Scala Compiler2.12.18 < Back
 

# Packages

-  package root

  The Scala compiler and reflection APIs.

  The Scala compiler and reflection APIs.

  Definition Classes
    root
-  package scala
  Definition Classes
    root
-  package tools
  Definition Classes
    scala
-  package nsc
  Definition Classes
    tools
-  package interpreter

  The main REPL related classes and values are as follows.

  The main REPL related classes and values are as follows. In addition to standard compiler classes Global and Settings, there are:

  History: an interface for session history. Completion: an interface for tab completion. ILoop (formerly InterpreterLoop): The umbrella class for a session. IMain (formerly Interpreter): Handles the evolving state of the session and handles submitting code to the compiler and handling the output. InteractiveReader: how ILoop obtains input. History: an interface for session history. Completion: an interface for tab completion. Power: a repository for more advanced/experimental features.

  ILoop contains { in: InteractiveReader, intp: IMain, settings: Settings, power: Power } InteractiveReader contains { history: History, completion: Completion } IMain contains { global: Global }

  Definition Classes
    nsc
-  package session

  Files having to do with the state of a repl session: lines of text entered, types and terms defined, etc.

  Files having to do with the state of a repl session: lines of text entered, types and terms defined, etc.

  Definition Classes
    interpreter
- AbstractFileClassLoader
- AbstractOrMissingHandler
- CommandLine
- Completion
- Delimited
- EchoReader
- ExprTyper
- ILoop
- IMain
- IMainOps
- ISettings
- Imports
- InteractiveReader
- Javap
- Javap8
- Javap9
- JavapClass
- JavapProvider
- JavapTask
- JavapTool
- Logger
- LoopCommands
- MemberHandlers
- NamedParam
- NamedParamClass
- NamedParamCreator
- Naming
- NoCompletion
- Parsed
- Pasted
- Phased
- Power
- PresentationCompilation
- PresentationCompilerCompleter
- ProcessResult
- ReplConfig
- ReplDir
- ReplGlobal
- ReplOutput
- ReplProps
- ReplReporter
- ReplStrings
- ReplVals
- Results
- RichClass
- Scripted
- SimpleReader
- SplashLoop
- SplashReader
- StdReplTags
- StdReplVals
- Tabulator
- TapMaker
- VariColumnTabulator
- WriterOutputStream
- {{

c

scala.tools.nsc.interpreter

# IMain 

###
Companion object IMain

#### class IMain extends Imports with PresentationCompilation with Closeable

An interpreter for Scala code.

The main public entry points are compile(), interpret(), and bind(). The compile() method loads a complete Scala file. The interpret() method executes one line of Scala code at the request of the user. The bind() method binds an object to a variable that can then be used by later interpreted code.

The overall approach is based on compiling the requested code and then using a Java classloader and Java reflection to run the code and access its results.

In more detail, a single compiler instance is used to accumulate all successfully compiled or interpreted Scala code. To "interpret" a line of code, the compiler generates a fresh object that includes the line of code and which has public member(s) to export all variables defined by that code. To extract the result of an interpreted line to show the user, a second "result object" is created which imports the variables exported by the above object and then exports members called "$eval" and "$print". To accommodate user expressions that read from variables or methods defined in previous statements, "import" statements are used.

This interpreter shares the strengths and weaknesses of using the full compiler-to-Java. The main strength is that interpreted code behaves exactly as does compiled code, including running at full speed. The main weakness is that redefining classes and methods is not handled properly, because rebinding at the Java level is technically difficult.

Self Type
  IMain
Source
  IMain.scala

Linear Supertypes
Closeable, AutoCloseable, PresentationCompilation, Imports, AnyRef, Any
Known Subclasses
ILoopInterpreter, Interpreter
 
Ordering

1. Alphabetic
2. By Inheritance

Inherited

1. IMain
2. Closeable
3. AutoCloseable
4. PresentationCompilation
5. Imports
6. AnyRef
7. Any

Implicitly

1. by IMainOps
2. by any2stringadd
3. by StringFormat
4. by Ensuring
5. by ArrowAssoc

1. Hide All
2. Show All

Visibility

1. Public
2. All

### Instance Constructors

1.  new IMain(initialSettings: Settings)
2.  new IMain(initialSettings: Settings, out: JPrintWriter)

### Type Members

1.  abstract class PhaseDependentOps extends AnyRef
2.  class ReadEvalPrint extends AnyRef

   Here is where we:

   Here is where we:

   1) Read some source code, and put it in the "read" object. 2) Evaluate the read object, and put the result in the "eval" object. 3) Create a String for human consumption, and put it in the "print" object.

   Read! Eval! Print! Some of that not yet centralized here.

3.  implicit class ReplTypeOps extends AnyRef
4.  class Request extends AnyRef

   One line of code submitted by the user for interpretation

5.  case class ComputedImports(header: String, prepend: String, append: String, access: String) extends Product with Serializable

   Compute imports that allow definitions from previous requests to be visible in a new request.

   Compute imports that allow definitions from previous requests to be visible in a new request. Returns three or four pieces of related code:

   0. Header code fragment that should go at the beginning of the compilation unit, specifically, import Predef.

   1. An initial code fragment that should go before the code of the new request.

   2. A code fragment that should go after the code of the new request.

   3. An access path which can be traversed to access any bindings inside code wrapped by #1 and #2 .

   The argument is a set of Names that need to be imported.

   Limitations: This method is not as precise as it could be. (1) It does not process wildcard imports to see what exactly they import. (2) If it imports any names from a request, it imports all of them, which is not really necessary. (3) It imports multiple same-named implicits, but only the last one imported is actually usable.

   Definition Classes
     Imports
6.  abstract class PresentationCompileResult extends AnyRef
   Definition Classes
     PresentationCompilation

### Value Members

1.  final def !=(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
2.  final def ##(): Int
   Definition Classes
     AnyRef → Any
3.  def +(other: String): String
   Implicit
     This member is added by an implicit conversion from IMain to any2stringadd[IMain] performed by method any2stringadd in scala.Predef.
   Definition Classes
     any2stringadd
4.  def ->[B](y: B): (IMain, B)
   Implicit
     This member is added by an implicit conversion from IMain to ArrowAssoc[IMain] performed by method ArrowAssoc in scala.Predef.
   Definition Classes
     ArrowAssoc
   Annotations
     @inline()
5.  final def ==(arg0: Any): Boolean
   Definition Classes
     AnyRef → Any
6.  def addUrlsToClassPath(urls: URL*): Unit

   Adds all specified jars to the compile and runtime classpaths.

   Adds all specified jars to the compile and runtime classpaths.

   urls

     The list of items to add to the compile and runtime classpaths.

   Note

     Currently only supports jars, not directories.

7.  def allDefinedNames: List[Global.Name]
8.  def allHandlers: collection.immutable.List[(memberHandlers)#MemberHandler]
9.  final def asInstanceOf[T0]: T0
   Definition Classes
     Any
10.  def backticked(s: String): String
11.  def beQuietDuring[T](body: ⇒ T): T

    Temporarily be quiet

12.  def beSilentDuring[T](operation: ⇒ T): T
13.  def bind[T](name: String, value: T)(implicit arg0: reflect.api.JavaUniverse.TypeTag[T], arg1: ClassTag[T]): Result
14.  def bind(p: NamedParam): Result
15.  def bind(name: String, boundType: String, value: Any, modifiers: List[String] = Nil): Result

    Bind a specified name to a specified value.

    Bind a specified name to a specified value. The name may later be used by expressions passed to interpret.

    A fresh `ReadEvalPrint`, which defines a `line` package, is used to compile a custom `eval` object that wraps the bound value.

    If the bound value is successfully installed, then bind the name by interpreting `val name = $line42.$eval.value`.

    name

      the variable name to bind

    boundType

      the type of the variable, as a string

    value

      the object value to bind to it

    returns

      an indication of whether the binding succeeded

16.  def classLoader: util.AbstractFileClassLoader
17.  def classOfTerm(id: String): Option[JClass]
18.  def cleanMemberDecl(owner: Global.Symbol, member: Global.Name): Global.Type
19.  def cleanTypeAfterTyper(sym: ⇒ Global.Symbol): Global.Type
20.  def clearExecutionWrapper(): Unit
21.  def clone(): AnyRef
    Attributes
      protected[lang]
    Definition Classes
      AnyRef
    Annotations
      @throws( ... ) @native()
22.  def close(): Unit

    This instance is no longer needed, so release any resources it is using.

    This instance is no longer needed, so release any resources it is using. The reporter's output gets flushed.

    Definition Classes
      IMain → Closeable → AutoCloseable
23.  def compileSources(sources: SourceFile*): Boolean

    Compile an nsc SourceFile.

    Compile an nsc SourceFile. Returns true if there are no compilation errors, or false otherwise.

24.  def compileSourcesKeepingRun(sources: SourceFile*): (Boolean, Run)
25.  def compileString(code: String): Boolean

    Compile a string.

    Compile a string. Returns true if there are no compilation errors, or false otherwise.

26.  def compilerClasspath: Seq[URL]
27.  def dealiasNonPublic(tp: Global.Type): Global.Type
28.  def debugging[T](msg: String)(res: T): T
29.  def definedSymbolList: collection.immutable.List[Global.Symbol]
30.  def definedTerms: collection.immutable.List[Global.TermName]
31.  def definedTypes: List[Global.TypeName]
32.  def directBind[T](name: String, value: T)(implicit arg0: reflect.api.JavaUniverse.TypeTag[T], arg1: ClassTag[T]): Result
33.  def directBind(p: NamedParam): Result
34.  def directBind(name: String, boundType: String, value: Any): Result
35.  def echoKind: ((tpe: _1.intp.global.Type, kind: _1.intp.global.Kind, verbose: Boolean)Unit) forSome {val _1: IMainOps}
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
36.  def echoTypeSignature: ((sym: _1.intp.global.Symbol, verbose: Boolean)Unit) forSome {val _1: IMainOps}
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
37.  def echoTypeStructure: ((sym: _1.intp.global.Symbol)Unit) forSome {val _1: IMainOps}
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
38.  final def ensureClassLoader(): Unit
39.  def ensuring(cond: (IMain) ⇒ Boolean, msg: ⇒ Any): IMain
    Implicit
      This member is added by an implicit conversion from IMain to Ensuring[IMain] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
40.  def ensuring(cond: (IMain) ⇒ Boolean): IMain
    Implicit
      This member is added by an implicit conversion from IMain to Ensuring[IMain] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
41.  def ensuring(cond: Boolean, msg: ⇒ Any): IMain
    Implicit
      This member is added by an implicit conversion from IMain to Ensuring[IMain] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
42.  def ensuring(cond: Boolean): IMain
    Implicit
      This member is added by an implicit conversion from IMain to Ensuring[IMain] performed by method Ensuring in scala.Predef.
    Definition Classes
      Ensuring
43.  final def eq(arg0: AnyRef): Boolean
    Definition Classes
      AnyRef
44.  def equals(arg0: Any): Boolean
    Definition Classes
      AnyRef → Any
45.  def executionWrapper: String
46.  def finalize(): Unit
    Definition Classes
      IMain → AnyRef
47.  def flatPath(sym: Global.Symbol): String
48.  final def getClass(): Class[_]
    Definition Classes
      AnyRef → Any
    Annotations
      @native()
49.  def getClassIfDefined(path: String): Global.Symbol
50.  def getModuleIfDefined(path: String): Global.Symbol
51.  lazy val global: Global
52.  def hashCode(): Int
    Definition Classes
      AnyRef → Any
    Annotations
      @native()
53.  def implicitSymbolsBySource: List[(Global.Symbol, List[Global.Symbol])]
    Definition Classes
      Imports
54.  def implicitsCommand(line: String): String
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
55.  def importHandlers: collection.immutable.List[(memberHandlers)#ImportHandler]
56.  def importsCode(wanted: Set[Global.Name], wrapper: Wrapper, generousImports: Boolean): ComputedImports
    Attributes
      protected
    Definition Classes
      Imports
57.  def initialize(postInitSignal: ⇒ Unit): Unit
58.  def initializeSynchronous(): Unit
59.  def interpret(line: String, synthetic: Boolean): Result
60.  def interpret(line: String): Result

    Interpret one line of input.

    Interpret one line of input. All feedback, including parse errors and evaluation results, are printed via the supplied compiler's reporter. Values defined are available for future interpreted strings.

    The return value is whether the line was interpreter successfully, e.g. that there were no parse errors.

61.  def interpretSynthetic(line: String): Result
62.  val intp: IMain
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
63.  lazy val isClassBased: Boolean
64.  def isInitializeComplete: Boolean
65.  final def isInstanceOf[T0]: Boolean
    Definition Classes
      Any
66.  lazy val isettings: ISettings

    interpreter settings

67.  def kindCommandInternal(typeString: String, verbose: Boolean): Unit
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
68.  def languageWildcardHandlers: collection.immutable.List[(memberHandlers)#ImportHandler]
    Definition Classes
      Imports
69.  def lastRequest: Request
70.  def lastWarnings: List[(Global.Position, String)]
71.  lazy val memberHandlers: MemberHandlers { val intp: IMain.this.type }
72.  def mostRecentVar: String

    Returns the name of the most recent interpreter result.

    Returns the name of the most recent interpreter result. Mostly this exists so you can conveniently invoke methods on the previous result.

73.  def namedDefinedTerms: collection.immutable.List[Global.TermName]
74.  final def ne(arg0: AnyRef): Boolean
    Definition Classes
      AnyRef
75.  def newCompiler(settings: Settings, reporter: Reporter): ReplGlobal

    Instantiate a compiler.

    Instantiate a compiler. Overridable.

    Attributes
      protected
76.  def newPresentationCompiler(): interactive.Global

    Create an instance of the presentation compiler with a classpath comprising the REPL's configured classpath and the classes output by previously compiled REPL lines.

    Create an instance of the presentation compiler with a classpath comprising the REPL's configured classpath and the classes output by previously compiled REPL lines.

    You may directly interact with this compiler from any thread, although you must not access it concurrently from multiple threads.

    You may downcast the `reporter` to `StoreReporter` to access type errors.

    Definition Classes
      PresentationCompilation
77.  final def notify(): Unit
    Definition Classes
      AnyRef
    Annotations
      @native()
78.  final def notifyAll(): Unit
    Definition Classes
      AnyRef
    Annotations
      @native()
79.  def onlyTerms(xs: List[Global.Name]): List[Global.TermName]
    Attributes
      protected
80.  def onlyTypes(xs: List[Global.Name]): List[Global.TypeName]
    Attributes
      protected
81.  def originalPath(sym: Global.Symbol): String
82.  def originalPath(name: Global.Name): String
83.  def originalPath(name: String): String
84.  val out: JPrintWriter
    Attributes
      protected
85.  def parentClassLoader: ClassLoader

    Parent classloader.

    Parent classloader. Overridable.

    Attributes
      protected
86.  var partialInput: String
87.  def prevRequestList: collection.immutable.List[Request]
88.  def printAfterTyper(msg: ⇒ String): Unit
    Implicit
      This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
    Definition Classes
      IMainOps
89.  def quietBind(p: NamedParam): Result
90.  def quietRun[T](code: String): Result
91.  val readInstanceName: String
92.  def readRootPath(readPath: String): Global.Symbol
93.  def rebind(p: NamedParam): Result
94.  def recordRequest(req: Request): Unit
95.  def replScope: Global.Scope
96.  lazy val reporter: ReplReporter
97.  def reset(): Unit

    Reset this interpreter, forgetting all user-specified requests.

98.  def resetClassLoader(): Unit
99.  def runtimeClassAndTypeOfTerm(id: String): Option[(JClass, Global.Type)]
100.  def runtimeMirror: Mirror
101.  def runtimeTypeOfTerm(id: String): Global.Type
102.  def setExecutionWrapper(code: String): Unit
103.  def settings: Settings
104.  def showCodeIfDebugging(code: String): Unit
105.  def showDirectory(): Unit
106.  def symbolDefString(sym: Global.Symbol): String
107.  def symbolOfIdent(id: String): Global.Symbol
108.  def symbolOfLine(code: String): Global.Symbol
109.  def symbolOfName(id: Global.Name): Global.Symbol
110.  def symbolOfTerm(id: String): Global.Symbol
111.  def symbolOfType(id: String): Global.Symbol
112.  final def synchronized[T0](arg0: ⇒ T0): T0
     Definition Classes
       AnyRef
113.  def toString(): String
     Definition Classes
       AnyRef → Any
114.  def translateEnclosingClass(n: String): Option[String]
115.  def translateOriginalPath(p: String): String
116.  def translatePath(path: String): Option[String]
117.  def translateSimpleResource(path: String): Option[String]

     If path represents a class resource in the default package, see if the corresponding symbol has a class file that is a REPL artifact residing at a different resource path.

     If path represents a class resource in the default package, see if the corresponding symbol has a class file that is a REPL artifact residing at a different resource path. Translate X.class to $line3/$read$iw$X.class.

118.  def tryTwice(op: ⇒ Global.Symbol): Global.Symbol

     It's a bit of a shotgun approach, but for now we will gain in robustness.

     It's a bit of a shotgun approach, but for now we will gain in robustness. Try a symbol-producing operation at phase typer, and if that is NoSymbol, try again at phase flatten. I'll be able to lose this and run only from exitingTyper as soon as I figure out exactly where a flat name is sneaking in when calculating imports.

119.  def typeCommandInternal(expr: String, verbose: Boolean): Unit

     TODO - -n normalize -l label with case class parameter names -c complete - leave nothing out

     TODO - -n normalize -l label with case class parameter names -c complete - leave nothing out

     Implicit
       This member is added by an implicit conversion from IMain to IMainOps performed by method IMainOps in scala.tools.nsc.interpreter.
     Definition Classes
       IMainOps
120.  def typeOfExpression(expr: String, silent: Boolean = true): Global.Type
121.  def typeOfTerm(id: String): Global.Type
122.  def unqualifiedIds: List[String]
123.  def valueOfTerm(id: String): Option[Any]
124.  final def wait(): Unit
     Definition Classes
       AnyRef
     Annotations
       @throws( ... )
125.  final def wait(arg0: Long, arg1: Int): Unit
     Definition Classes
       AnyRef
     Annotations
       @throws( ... )
126.  final def wait(arg0: Long): Unit
     Definition Classes
       AnyRef
     Annotations
       @throws( ... ) @native()
127.  def withLabel[A](temp: String)(body: ⇒ A): A
128.  def withoutTruncating[A](body: ⇒ A): A
129.  def withoutUnwrapping(op: ⇒ Unit): Unit
130.  def withoutWarnings[T](body: ⇒ T): T
131.  def →[B](y: B): (IMain, B)
     Implicit
       This member is added by an implicit conversion from IMain to ArrowAssoc[IMain] performed by method ArrowAssoc in scala.Predef.
     Definition Classes
       ArrowAssoc
132.  object deconstruct extends StructuredTypeStrings
133.  object exprTyper extends ExprTyper
134.  object flatOp extends PhaseDependentOps
135.  object naming extends Naming
136.  object parse

     Parse a line into and return parsing result (error, incomplete or success with list of trees)

137.  object replOutput extends ReplOutput
138.  object typerOp extends PhaseDependentOps
139.  object PresentationCompileResult
     Definition Classes
       PresentationCompilation

### Deprecated Value Members

1.  def formatted(fmtstr: String): String
   Implicit
     This member is added by an implicit conversion from IMain to StringFormat[IMain] performed by method StringFormat in scala.Predef.
   Definition Classes
     StringFormat
   Annotations
     @deprecated @inline()
   Deprecated

     (Since version 2.12.16) Use `formatString.format(value)` instead of `value.formatted(formatString)`, or use the `f""` string interpolator. In Java 15 and later, `formatted` resolves to the new method in String which has reversed parameters.

2.  def setContextClassLoader(): Unit
   Annotations
     @deprecated
   Deprecated

     (Since version 2.12.0) The thread context classloader is now set and restored around execution of REPL line, this method is now a no-op.

3.  def virtualDirectory: ReplDir
   Annotations
     @deprecated
   Deprecated

     (Since version 2.11.0) Use replOutput.dir instead

### Inherited from Closeable

### Inherited from AutoCloseable

### Inherited from PresentationCompilation

### Inherited from Imports

### Inherited from AnyRef

### Inherited from Any

### Inherited by implicit conversion IMainOps from IMain to IMainOps

### Inherited by implicit conversion any2stringadd from IMain to any2stringadd[IMain]

### Inherited by implicit conversion StringFormat from IMain to StringFormat[IMain]

### Inherited by implicit conversion Ensuring from IMain to Ensuring[IMain]

### Inherited by implicit conversion ArrowAssoc from IMain to ArrowAssoc[IMain]

### Ungrouped