ir

Documentation

Overview

Package ir defines an intermediate representation (IR) for Rego.

The IR specifies an imperative execution model for Rego policies similar to a query plan in traditional databases.

Index

• Constants
• func Pretty(w io.Writer, x interface{})
• func Walk(vis Visitor, x interface{}) error
• type AssignStmt
• type Block
  • func (a Block) String() string
• type BooleanConst
• type Const
• type DotStmt
• type EqualStmt
• type FloatConst
• type GreaterThanEqualStmt
• type GreaterThanStmt
• type IntConst
• type LessThanEqualStmt
• type LessThanStmt
• type Local
• type LoopStmt
• type MakeBooleanStmt
• type MakeNumberIntStmt
• type MakeStringStmt
• type NotEqualStmt
• type NullConst
• type Plan
  • func (a Plan) String() string
• type Policy
  • func (a Policy) String() string
• type ReturnStmt
• type Static
  • func (a Static) String() string
• type Stmt
• type StringConst
• type Visitor

Constants

const (
	// Undefined represents an undefined return value. An undefined return value
	// indicates the policy did not return a definitive answer.
	Undefined int32 = iota

	// Defined represents a defined return value.
	Defined

	// Error indicates a runtime error occurred during evaluation.
	Error
)

Functions

func Pretty

func Pretty(w io.Writer, x interface{})

Pretty writes a human-readable representation of an IR object to w.

func Walk

func Walk(vis Visitor, x interface{}) error

Walk invokes the visitor for nodes under x.

Types

type AssignStmt

type AssignStmt struct {
	Value  Const
	Target Local
}

AssignStmt represents an assignment of a local variable.

type Block

type Block struct {
	Stmts []Stmt
}

Block represents an ordered sequence of statements to execute. Blocks are executed until a return statement is encountered, a statement is undefined, or there are no more statements. If all statements are defined but no return statement is encountered, the block is undefined.

func (Block) String

func (a Block) String() string

type BooleanConst

type BooleanConst struct {
	Value bool
}

BooleanConst represents a boolean value.

type Const

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

Const represents a constant value from the policy.

type DotStmt

type DotStmt struct {
	Source Local
	Key    Local
	Target Local
}

DotStmt represents a lookup operation on a value (e.g., array, object, etc.) The source of a DotStmt may be a scalar value in which case the statement will be undefined.

type EqualStmt

type EqualStmt struct {
	A Local
	B Local
}

EqualStmt represents an value-equality check of two local variables.

type FloatConst

type FloatConst struct {
	Value float64
}

FloatConst represents a floating-point constant.

type GreaterThanEqualStmt

type GreaterThanEqualStmt struct {
	A Local
	B Local
}

GreaterThanEqualStmt represents a >= check of two local variables.

type GreaterThanStmt

type GreaterThanStmt struct {
	A Local
	B Local
}

GreaterThanStmt represents a > check of two local variables.

type IntConst

type IntConst struct {
	Value int64
}

IntConst represents an integer constant.

type LessThanEqualStmt

type LessThanEqualStmt struct {
	A Local
	B Local
}

LessThanEqualStmt represents a <= check of two local variables.

type LessThanStmt

type LessThanStmt struct {
	A Local
	B Local
}

LessThanStmt represents a < check of two local variables.

type Local

type Local int

Local represents a plan-scoped variable.

const (
	// InputRaw refers to the local variable containing the address of the raw
	// (serialized) input data.
	InputRaw Local = 0

	// InputLen refers to the local variable containing the length of the raw input.
	InputLen Local = 1

	// Input refers to the local variable containing the address of the deserialized
	// input value.
	Input Local = 2
)

type LoopStmt

type LoopStmt struct {
	Source Local
	Key    Local
	Value  Local
	Cond   Local
	Block  Block
}

LoopStmt represents a loop operation on a composite value. The source of a LoopStmt may be a scalar in which case the statement will be undefined.

type MakeBooleanStmt

type MakeBooleanStmt struct {
	Value  bool
	Target Local
}

MakeBooleanStmt constructs a local variable that refers to a boolean value.

type MakeNumberIntStmt

type MakeNumberIntStmt struct {
	Value  int64
	Target Local
}

MakeNumberIntStmt constructs a local variable that refers to an integer value.

type MakeStringStmt

type MakeStringStmt struct {
	Index  int
	Target Local
}

MakeStringStmt constructs a local variable that refers to a string constant.

type NotEqualStmt

type NotEqualStmt struct {
	A Local
	B Local
}

NotEqualStmt represents a != check of two local variables.

type NullConst

type NullConst struct{}

NullConst represents a null value.

type Plan

type Plan struct {
	Blocks []Block
}

Plan represents an ordered series of blocks to execute. All plans contain a final block that returns indicating the plan result was undefined. Plan execution stops when a block returns a value. Blocks are executed in-order.

func (Plan) String

func (a Plan) String() string

type Policy

type Policy struct {
	Static Static
	Plan   Plan
}

Policy represents a planned policy query.

func (Policy) String

func (a Policy) String() string

type ReturnStmt

type ReturnStmt struct {
	Code int32 // 32-bit integer for compatibility with languages like JavaScript.
}

ReturnStmt represents a return statement. Return statements halt execution of a plan with the given code.

type Static

type Static struct {
	Strings []StringConst
}

Static represents a static data segment that is indexed into by the policy.

func (Static) String

func (a Static) String() string

type Stmt

type Stmt interface {
}

Stmt represents an operation (e.g., comparison, loop, dot, etc.) to execute.

type StringConst

type StringConst struct {
	Value string
}

StringConst represents a string value.

type Visitor

type Visitor interface {
	Before(x interface{})
	Visit(x interface{}) (Visitor, error)
	After(x interface{})
}

Visitor defines the interface for visiting IR nodes.