Stmt is the abstract syntax tree for any AWK statement.

type Stmts 

type Stmts []Stmt

Stmts is a block containing multiple statements.

func (Stmts) String 

func (ss Stmts) String() string

type StrExpr 

type StrExpr struct {
	Value string
}

StrExpr is a literal string like "foo".

func (*StrExpr) String 

func (e *StrExpr) String() string

type UnaryExpr 

type UnaryExpr struct {
	Op    Token
	Value Expr
}

UnaryExpr is an expression like -1234.

func (*UnaryExpr) String 

func (e *UnaryExpr) String() string

type UserCallExpr 

type UserCallExpr struct {
	Name string
	Args []Expr
	Pos  Position
}

UserCallExpr is a user-defined function call like my_func(1, 2, 3), where my_func is either AWK-defined or a native Go function.

func (*UserCallExpr) String 

func (e *UserCallExpr) String() string

type VarExpr 

type VarExpr struct {
	Name string
	Pos  Position
}

VarExpr is a variable reference (special var, global, or local).

func (*VarExpr) String 

func (e *VarExpr) String() string

type Visitor added in v1.21.0 

type Visitor interface {
	Visit(node Node) (w Visitor)
}

Visitor has a Visit method which is invoked for each node encountered by Walk. If the result visitor w is not nil, Walk visits each of the children of node with the visitor w, followed by a call of w.Visit(nil).

type WhileStmt 

type WhileStmt struct {
	Cond      Expr
	BodyStart Position
	Body      Stmts
	Start     Position
	End       Position
}

WhileStmt is a while loop.

func (*WhileStmt) EndPos added in v1.21.0 

func (s *WhileStmt) EndPos() Position

func (*WhileStmt) StartPos added in v1.21.0 

func (s *WhileStmt) StartPos() Position

func (*WhileStmt) String 

func (s *WhileStmt) String() string

Source Files

View all Source files

Jump to

Keyboard shortcuts

? : This menu
/ : Search site
f or F : Jump to
y or Y : Canonical URL
go.dev uses cookies from Google to deliver and enhance the quality of its services and to analyze traffic. Learn more.