internal

Documentation

Overview

Package internal exposes some cue internals to other packages.

A better name for this package would be technicaldebt.

Index

• Constants
• Variables
• func DecorateError(info error, err errors.Error) errors.Error
• func EmbedStruct(s *ast.StructLit) *ast.EmbedDecl
• func FileComment(f *ast.File) *ast.CommentGroup
• func GenPath(root string) string
• func Imports(f *ast.File) (a []ast.Decl)
• func IsBulkField(d ast.Decl) bool
• func IsDef(s string) bool
• func IsDefOrHidden(s string) bool
• func IsDefinition(label ast.Label) bool
• func IsEllipsis(x ast.Decl) bool
• func IsHidden(s string) bool
• func IsRegularField(f *ast.Field) bool
• func ListEllipsis(n *ast.ListLit) (elts []ast.Expr, e *ast.Ellipsis)
• func NewAttr(name, str string) *ast.Attribute
• func NewComment(isDoc bool, s string) *ast.CommentGroup
• func PackageInfo(f *ast.File) (p *ast.Package, name string, tok token.Pos)
• func SetPackage(f *ast.File, name string, overwrite bool)
• func ToExpr(n ast.Node) ast.Expr
• func ToFile(n ast.Node) *ast.File
• func ToStruct(f *ast.File) *ast.StructLit
• type Attr
  • func NewNonExisting(key string) Attr
  • func ParseAttrBody(pos token.Pos, s string) (a Attr)
  • func (a *Attr) Flag(pos int, key string) (bool, error)
  • func (a *Attr) Int(pos int) (int64, error)
  • func (a *Attr) Lookup(pos int, key string) (val string, found bool, err error)
  • func (a *Attr) String(pos int) (string, error)
• type Decimal

Constants

const MaxDepth = 20

MaxDepth indicates the maximum evaluation depth. This is there to break cycles in the absence of cycle detection.

It is registered in a central place to make it easy to find all spots where cycles are broken in this brute-force manner.

TODO(eval): have cycle detection.

Variables

var BaseContext = apd.BaseContext.WithPrecision(24)

BaseContext is used as CUEs default context for arbitrary-precision decimals

var CheckAndForkRuntime func(runtime, value interface{}) interface{}

CheckAndForkRuntime checks that value is created using runtime, panicking if it does not, and returns a forked runtime that will discard additional keys.

var DebugStr func(x interface{}) string

DebugStr prints a syntax node.

var ErrIncomplete = errors.New("incomplete value")

ErrIncomplete can be used by builtins to signal the evaluation was incomplete.

var ErrInexact = errors.New("inexact subsumption")

var EvalExpr func(value, expr interface{}) (result interface{})

EvalExpr evaluates an expression within an existing struct value. Identifiers only resolve to values defined within the struct.

Expressions may refer to builtin packages if they can be uniquely identified

Both value and result are of type cue.Value, but are an interface to prevent cyclic dependencies.

TODO: extract interface

var FromGoType func(instance, x interface{}) interface{}

FromGoType converts an arbitrary Go type to the corresponding CUE value. instance must be of type *cue.Instance. The returned value is a cue.Value, which the caller must cast to.

var FromGoValue func(instance, x interface{}, allowDefault bool) interface{}

FromGoValue converts an arbitrary Go value to the corresponding CUE value. instance must be of type *cue.Instance. The returned value is a cue.Value, which the caller must cast to.

var GetRuntime func(instance interface{}) interface{}

GetRuntime reports the runtime for an Instance or Value.

var MakeInstance func(value interface{}) (instance interface{})

MakeInstance makes a new instance from a value.

var UnifyBuiltin func(v interface{}, kind string) interface{}

UnifyBuiltin returns the given Value unified with the given builtin template.

Functions

func DecorateError

func DecorateError(info error, err errors.Error) errors.Error

func EmbedStruct

func EmbedStruct(s *ast.StructLit) *ast.EmbedDecl

func FileComment

func FileComment(f *ast.File) *ast.CommentGroup

func GenPath

func GenPath(root string) string

GenPath reports the directory in which to store generated files.

func Imports

func Imports(f *ast.File) (a []ast.Decl)

func IsBulkField

func IsBulkField(d ast.Decl) bool

func IsDef

func IsDef(s string) bool

func IsDefOrHidden

func IsDefOrHidden(s string) bool

func IsDefinition

func IsDefinition(label ast.Label) bool

func IsEllipsis

func IsEllipsis(x ast.Decl) bool

IsEllipsis reports whether the declaration can be represented as an ellipsis.

func IsHidden

func IsHidden(s string) bool

func IsRegularField

func IsRegularField(f *ast.Field) bool

func ListEllipsis

func ListEllipsis(n *ast.ListLit) (elts []ast.Expr, e *ast.Ellipsis)

ListEllipsis reports the list type and remaining elements of a list. If we ever relax the usage of ellipsis, this function will likely change. Using this function will ensure keeping correct behavior or causing a compiler failure.

func NewAttr

func NewAttr(name, str string) *ast.Attribute

func NewComment

func NewComment(isDoc bool, s string) *ast.CommentGroup

NewComment creates a new CommentGroup from the given text. Each line is prefixed with "//" and the last newline is removed. Useful for ASTs generated by code other than the CUE parser.

func PackageInfo

func PackageInfo(f *ast.File) (p *ast.Package, name string, tok token.Pos)

func SetPackage

func SetPackage(f *ast.File, name string, overwrite bool)

func ToExpr

func ToExpr(n ast.Node) ast.Expr

ToExpr converts a node to an expression. If it is a file, it will return it as a struct. If is an expression, it will return it as is. Otherwise it panics.

func ToFile

func ToFile(n ast.Node) *ast.File

ToFile converts an expression to a file.

Adjusts the spacing of x when needed.

func ToStruct

func ToStruct(f *ast.File) *ast.StructLit

ToStruct gets the non-preamble declarations of a file and puts them in a struct.

Types

type Attr

type Attr struct {
	Fields []keyValue
	Err    error
}

Attr holds positional information for a single Attr.

func NewNonExisting

func NewNonExisting(key string) Attr

NewNonExisting creates a non-existing attribute.

func ParseAttrBody

func ParseAttrBody(pos token.Pos, s string) (a Attr)

func (*Attr) Flag

func (a *Attr) Flag(pos int, key string) (bool, error)

Flag reports whether an entry with the given name exists at position pos or onwards or an error if the attribute is invalid or if the first pos-1 entries are not defined.

func (*Attr) Int

func (a *Attr) Int(pos int) (int64, error)

Int reports the integer at the given position or an error if the attribute is invalid, the position does not exist, or the value at the given position is not an integer.

func (*Attr) Lookup

func (a *Attr) Lookup(pos int, key string) (val string, found bool, err error)

Lookup searches for an entry of the form key=value from position pos onwards and reports the value if found. It reports an error if the attribute is invalid or if the first pos-1 entries are not defined.

func (*Attr) String

func (a *Attr) String(pos int) (string, error)

String reports the possibly empty string value at the given position or an error the attribute is invalid or if the position does not exist.

type Decimal

type Decimal = apd.Decimal

A Decimal is an arbitrary-precision binary-coded decimal number.

Right now Decimal is aliased to apd.Decimal. This may change in the future.