scala

StringContext

Related Docs: object StringContext | package scala

case class StringContext(parts: String*) extends Product with Serializable

This class provides the basic mechanism to do String Interpolation. String Interpolation allows users to embed variable references directly in *processed* string literals. Here's an example:

val name = "James"
println(s"Hello, $name")  // Hello, James

Any processed string literal is rewritten as an instantiation and method call against this class. For example:

s"Hello, $name"

is rewritten to be:

StringContext("Hello, ", "").s(name)

By default, this class provides the raw, s and f methods as available interpolators.

To provide your own string interpolator, create an implicit class which adds a method to StringContext. Here's an example:

implicit class JsonHelper(private val sc: StringContext) extends AnyVal {
  def json(args: Any*): JSONObject = ...
}
val x: JSONObject = json"{ a: $a }"

Here the JsonHelper extension class implicitly adds the json method to StringContext which can be used for json string literals.

parts

The parts that make up the interpolated string, without the expressions that get inserted by interpolation.

Source
StringContext.scala
Since

2.10.0

Linear Supertypes
Serializable, java.io.Serializable, Product, Equals, AnyRef, Any
Ordering
  1. Alphabetic
  2. By inheritance
Inherited
  1. StringContext
  2. Serializable
  3. Serializable
  4. Product
  5. Equals
  6. AnyRef
  7. Any
Implicitly
  1. by any2stringadd
  2. by StringFormat
  3. by Ensuring
  4. by ArrowAssoc
  1. Hide All
  2. Show all
Learn more about member selection
Visibility
  1. Public
  2. All

Instance Constructors

  1. new StringContext(parts: String*)

    parts

    The parts that make up the interpolated string, without the expressions that get inserted by interpolation.

Value Members

  1. final def !=(arg0: Any): Boolean

    Test two objects for inequality.

    Test two objects for inequality.

    returns

    true if !(this == that), false otherwise.

    Definition Classes
    AnyRef → Any
  2. final def ##(): Int

    Equivalent to x.hashCode except for boxed numeric types and null.

    Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.

    returns

    a hash value consistent with ==

    Definition Classes
    AnyRef → Any
  3. def +(other: String): String

    Implicit information
    This member is added by an implicit conversion from StringContext to any2stringadd[StringContext] performed by method any2stringadd in scala.Predef.
    Definition Classes
    any2stringadd
  4. def ->[B](y: B): (StringContext, B)

    Implicit information
    This member is added by an implicit conversion from StringContext to ArrowAssoc[StringContext] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc
    Annotations
    @inline()
  5. final def ==(arg0: Any): Boolean

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).

    arg0

    the object to compare against this object for equality.

    returns

    true if the receiver object is equivalent to the argument; false otherwise.

    Definition Classes
    AnyRef → Any
  6. final def asInstanceOf[T0]: T0

    Cast the receiver object to be of type T0.

    Cast the receiver object to be of type T0.

    Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.

    returns

    the receiver object.

    Definition Classes
    Any
    Exceptions thrown

    ClassCastException if the receiver object is not an instance of the erasure of type T0.

  7. def checkLengths(args: Seq[Any]): Unit

    Checks that the length of the given argument args is one less than the number of parts supplied to the enclosing StringContext.

    Checks that the length of the given argument args is one less than the number of parts supplied to the enclosing StringContext.

    Exceptions thrown

    IllegalArgumentException if this is not the case.

  8. def clone(): AnyRef

    Create a copy of the receiver object.

    Create a copy of the receiver object.

    The default implementation of the clone method is platform dependent.

    returns

    a copy of the receiver object.

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
    Note

    not specified by SLS as a member of AnyRef

  9. def ensuring(cond: (StringContext) ⇒ Boolean, msg: ⇒ Any): StringContext

    Implicit information
    This member is added by an implicit conversion from StringContext to Ensuring[StringContext] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  10. def ensuring(cond: (StringContext) ⇒ Boolean): StringContext

    Implicit information
    This member is added by an implicit conversion from StringContext to Ensuring[StringContext] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  11. def ensuring(cond: Boolean, msg: ⇒ Any): StringContext

    Implicit information
    This member is added by an implicit conversion from StringContext to Ensuring[StringContext] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  12. def ensuring(cond: Boolean): StringContext

    Implicit information
    This member is added by an implicit conversion from StringContext to Ensuring[StringContext] performed by method Ensuring in scala.Predef.
    Definition Classes
    Ensuring
  13. final def eq(arg0: AnyRef): Boolean

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    Tests whether the argument (arg0) is a reference to the receiver object (this).

    The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:

    • It is consistent: for any non-null instances x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.
    • For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
    • null.eq(null) returns true.

    When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).

    returns

    true if the argument is a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  14. macro def f[A >: Any](args: A*): String

    The formatted string interpolator.

    The formatted string interpolator.

    It inserts its arguments between corresponding parts of the string context. It also treats standard escape sequences as defined in the Scala specification. Finally, if an interpolated expression is followed by a parts string that starts with a formatting specifier, the expression is formatted according to that specifier. All specifiers allowed in Java format strings are handled, and in the same way they are treated in Java.

    For example:

    val height = 1.9d
    val name = "James"
    println(f"$name%s is $height%2.2f meters tall")  // James is 1.90 meters tall
    Exceptions thrown

    IllegalArgumentException if the number of parts in the enclosing StringContext does not exceed the number of arguments arg by exactly 1.

    if a parts string contains a backslash (\) character that does not start a valid escape sequence.

    Note: The f method works by assembling a format string from all the parts strings and using java.lang.String.format to format all arguments with that format string. The format string is obtained by concatenating all parts strings, and performing two transformations:

    1. Let a _formatting position_ be a start of any parts string except the first one. If a formatting position does not refer to a % character (which is assumed to start a format specifier), then the string format specifier %s is inserted.

    2. Any % characters not in formatting positions must begin one of the conversions %% (the literal percent) or %n (the platform-specific line separator).

  15. def finalize(): Unit

    Called by the garbage collector on the receiver object when there are no more references to the object.

    Called by the garbage collector on the receiver object when there are no more references to the object.

    The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.

    Attributes
    protected[java.lang]
    Definition Classes
    AnyRef
    Annotations
    @throws( classOf[java.lang.Throwable] )
    Note

    not specified by SLS as a member of AnyRef

  16. def formatted(fmtstr: String): String

    Returns string formatted according to given format string.

    Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).

    Implicit information
    This member is added by an implicit conversion from StringContext to StringFormat[StringContext] performed by method StringFormat in scala.Predef.
    Definition Classes
    StringFormat
    Annotations
    @inline()
  17. final def getClass(): Class[_]

    A representation that corresponds to the dynamic class of the receiver object.

    A representation that corresponds to the dynamic class of the receiver object.

    The nature of the representation is platform dependent.

    returns

    a representation that corresponds to the dynamic class of the receiver object.

    Definition Classes
    AnyRef → Any
    Note

    not specified by SLS as a member of AnyRef

  18. final def isInstanceOf[T0]: Boolean

    Test whether the dynamic type of the receiver object is T0.

    Test whether the dynamic type of the receiver object is T0.

    Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.

    returns

    true if the receiver object is an instance of erasure of type T0; false otherwise.

    Definition Classes
    Any
  19. final def ne(arg0: AnyRef): Boolean

    Equivalent to !(this eq that).

    Equivalent to !(this eq that).

    returns

    true if the argument is not a reference to the receiver object; false otherwise.

    Definition Classes
    AnyRef
  20. final def notify(): Unit

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Wakes up a single thread that is waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  21. final def notifyAll(): Unit

    Wakes up all threads that are waiting on the receiver object's monitor.

    Wakes up all threads that are waiting on the receiver object's monitor.

    Definition Classes
    AnyRef
    Note

    not specified by SLS as a member of AnyRef

  22. val parts: String*

    The parts that make up the interpolated string, without the expressions that get inserted by interpolation.

  23. def raw(args: Any*): String

    The raw string interpolator.

    The raw string interpolator.

    It inserts its arguments between corresponding parts of the string context. As opposed to the simple string interpolator s, this one does not treat standard escape sequences as defined in the Scala specification.

    For example, the raw processed string raw"a\nb" is equal to the scala string "a\\nb".

    Note: Even when using the raw interpolator, Scala will preprocess unicode escapes. For example:

    scala> raw"\u0023"
    res0: String = #
    Exceptions thrown

    IllegalArgumentException if the number of parts in the enclosing StringContext does not exceed the number of arguments arg by exactly 1.

  24. def s(args: Any*): String

    The simple string interpolator.

    The simple string interpolator.

    It inserts its arguments between corresponding parts of the string context. It also treats standard escape sequences as defined in the Scala specification. Here's an example of usage:

    val name = "James"
    println(s"Hello, $name")  // Hello, James

    In this example, the expression $name is replaced with the toString of the variable name. The s interpolator can take the toString of any arbitrary expression within a ${} block, for example:

    println(s"1 + 1 = ${1 + 1}")

    will print the string 1 + 1 = 2.

    Exceptions thrown

    IllegalArgumentException if the number of parts in the enclosing StringContext does not exceed the number of arguments arg by exactly 1.

    StringContext.InvalidEscapeException if a parts string contains a backslash (\) character that does not start a valid escape sequence.

  25. def standardInterpolator(process: (String) ⇒ String, args: Seq[Any]): String

  26. final def synchronized[T0](arg0: ⇒ T0): T0

    Definition Classes
    AnyRef
  27. final def wait(): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  28. final def wait(arg0: Long, arg1: Int): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  29. final def wait(arg0: Long): Unit

    Definition Classes
    AnyRef
    Annotations
    @throws( ... )
  30. def [B](y: B): (StringContext, B)

    Implicit information
    This member is added by an implicit conversion from StringContext to ArrowAssoc[StringContext] performed by method ArrowAssoc in scala.Predef.
    Definition Classes
    ArrowAssoc

Inherited from Serializable

Inherited from java.io.Serializable

Inherited from Product

Inherited from Equals

Inherited from AnyRef

Inherited from Any

Inherited by implicit conversion any2stringadd from StringContext to any2stringadd[StringContext]

Inherited by implicit conversion StringFormat from StringContext to StringFormat[StringContext]

Inherited by implicit conversion Ensuring from StringContext to Ensuring[StringContext]

Inherited by implicit conversion ArrowAssoc from StringContext to ArrowAssoc[StringContext]

Ungrouped