Class Scalar
- java.lang.Object
-
- sleep.runtime.Scalar
-
- All Implemented Interfaces:
java.io.Serializable
public class Scalar extends java.lang.Object implements java.io.Serializable
A scalar is the universal data type for sleep variables. Scalars can have numerical values of integer, double, or long. Scalars can have a string value. Scalars can also contain a reference to a scalar array, scalar hash, or a generic Java object.
Numerical and String values are stored as ScalarTypes. Arrays and Hashes are stored in ScalarArray and ScalarHash containers respectively.
Instantiating a Scalar
Instantiating a Scalar is most easily done using the sleep.runtime.SleepUtils class. The SleepUtils class contains several static methods for creating a Scalar object from data.
The general pattern for this is a
SleepUtils.getScalar(data)
methods. There are static getScalar() methods that take a double, int, long, Object, or a String as a parameter.There are even methods for wrapping java data structures into a scalar array or scalar hash. Methods also exist to copy data from one scalar into another new scalar.
Examples:
Scalar anInt = SleepUtils.getScalar(3); // create an int scalar Scalar aDouble = SleepUtils.getScalar(4.5); // create a double scalar Scalar aString = SleepUtils.getScalar("hello"); // string scalar Scalar anArray = SleepUtils.getArrayWrapper(new LinkedList(); // array scalar
Working with Scalar Arrays
To add a value to a Scalar array:
Scalar arrayScalar = SleepUtils.getArray(); // empty array arrayScalar.getArray().add(SleepUtils.getScalar("value"), 0);
To iterate through all of the values in a Scalar array:
Iterator i = arrayScalar.getArray().scalarIterator(); while (i.hasNext()) { Scalar temp = (Scalar)i.next(); }
Working with Scalar Hashes
To add a value to a Scalar hashtable:
Scalar hashScalar = SleepUtils.getHashScalar(); // blank hashtable Scalar temp = hashScalar.getHash().getAt(SleepUtils.getScalar("key")); temp.setValue(SleepUtils.getScalar("value"));
The second line obtains a Scalar for "key". The returned Scalar is just a container. It is possible to set the value of the returned scalar using the setValue method.
Internally scalar values in sleep are passed by value. Methods like setValue inside of the Scalar class take care of copying the value. Externally though Scalar objects are passed by reference. When you call getAt() in the ScalarHash you are obtaining a reference to a Scalar inside of the hashtable. When you change the value of the Scalar you obtained, you change the value of the Scalar in the hashtable.
- See Also:
SleepUtils
,ScalarType
,ScalarArray
,ScalarHash
, Serialized Form
-
-
Field Summary
Fields Modifier and Type Field Description protected ScalarArray
array
protected ScalarHash
hash
protected ScalarType
value
-
Constructor Summary
Constructors Constructor Description Scalar()
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description double
doubleValue()
the double value of this scalarScalarType
getActualValue()
Returns the actual non-array/non-hash value this scalar contains.ScalarArray
getArray()
returns a scalar array referenced by this scalar iff this scalar contains an array referenceScalarHash
getHash()
returns a scalar hash referenced by this scalar iff this scalar contains a hash referenceScalarType
getValue()
Returns the container for the scalars value.java.lang.Object
identity()
returns an identity value for this scalar.int
intValue()
the int value of this scalarlong
longValue()
the long value of this scalarjava.lang.Object
objectValue()
the object value of this scalarboolean
sameAs(Scalar other)
compares two scalars in terms of their identity.void
setValue(Scalar newValue)
clones the value from the specified scalar and gives this scalar a copy of the valuevoid
setValue(ScalarArray _array)
set the value of this scalar container to a scalar arrayvoid
setValue(ScalarHash _hash)
set the value of this scalar container to a scalar hashvoid
setValue(ScalarType _value)
set the value of this scalar container to a scalar value of some typejava.lang.String
stringValue()
the string value of this scalarjava.lang.String
toString()
-
-
-
Field Detail
-
value
protected ScalarType value
-
array
protected ScalarArray array
-
hash
protected ScalarHash hash
-
-
Method Detail
-
getActualValue
public ScalarType getActualValue()
Returns the actual non-array/non-hash value this scalar contains. This is mainly for use by internal sleep classes that do not want to accidentally convert a hash/array to a string.
-
getValue
public ScalarType getValue()
Returns the container for the scalars value. If this is an array or hash scalar then they will be converted to a string scalar and returned. If this scalar is completely null then null will be returned which will mess up the interpreter somewhere
-
stringValue
public java.lang.String stringValue()
the string value of this scalar
-
intValue
public int intValue()
the int value of this scalar
-
doubleValue
public double doubleValue()
the double value of this scalar
-
longValue
public long longValue()
the long value of this scalar
-
objectValue
public java.lang.Object objectValue()
the object value of this scalar
-
getArray
public ScalarArray getArray()
returns a scalar array referenced by this scalar iff this scalar contains an array reference
-
getHash
public ScalarHash getHash()
returns a scalar hash referenced by this scalar iff this scalar contains a hash reference
-
setValue
public void setValue(ScalarType _value)
set the value of this scalar container to a scalar value of some type
-
setValue
public void setValue(ScalarArray _array)
set the value of this scalar container to a scalar array
-
setValue
public void setValue(ScalarHash _hash)
set the value of this scalar container to a scalar hash
-
identity
public java.lang.Object identity()
returns an identity value for this scalar. the identity value is used in set operations. basically any scalar values that are handled by reference (object,s arrays, and hashes) use their reference as their identity. other values used their string value as their identity (doubles that do not have a decimal point will be converted to longs).
-
sameAs
public boolean sameAs(Scalar other)
compares two scalars in terms of their identity. scalars that hold references (array, object, and hash) are compared by reference where other values are compared by their string value. doubles with a round value will be converted to a long
-
toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
-
setValue
public void setValue(Scalar newValue)
clones the value from the specified scalar and gives this scalar a copy of the value
-
-