package ir

import "github.com/open-policy-agent/opa/internal/ir"

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

Functions

func Pretty 

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

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 ArrayAppendStmt 

type ArrayAppendStmt struct {
	Value LocalOrConst
	Array Local

	Location
}

ArrayAppendStmt represents a dynamic append operation of a value onto an array.

type AssignIntStmt 

type AssignIntStmt struct {
	Value  int64
	Target Local

	Location
}

AssignIntStmt represents an assignment of an integer value to a local variable.

type AssignVarOnceStmt 

type AssignVarOnceStmt struct {
	Target Local
	Source LocalOrConst

	Location
}

AssignVarOnceStmt represents an assignment of one local variable to another. If the target is defined, execution aborts with a conflict error.

TODO(tsandall): is there a better name for this?

type AssignVarStmt 

type AssignVarStmt struct {
	Source LocalOrConst
	Target Local

	Location
}

AssignVarStmt represents an assignment of one local variable to another.

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 BlockStmt 

type BlockStmt struct {
	Blocks []*Block

	Location
}

BlockStmt represents a nested block. Nested blocks and break statements can be used to short-circuit execution.

func (*BlockStmt) String 

func (a *BlockStmt) String() string

type Bool 

type Bool bool

Bool represents a constant boolean.

func (Bool) String 

func (b Bool) String() string

type BooleanConst 

type BooleanConst struct {
	Value bool
}

BooleanConst represents a boolean value.

type BreakStmt 

type BreakStmt struct {
	Index uint32

	Location
}

BreakStmt represents a jump out of the current block. The index specifies how many blocks to jump starting from zero (the current block). Execution will continue from the end of the block that is jumped to.

type BuiltinFunc 

type BuiltinFunc struct {
	Name string
}

BuiltinFunc represents a built-in function that may be required by the policy.

type CallDynamicStmt 

type CallDynamicStmt struct {
	Args   []Local
	Result Local
	Path   []LocalOrConst

	Location
}

CallDynamicStmt represents an indirect (data) function call. The result should be stored in the result local.

type CallStmt 

type CallStmt struct {
	Func   string
	Args   []LocalOrConst
	Result Local

	Location
}

CallStmt represents a named function call. The result should be stored in the result local.

type Const 

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

Const represents a constant value from the policy.

type DotStmt 

type DotStmt struct {
	Source LocalOrConst
	Key    LocalOrConst
	Target Local

	Location
}

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 LocalOrConst
	B LocalOrConst

	Location
}

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

type FloatConst 

type FloatConst struct {
	Value float64
}

FloatConst represents a floating-point constant.

type Func 

type Func struct {
	Name   string
	Params []Local
	Return Local
	Blocks []*Block // TODO(tsandall): should this be a plan?
	Path   []string // optional: if non-nil, include in data function tree
}

Func represents a named plan (function) that can be invoked. Functions accept one or more parameters and return a value. By convention, the input document and data documents are always passed as the first and second arguments (respectively).

func (*Func) String 

func (a *Func) String() string

type Funcs 

type Funcs struct {
	Funcs []*Func
}

Funcs represents a collection of planned functions to include in the policy.

func (*Funcs) String 

func (a *Funcs) String() string

type IntConst 

type IntConst struct {
	Value int64
}

IntConst represents an integer constant.

type IsArrayStmt 

type IsArrayStmt struct {
	Source LocalOrConst

	Location
}

IsArrayStmt represents a dynamic type check on a local variable.

type IsDefinedStmt 

type IsDefinedStmt struct {
	Source Local

	Location
}

IsDefinedStmt represents a check of whether a local variable is defined.

type IsObjectStmt 

type IsObjectStmt struct {
	Source LocalOrConst

	Location
}

IsObjectStmt represents a dynamic type check on a local variable.

type IsUndefinedStmt 

type IsUndefinedStmt struct {
	Source Local

	Location
}

IsUndefinedStmt represents a check of whether local variable is undefined.

type LenStmt 

type LenStmt struct {
	Source LocalOrConst
	Target Local

	Location
}

LenStmt represents a length() operation on a local variable. The result is stored in the target local variable.

type Local 

type Local int

Local represents a plan-scoped variable.

TODO(tsandall): should this be int32 for safety? 

const (
	// Input is the local variable that refers to the global input document.
	Input Local = iota

	// Data is the local variable that refers to the global data document.
	Data

	// Unused is the free local variable that can be allocated in a plan.
	Unused
)

func (Local) String 

func (l Local) String() string

type LocalOrConst 

type LocalOrConst interface {
	fmt.Stringer
	// contains filtered or unexported methods
}

LocalOrConst is a tagged union of the two types, Local and StringIndex.

type Location 

type Location struct {
	Index    int // filename string constant index
	Col, Row int
	// contains filtered or unexported fields
}

Location records the filen index, and the row and column inside that file that a statement can be connected to.

func (*Location) GetLocation 

func (l *Location) GetLocation() *Location

GetLocation returns a Stmt's Location.

func (*Location) SetLocation 

func (l *Location) SetLocation(index, row, col int, file, text string)

SetLocation sets the Location for a given Stmt.

type MakeArrayStmt 

type MakeArrayStmt struct {
	Capacity int32
	Target   Local

	Location
}

MakeArrayStmt constructs a local variable that refers to an array value.

type MakeNullStmt 

type MakeNullStmt struct {
	Target Local

	Location
}

MakeNullStmt constructs a local variable that refers to a null value.

type MakeNumberFloatStmt 

type MakeNumberFloatStmt struct {
	Value  float64
	Target Local

	Location
}

MakeNumberFloatStmt constructs a local variable that refers to a floating-point number value.

type MakeNumberIntStmt 

type MakeNumberIntStmt struct {
	Value  int64
	Target Local

	Location
}

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

type MakeNumberRefStmt 

type MakeNumberRefStmt struct {
	Index  int
	Target Local

	Location
}

MakeNumberRefStmt constructs a local variable that refers to a number stored as a string.

type MakeObjectStmt 

type MakeObjectStmt struct {
	Target Local

	Location
}

MakeObjectStmt constructs a local variable that refers to an object value.

type MakeSetStmt 

type MakeSetStmt struct {
	Target Local

	Location
}

MakeSetStmt constructs a local variable that refers to a set value.

type NopStmt 

type NopStmt struct {
	Location
}

NopStmt adds a nop instruction. Useful during development and debugging only.

type NotEqualStmt 

type NotEqualStmt struct {
	A LocalOrConst
	B LocalOrConst

	Location
}

NotEqualStmt represents a != check of two local variables.

type NotStmt 

type NotStmt struct {
	Block *Block

	Location
}

NotStmt represents a negated statement.

type NullConst 

type NullConst struct{}

NullConst represents a null value.

type ObjectInsertOnceStmt 

type ObjectInsertOnceStmt struct {
	Key    LocalOrConst
	Value  LocalOrConst
	Object Local

	Location
}

ObjectInsertOnceStmt represents a dynamic insert operation of a key/value pair into an object. If the key already exists and the value differs, execution aborts with a conflict error.

type ObjectInsertStmt 

type ObjectInsertStmt struct {
	Key    LocalOrConst
	Value  LocalOrConst
	Object Local

	Location
}

ObjectInsertStmt represents a dynamic insert operation of a key/value pair into an object.

type ObjectMergeStmt 

type ObjectMergeStmt struct {
	A      Local
	B      Local
	Target Local

	Location
}

ObjectMergeStmt performs a recursive merge of two object values. If either of the locals refer to non-object values this operation will abort with a conflict error. Overlapping object keys are merged recursively.

type Plan 

type Plan struct {
	Name   string
	Blocks []*Block
}

Plan represents an ordered series of blocks to execute. Plan execution stops when a return statement is reached. Blocks are executed in-order.

func (*Plan) String 

func (a *Plan) String() string

type Plans 

type Plans struct {
	Plans []*Plan
}

Plans represents a collection of named query plans to expose in the policy.

type Policy 

type Policy struct {
	Static *Static
	Plans  *Plans
	Funcs  *Funcs
}

Policy represents a planned policy query.

func (*Policy) String 

func (a *Policy) String() string

type ResetLocalStmt 

type ResetLocalStmt struct {
	Target Local

	Location
}

ResetLocalStmt resets a local variable to 0.

type ResultSetAdd 

type ResultSetAdd struct {
	Value Local

	Location
}

ResultSetAdd adds a value into the result set returned by the query plan.

type ReturnLocalStmt 

type ReturnLocalStmt struct {
	Source Local

	Location
}

ReturnLocalStmt represents a return statement that yields a local value.

type ScanStmt 

type ScanStmt struct {
	Source Local
	Key    Local
	Value  Local
	Block  *Block

	Location
}

ScanStmt represents a linear scan over a composite value. The source may be a scalar in which case the block will never execute.

type SetAddStmt 

type SetAddStmt struct {
	Value LocalOrConst
	Set   Local

	Location
}

SetAddStmt represents a dynamic add operation of an element into a set.

type Static 

type Static struct {
	Strings      []*StringConst
	BuiltinFuncs []*BuiltinFunc
	Files        []*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 {
	// contains filtered or unexported methods
}

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 StringIndex 

type StringIndex int

StringIndex represents the index into the plan's list of constant strings of a constant string.

func (StringIndex) String 

func (s StringIndex) String() string

type Visitor 

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

Visitor defines the interface for visiting IR nodes.

type WithStmt 

type WithStmt struct {
	Local Local
	Path  []int
	Value LocalOrConst
	Block *Block

	Location
}

WithStmt replaces the Local or a portion of the document referred to by the Local with the Value and executes the contained block. If the Path is non-empty, the Value is upserted into the Local. If the intermediate nodes in the Local referred to by the Path do not exist, they will be created. When the WithStmt finishes the Local is reset to it's original value.

Source Files

ir.go pretty.go walk.go

Version
v0.29.2
Published
May 28, 2021
Platform
js/wasm
Imports
3 packages
Last checked
46 seconds ago –

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