eval

package
v0.0.0-...-dde8c00 Latest Latest
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 Go to latest Published: Jul 10, 2017 License: BSD-2-Clause Imports: 34 Imported by: 0

Documentation

Overview

Package eval handles evaluation of nodes and consists the runtime of the shell.

Index

Constants

View Source 
const FnPrefix = "&"

FnPrefix is the prefix for the variable names of functions. Defining a function "foo" is equivalent to setting a variable named FnPrefix + "foo".

View Source 
const (
	NoPretty = util.MinInt
)

Variables

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var (
	ErrArgs              = errors.New("args error")
	ErrInput             = errors.New("input error")
	ErrStoreNotConnected = errors.New("store not connected")
	ErrNoMatchingDir     = errors.New("no matching directory")
	ErrNotInSameGroup    = errors.New("not in the same process group")
)

Errors thrown by builtins.

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var (
	ErrBadGlobPattern          = errors.New("bad GlobPattern; elvish bug")
	ErrCannotDetermineUsername = errors.New("cannot determine user name from glob pattern")
)

Errors thrown when globbing.

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var (
	ErrCanOnlyAssignList          = errors.New("can only assign compatible values")
	ErrPathMustBeString           = errors.New("path must be string")
	ErrPathCannotContainColonZero = errors.New(`path cannot contain colon or \0`)
)

Errors

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var (
	ErrExternalCmdOpts = errors.New("external commands don't accept elvish options")
	ErrCdNoArg         = errors.New("implicit cd accepts no arguments")
)
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var (
	ErrMustFollowWildcard   = errors.New("must follow wildcard")
	ErrModifierMustBeString = errors.New("modifier must be string")
	ErrWildcardNoMatch      = errors.New("wildcard has no match")
)
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var (
	// ErrNeedIntIndex    = errors.New("need integer index")
	ErrBadIndex        = errors.New("bad index")
	ErrIndexOutOfRange = errors.New("index out of range")
)

Error definitions.

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var (
	// ClosedChan is a closed channel, suitable for use as placeholder channel input.
	ClosedChan = make(chan Value)
	// BlackholeChan is channel writes onto which disappear, suitable for use as
	// placeholder channel output.
	BlackholeChan = make(chan Value)
	// DevNull is /dev/null.
	DevNull *os.File
	// DevNullClosedInput is a port made up from DevNull and ClosedChan,
	// suitable as placeholder input port.
	DevNullClosedChan *Port
)
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var (
	ErrNoArgAccepted = errors.New("no argument accepted")
	ErrNoOptAccepted = errors.New("no option accepted")
)
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var (
	NoArgs = []Value{}
	NoOpts = map[string]Value{}
)
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var ErrArityMismatch = errors.New("arity mismatch")

ErrArityMismatch is thrown by a closure when the number of arguments the user supplies does not match with what is required.

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var ErrBadBase = errors.New("bad base")

ErrBadBase is thrown by the "base" builtin if the base is smaller than 2 or greater than 36.

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var ErrDaemonOffline = errors.New("daemon is offline")
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var (
	ErrIndexMustBeString = errors.New("index must be string")
)
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var ErrInterrupted = errors.New("interrupted")
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var ErrMoreThanOneRest = errors.New("more than one @ lvalue")
View Source 
var ErrNoDataDir = errors.New("There is no data directory")

ErrNoDataDir is thrown by the "use" special form when there is no data directory.

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var (
	ErrOnlyStrOrRat = errors.New("only str or rat may be converted to rat")
)

Error definitions.

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var (
	ErrRoCannotBeSet = errors.New("read-only variable; cannot be set")
)
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var ErrStoreUnconnected = errors.New("store unconnected")

ErrStoreUnconnected is thrown by ResolveVar when a shared: variable needs to be resolved but the store is not connected.

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var (
	ErrValueMustBeString = errors.New("index must be string")
)
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var IsBuiltinSpecial = map[string]bool{}

IsBuiltinSpecial is the set of all names of builtin special forms. It is intended for external consumption, e.g. the syntax highlighter.

View Source 
var OK = &Exception{}

OK is a pointer to the zero value of Exception, representing the absence of exception.

Functions

func AddBuiltinFns 

func AddBuiltinFns(ns Namespace, fns ...*BuiltinFn)

AddBuiltinFns adds builtin functions to a namespace.

func Chdir 

func Chdir(path string, daemon *api.Client) error

Chdir changes the current directory. On success it also updates the PWD environment variable and records the new directory in the directory history. It returns nil as long as the directory changing part succeeds.

func ClosePorts 

func ClosePorts(ports []*Port)

ClosePorts closes a list of Ports.

func ComposeExceptionsFromPipeline 

func ComposeExceptionsFromPipeline(excs []*Exception) error

ComposeExceptionsFromPipeline takes a slice of Exception pointers and composes a suitable error. If all elements of the slice are either nil or OK, a nil is returned. If there is exactly non-nil non-OK Exception, it is returned. Otherwise, a PipelineError built from the slice is returned, with nil items turned into OK's for easier access from elvishscript.

func DeepEq 

func DeepEq(a, b Value) bool

DeepEq compares two Value's deeply.

func MakeVariableName 

func MakeVariableName(explode bool, ns string, name string) string

func NewExternalCmdExit 

func NewExternalCmdExit(name string, ws syscall.WaitStatus, pid int) error

func ParseAndFixListIndex 

func ParseAndFixListIndex(s string, n int) (bool, int, int)

ParseAndFixListIndex parses a list index and returns whether the index is a slice and "real" (-1 becomes n-1) indicies. It throws errors when the index is invalid or out of range.

func ParseAndFixVariable 

func ParseAndFixVariable(qname string) (explode bool, ns string, name string)

ParseAndFixVariable parses a variable name. It "fixes" $@ to $@args.

func ParseVariable 

func ParseVariable(text string) (explode bool, ns string, name string)

func ParseVariableQName 

func ParseVariableQName(qname string) (ns, name string)

func ParseVariableSplice 

func ParseVariableSplice(text string) (explode, qname string)

func ScanArgs 

func ScanArgs(s []Value, args ...interface{})

ScanArgs scans arguments into pointers to supported argument types. If the arguments cannot be scanned, an error is thrown.

func ScanArgsAndOptionalIterate 

func ScanArgsAndOptionalIterate(ec *EvalCtx, s []Value, args ...interface{}) func(func(Value))

ScanArgsAndOptionalIterate is like ScanArgs, but the argument can contain an optional iterable value at the end. The return value is a function that iterates the iterable value if it exists, or the input otherwise.

func ScanArgsVariadic 

func ScanArgsVariadic(s []Value, args ...interface{})

ScanArgsVariadic is like ScanArgs, but the last element of args should be a pointer to a slice, and the rest of arguments will be scanned into it.

func ScanOpts 

func ScanOpts(m map[string]Value, opts ...Opt)

ScanOpts scans options from a map.

func ShouldBeBool 

func ShouldBeBool(v Value) error

func ShouldBeFn 

func ShouldBeFn(v Value) error

func ShouldBeList 

func ShouldBeList(v Value) error

func ShouldBeMap 

func ShouldBeMap(v Value) error

func TakeNoArg 

func TakeNoArg(args []Value)

func TakeNoOpt 

func TakeNoOpt(opts map[string]Value)

func ToBool 

func ToBool(v Value) bool

ToBool converts a Value to bool. When the Value type implements Bool(), it is used. Otherwise it is considered true.

func ToString 

func ToString(v Value) string

ToString converts a Value to String. When the Value type implements String(), it is used. Otherwise Repr(NoPretty) is used.

func WrapStringToString 

func WrapStringToString(f func(string) string) func(*EvalCtx, []Value, map[string]Value)

func WrapStringToStringError 

func WrapStringToStringError(f func(string) (string, error)) func(*EvalCtx, []Value, map[string]Value)

Types

type Bool 

type Bool bool

Bool represents truthness.

func (Bool) Bool 

func (b Bool) Bool() bool

func (Bool) Kind 

func (Bool) Kind() string

func (Bool) Repr 

func (b Bool) Repr(int) string

type Booler 

type Booler interface {
	Bool() bool
}

Booler is anything that can be converted to a bool.

type BuiltinFn 

type BuiltinFn struct {
	Name string
	Impl func(*EvalCtx, []Value, map[string]Value)
}

BuiltinFn is a builtin function.

func (*BuiltinFn) Call 

func (b *BuiltinFn) Call(ec *EvalCtx, args []Value, opts map[string]Value)

Call calls a builtin function.

func (*BuiltinFn) Kind 

func (*BuiltinFn) Kind() string

Kind returns "fn".

func (*BuiltinFn) Repr 

func (b *BuiltinFn) Repr(int) string

Repr returns an opaque representation "<builtin xxx>".

type Callable 

type Callable interface {
	Call(ec *EvalCtx, args []Value, opts map[string]Value)
}

Callable is anything may be called on an evalCtx with a list of Value's.

type CallableValue 

type CallableValue interface {
	Value
	Callable
}

type Closure 

type Closure struct {
	ArgNames []string
	// The name for the rest argument. If empty, the function has fixed arity.
	// If equal to unnamedRestArg, the rest argument is unnamed but can be
	// accessed via $args.
	RestArg    string
	Op         Op
	Captured   map[string]Variable
	SourceName string
	Source     string
}

Closure is a closure defined in elvish script.

func (*Closure) Call 

func (c *Closure) Call(ec *EvalCtx, args []Value, opts map[string]Value)

Call calls a closure.

func (*Closure) Kind 

func (*Closure) Kind() string

Kind returns "fn".

func (*Closure) Repr 

func (c *Closure) Repr(int) string

Repr returns an opaque representation "<closure 0x23333333>".

type CompilationError 

type CompilationError struct {
	Message string
	Context util.SourceContext
}

CompilationError represents a compilation error and can pretty print it.

func (*CompilationError) Error 

func (ce *CompilationError) Error() string

func (*CompilationError) Pprint 

func (ce *CompilationError) Pprint(indent string) string

Pprint pretty-prints a compilation error.

type Editor 

type Editor interface {
	Active() bool
	ActiveMutex() *sync.Mutex
	Notify(string, ...interface{})
}

Editor is the interface that the line editor has to satisfy. It is needed so that this package does not depend on the edit package.

type EnvPathList 

type EnvPathList struct {
	sync.RWMutex
	// contains filtered or unexported fields
}

EnvPathList is a variable whose value is constructed from an environment variable by splitting at colons. Changes to it are also propagated to the corresponding environment variable. Its elements cannot contain colons or \0; attempting to put colon or \0 in its elements will result in an error.

EnvPathList implements both Value and Variable interfaces. It also satisfied ListLike.

func (*EnvPathList) Get 

func (epl *EnvPathList) Get() Value

Get returns a Value for an EnvPathList.

func (*EnvPathList) IndexOne 

func (epl *EnvPathList) IndexOne(idx Value) Value

IndexOne returns the result of one indexing operation.

func (*EnvPathList) IndexSet 

func (epl *EnvPathList) IndexSet(idx, v Value)

IndexSet sets one value in an EnvPathList.

func (*EnvPathList) Iterate 

func (epl *EnvPathList) Iterate(f func(Value) bool)

Iterate iterates an EnvPathList.

func (*EnvPathList) Kind 

func (epl *EnvPathList) Kind() string

Kind returns "list".

func (*EnvPathList) Len 

func (epl *EnvPathList) Len() int

Len returns the length of an EnvPathList.

func (*EnvPathList) Repr 

func (epl *EnvPathList) Repr(indent int) string

Repr returns the representation of an EnvPathList, as if it were an ordinary list.

func (*EnvPathList) Set 

func (epl *EnvPathList) Set(v Value)

Set sets an EnvPathList. The underlying environment variable is set.

type EvalCtx 

type EvalCtx struct {
	*Evaler
	// contains filtered or unexported fields
}

EvalCtx maintains an Evaler along with its runtime context. After creation an EvalCtx is seldom modified, and new instances are created when needed.

func NewTopEvalCtx 

func NewTopEvalCtx(ev *Evaler, name, text string, ports []*Port) *EvalCtx

NewTopEvalCtx creates a top-level evalCtx.

func (*EvalCtx) CheckInterrupts 

func (ec *EvalCtx) CheckInterrupts()

CheckInterrupts checks whether there has been an interrupt, and throws ErrInterrupted if that is the case

func (*EvalCtx) Interrupts 

func (ec *EvalCtx) Interrupts() <-chan struct{}

Interrupts returns a channel that is closed when an interrupt signal comes.

func (*EvalCtx) IterateInputs 

func (ec *EvalCtx) IterateInputs(f func(Value))

IterateInputs calls the passed function for each input element.

func (*EvalCtx) OutputChan 

func (ec *EvalCtx) OutputChan() chan<- Value

OutputChan returns a channel onto which output can be written.

func (*EvalCtx) OutputFile 

func (ec *EvalCtx) OutputFile() *os.File

OutputFile returns a file onto which output can be written.

func (*EvalCtx) PCall 

func (ec *EvalCtx) PCall(f Callable, args []Value, opts map[string]Value) (err error)

func (*EvalCtx) PCaptureOutput 

func (ec *EvalCtx) PCaptureOutput(f Callable, args []Value, opts map[string]Value) (vs []Value, err error)

func (*EvalCtx) PEval 

func (ec *EvalCtx) PEval(op Op) (err error)

PEval evaluates an op in a protected environment so that calls to errorf are wrapped in an Error.

func (*EvalCtx) ResolveVar 

func (ec *EvalCtx) ResolveVar(ns, name string) Variable

ResolveVar resolves a variable. When the variable cannot be found, nil is returned.

type Evaler 

type Evaler struct {
	Builtin Namespace
	Global  Namespace
	Modules map[string]Namespace
	Daemon  *api.Client
	ToSpawn *daemon.Daemon
	Editor  Editor
	DataDir string
	// contains filtered or unexported fields
}

Evaler is used to evaluate elvish sources. It maintains runtime context shared among all evalCtx instances.

func NewEvaler 

func NewEvaler(daemon *api.Client, toSpawn *daemon.Daemon,
	dataDir string, extraModules map[string]Namespace) *Evaler

NewEvaler creates a new Evaler.

func (*Evaler) Compile 

func (ev *Evaler) Compile(n *parse.Chunk, name, text string) (Op, error)

Compile compiles elvish code in the global scope. If the error is not nil, it always has type CompilationError.

func (*Evaler) EachExternal 

func (ev *Evaler) EachExternal(f func(string))

EachExternal calls f for each name that can resolve to an external command.

func (*Evaler) Eval 

func (ev *Evaler) Eval(op Op, name, text string) error

Eval sets up the Evaler with standard ports and evaluates an Op. The supplied name and text are used in diagnostic messages.

func (*Evaler) EvalWithPorts 

func (ev *Evaler) EvalWithPorts(ports []*Port, op Op, name, text string) error

EvalWithPorts sets up the Evaler with the given ports and evaluates an Op. The supplied name and text are used in diagnostic messages.

func (*Evaler) Search 

func (ev *Evaler) Search(exe string) (string, error)

Search tries to resolve an external command and return the full (possibly relative) path.

func (*Evaler) Source 

func (ev *Evaler) Source(fname string) error

Source evaluates the content of a file.

func (*Evaler) SourceText 

func (ev *Evaler) SourceText(name, src string) error

SourceText evaluates a chunk of elvish source.

type Exception 

type Exception struct {
	Cause     error
	Traceback *util.SourceContext
}

Exception represents an elvish exception. It is both a Value accessible to elvishscript, and the type of error returned by public facing evaluation methods like (*Evaler)PEval.

func (*Exception) Bool 

func (exc *Exception) Bool() bool

func (*Exception) Error 

func (exc *Exception) Error() string

func (*Exception) Kind 

func (exc *Exception) Kind() string

func (*Exception) Pprint 

func (exc *Exception) Pprint(indent string) string

func (*Exception) Repr 

func (exc *Exception) Repr(indent int) string

type ExternalCmd 

type ExternalCmd struct {
	Name string
}

ExternalCmd is an external command.

func (ExternalCmd) Call 

func (e ExternalCmd) Call(ec *EvalCtx, argVals []Value, opts map[string]Value)

Call calls an external command.

func (ExternalCmd) Kind 

func (ExternalCmd) Kind() string

func (ExternalCmd) Repr 

func (e ExternalCmd) Repr(int) string

type ExternalCmdExit 

type ExternalCmdExit struct {
	syscall.WaitStatus
	CmdName string
	Pid     int
}

ExternalCmdExit contains the exit status of external commands. If the command was stopped rather than terminated, the Pid field contains the pid of the process.

func FakeExternalCmdExit 

func FakeExternalCmdExit(name string, exit int, sig syscall.Signal) ExternalCmdExit

func (ExternalCmdExit) Error 

func (exit ExternalCmdExit) Error() string

type File 

type File struct {
	// contains filtered or unexported fields
}

func (File) Kind 

func (File) Kind() string

func (File) Repr 

func (f File) Repr(int) string

type Flow 

type Flow uint

Flow is a special type of error used for control flows. 

const (
	Return Flow = iota
	Break
	Continue
)

Control flows.

func (Flow) Error 

func (f Flow) Error() string

func (Flow) Pprint 

func (f Flow) Pprint(string) string

func (Flow) Repr 

func (f Flow) Repr(int) string

type GlobFlag 

type GlobFlag uint
const (
	NoMatchOK GlobFlag = 1 << iota
)

func (GlobFlag) Has 

func (f GlobFlag) Has(g GlobFlag) bool

type GlobPattern 

type GlobPattern struct {
	glob.Pattern
	Flags GlobFlag
	Buts  []string
}

GlobPattern is en ephemeral Value generated when evaluating tilde and wildcards.

func (GlobPattern) Index 

func (gp GlobPattern) Index(modifiers []Value) []Value

func (GlobPattern) Kind 

func (GlobPattern) Kind() string

func (GlobPattern) Repr 

func (gp GlobPattern) Repr(int) string

type HasKeyer 

type HasKeyer interface {
	HasKey(k Value) bool
}

type IndexOneer 

type IndexOneer interface {
	IndexOne(idx Value) Value
}

IndexOneer is anything that can be indexed by one Value and yields one Value.

type IndexOneerIndexer 

type IndexOneerIndexer struct {
	IndexOneer
}

IndexOneerIndexer adapts an IndexOneer to an Indexer by calling all the indicies on the IndexOner and collect the results.

func (IndexOneerIndexer) Index 

func (ioi IndexOneerIndexer) Index(vs []Value) []Value

type IndexSetter 

type IndexSetter interface {
	IndexOneer
	IndexSet(idx Value, v Value)
}

IndexSetter is a Value whose elements can be get as well as set.

type Indexer 

type Indexer interface {
	Index(idx []Value) []Value
}

Indexer is anything that can be indexed by Values and yields Values.

type Iterable 

type Iterable interface {
	Iterate(func(Value) bool)
}

Iterable is anything that can be iterated.

type IterableValue 

type IterableValue interface {
	Iterable
	Value
}

type IterateKeyer 

type IterateKeyer interface {
	IterateKey(func(Value) bool)
}

IterateKeyer is anything with keys that can be iterated.

type Kinder 

type Kinder interface {
	Kind() string
}

Kinder is anything with kind string.

type LValuesOp 

type LValuesOp struct {
	Func       LValuesOpFunc
	Begin, End int
}

LValuesOp is an operation on an EvalCtx that produce Variable's.

func (LValuesOp) Exec 

func (op LValuesOp) Exec(ec *EvalCtx) []Variable

Exec executes an LValuesOp, producing Variable's.

type LValuesOpFunc 

type LValuesOpFunc func(*EvalCtx) []Variable

LValuesOpFunc is the body of an LValuesOp.

type Lener 

type Lener interface {
	Len() int
}

Lener is anything with a length.

type List 

type List struct {
	// contains filtered or unexported fields
}

List is a list of Value's.

func NewList 

func NewList(vs ...Value) List

NewList creates a new List.

func NewListFromVector 

func NewListFromVector(vec vector.Vector) List

func (List) IndexOne 

func (l List) IndexOne(idx Value) Value

func (List) Iterate 

func (l List) Iterate(f func(Value) bool)

func (List) Kind 

func (List) Kind() string

func (List) Len 

func (l List) Len() int

func (List) MarshalJSON 

func (l List) MarshalJSON() ([]byte, error)

func (List) Repr 

func (l List) Repr(indent int) string

type ListLike 

type ListLike interface {
	Lener
	Iterable
	IndexOneer
}

type ListReprBuilder 

type ListReprBuilder struct {
	Indent int
	// contains filtered or unexported fields
}

ListReprBuilder helps to build Repr of list-like Values.

func (*ListReprBuilder) String 

func (b *ListReprBuilder) String() string

func (*ListReprBuilder) WriteElem 

func (b *ListReprBuilder) WriteElem(v string)

type Map 

type Map struct {
	// contains filtered or unexported fields
}

Map is a map from string to Value.

func NewMap 

func NewMap(inner map[Value]Value) Map

NewMap creates a new Map.

func (Map) HasKey 

func (m Map) HasKey(k Value) bool

func (Map) IndexOne 

func (m Map) IndexOne(idx Value) Value

func (Map) IndexSet 

func (m Map) IndexSet(idx Value, v Value)

func (Map) IterateKey 

func (m Map) IterateKey(f func(Value) bool)

func (Map) Kind 

func (Map) Kind() string

func (Map) Len 

func (m Map) Len() int

func (Map) MarshalJSON 

func (m Map) MarshalJSON() ([]byte, error)

func (Map) Repr 

func (m Map) Repr(indent int) string

type MapLike 

type MapLike interface {
	Lener
	IndexOneer
	HasKeyer
	IterateKeyer
}

type MapReprBuilder 

type MapReprBuilder struct {
	ListReprBuilder
}

MapReprBuilder helps building the Repr of a Map. It is also useful for implementing other Map-like values. The zero value of a MapReprBuilder is ready to use.

func (*MapReprBuilder) String 

func (b *MapReprBuilder) String() string

func (*MapReprBuilder) WritePair 

func (b *MapReprBuilder) WritePair(k string, indent int, v string)

type MapStringString 

type MapStringString map[string]string

MapStringString implements MapLike for map[string]string.

func (MapStringString) HasKey 

func (m MapStringString) HasKey(idx Value) bool

func (MapStringString) IndexOne 

func (m MapStringString) IndexOne(idx Value) Value

func (MapStringString) IndexSet 

func (m MapStringString) IndexSet(idx Value, val Value)

func (MapStringString) IterateKey 

func (m MapStringString) IterateKey(f func(Value) bool)

func (MapStringString) Kind 

func (MapStringString) Kind() string

func (MapStringString) Len 

func (m MapStringString) Len() int

func (MapStringString) Repr 

func (m MapStringString) Repr(indent int) string

type Namespace 

type Namespace map[string]Variable

Namespace is a map from name to variables.

type Op 

type Op struct {
	Func       OpFunc
	Begin, End int
}

Op is an operation on an EvalCtx.

func (Op) Exec 

func (op Op) Exec(ec *EvalCtx)

Exec executes an Op.

type OpFunc 

type OpFunc func(*EvalCtx)

OpFunc is the body of an Op.

type Opt 

type Opt struct {
	Name    string
	Ptr     interface{}
	Default Value
}

Opt is a data structure for an option that is intended to be used in ScanOpts.

type Pipe 

type Pipe struct {
	// contains filtered or unexported fields
}

func (Pipe) Kind 

func (Pipe) Kind() string

func (Pipe) Repr 

func (p Pipe) Repr(int) string

type PipelineError 

type PipelineError struct {
	Errors []*Exception
}

PipelineError represents the errors of pipelines, in which multiple commands may error.

func (PipelineError) Error 

func (pe PipelineError) Error() string

func (PipelineError) Repr 

func (pe PipelineError) Repr(indent int) string

type Port 

type Port struct {
	File      *os.File
	Chan      chan Value
	CloseFile bool
	CloseChan bool
}

Port conveys data stream. It always consists of a byte band and a channel band.

func (*Port) Close 

func (p *Port) Close()

Close closes a Port.

func (*Port) Fork 

func (p *Port) Fork() *Port

Fork returns a copy of a Port with the Close* flags unset.

type PwdVariable 

type PwdVariable struct {
	// contains filtered or unexported fields
}

PwdVariable is a variable whose value always reflects the current working directory. Setting it changes the current working directory.

func (PwdVariable) Get 

func (PwdVariable) Get() Value

func (PwdVariable) Set 

func (pwd PwdVariable) Set(v Value)

type Rat 

type Rat struct {
	// contains filtered or unexported fields
}

Rat is a rational number.

func ToRat 

func ToRat(v Value) (Rat, error)

ToRat converts a Value to rat. A str can be converted to a rat if it can be parsed. A rat is returned as-is. Other types of values cannot be converted.

func (Rat) Kind 

func (Rat) Kind() string

func (Rat) Repr 

func (r Rat) Repr(int) string

func (Rat) String 

func (r Rat) String() string

type Reprer 

type Reprer interface {
	// Repr returns a string that represents a Value. The string either be a
	// literal of that Value that is preferably deep-equal to it (like `[a b c]`
	// for a list), or a string enclosed in "<>" containing the kind and
	// identity of the Value(like `<fn 0xdeadcafe>`).
	//
	// If indent is at least 0, it should be pretty-printed with the current
	// indentation level of indent; the indent of the first line has already
	// been written and shall not be written in Repr. The returned string
	// should never contain a trailing newline.
	Repr(indent int) string
}

Reprer is anything with a Repr method.

type String 

type String string

String is just a string.

func (String) Call 

func (s String) Call(ec *EvalCtx, args []Value, opts map[string]Value)

Call resolves a command name to either a Fn variable or external command and calls it.

func (String) IndexOne 

func (s String) IndexOne(idx Value) Value

func (String) Iterate 

func (s String) Iterate(f func(v Value) bool)

func (String) Kind 

func (String) Kind() string

func (String) Len 

func (s String) Len() int

func (String) Repr 

func (s String) Repr(int) string

func (String) String 

func (s String) String() string

type Stringer 

type Stringer interface {
	String() string
}

Stringer is anything that can be converted to a string.

type Struct 

type Struct struct {
	FieldNames []string
	Fields     []Variable
}

Struct is like a Map with fixed keys.

func (*Struct) HasKey 

func (s *Struct) HasKey(k Value) bool

func (*Struct) IndexOne 

func (s *Struct) IndexOne(idx Value) Value

func (*Struct) IndexSet 

func (s *Struct) IndexSet(idx Value, v Value)

func (*Struct) IterateKey 

func (s *Struct) IterateKey(f func(Value) bool)

func (*Struct) Kind 

func (*Struct) Kind() string

func (*Struct) Len 

func (s *Struct) Len() int

func (*Struct) Repr 

func (s *Struct) Repr(indent int) string

type Value 

type Value interface {
	Kinder
	Reprer
}

Value is an elvish value.

func FromJSONInterface 

func FromJSONInterface(v interface{}) Value

FromJSONInterface converts a interface{} that results from json.Unmarshal to a Value.

type ValuesOp 

type ValuesOp struct {
	Func       ValuesOpFunc
	Begin, End int
}

ValuesOp is an operation on an EvalCtx that produce Value's.

func (ValuesOp) Exec 

func (op ValuesOp) Exec(ec *EvalCtx) []Value

Exec executes a ValuesOp and produces Value's.

type ValuesOpFunc 

type ValuesOpFunc func(*EvalCtx) []Value

ValuesOpFunc is the body of ValuesOp.

type Variable 

type Variable interface {
	Set(v Value)
	Get() Value
}

Variable represents an elvish variable.

func MakeRoVariableFromCallback 

func MakeRoVariableFromCallback(get func() Value) Variable

MakeRoVariableFromCallback makes a read-only variable from a get callback.

func MakeVariableFromCallback 

func MakeVariableFromCallback(set func(Value), get func() Value) Variable

MakeVariableFromCallback makes a variable from a set callback and a get callback.

func NewPtrVariable 

func NewPtrVariable(v Value) Variable

func NewPtrVariableWithValidator 

func NewPtrVariableWithValidator(v Value, vld func(Value) error) Variable

func NewRoVariable 

func NewRoVariable(v Value) Variable

Notes

Bugs

  • We rely on the fact that os.Unsetenv always returns nil.

  • When evaluating closures, async access to global variables and ports can be problematic.

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