TypeConstraint (Unofficial IntelliJ Community Edition API docs)

All Known Subinterfaces:

TypeConstraint.Exact

All Known Implementing Classes:

TypeConstraint.Constrained
```
public interface TypeConstraint
```
Immutable object representing a number of type constraints applied to some reference value. Type constraints represent a lattice with TypeConstraints.TOP and TypeConstraints.BOTTOM elements, as well as join(TypeConstraint) and meet(TypeConstraint) operations. Besides TOP and BOTTOM there are two types of constrains: TypeConstraint.Exact (value is known to have exactly some JVM type) and TypeConstraint.Constrained (value is instanceof zero or more JVM types and not instanceof zero or more JVM types). value is instance of some type and value is not an instance of some type. Null or primitive types are not handled here.

Nested Class Summary

Nested Classes
Modifier and Type	Interface and Description
`static class`	`TypeConstraint.Constrained` A non-exact, constrained type
`static interface`	`TypeConstraint.Exact` Represents an exact type.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default DfType`	`asDfType()`
`static TypeConstraint`	`fromDfType(DfType type)`
`default java.lang.String`	`getAssignabilityExplanation(TypeConstraint otherType, boolean expectedAssignable)`
`default java.lang.String`	`getPresentationText(PsiType type)`
`default PsiType`	`getPsiType(Project project)`
`default <any>`	`instanceOfTypes()`
`default boolean`	`isComparedByEquals()`
`default boolean`	`isExact()`
`boolean`	`isSuperConstraintOf(TypeConstraint other)`
`TypeConstraint`	`join(TypeConstraint other)`
`TypeConstraint`	`meet(TypeConstraint other)`
`default <any>`	`notInstanceOfTypes()`
`default java.lang.String`	`toShortString()`
`default TypeConstraint`	`tryNegate()`

- Method Detail
  - join
```
TypeConstraint join(TypeConstraint other)
```
    Parameters:
    
    other - other constraint to join with
    
    Returns:
    
    joined constraint. If some type satisfies either this or other constraint, it also satisfies the resulting constraint.
  - meet
```
TypeConstraint meet(TypeConstraint other)
```
    Parameters:
    
    other - other constraint to meet with
    
    Returns:
    
    intersection constraint. If some type satisfies the resulting constraint, it also satisfies both this and other constraints.
  - isSuperConstraintOf
```
boolean isSuperConstraintOf(TypeConstraint other)
```
    Parameters:
    
    other - other constraint to check
    
    Returns:
    
    true if every type satisfied by other constraint is also satisfied by this constraint.
  - tryNegate
```
default TypeConstraint tryNegate()
```
    Returns:
    
    negated constraint (a constraint that satisfied only by types not satisfied by this constraint). Null if such a constraint cannot be created.
  - getPsiType
```
default PsiType getPsiType(Project project)
```
    Parameters:
    
    project - current project
    
    Returns:
    
    the narrowest PsiType that contains all the values satisfied by this constraint.
  - getPresentationText
```
default java.lang.String getPresentationText(PsiType type)
```
    Parameters:
    
    type - declared PsiType of the value
    
    Returns:
    
    presentation text that tells about additional constraints; can be empty if no additional constraints are known
  - isExact
```
default boolean isExact()
```
    Returns:
    
    true if this constraint represents an exact type
  - isComparedByEquals
```
default boolean isComparedByEquals()
```
    Returns:
    
    true if the types represented by this constraint are known to be compared by .equals() within DFA algorithm
  - getAssignabilityExplanation
```
default java.lang.String getAssignabilityExplanation(TypeConstraint otherType,
                                                     boolean expectedAssignable)
```
    Parameters:
    
    otherType - other type
    
    expectedAssignable - whether other type is expected to be assignable from this, or not
    
    Returns:
    
    textual explanation about why expected assignability cannot be satisfied; null if it can be satisfied, or explanation cannot be found.
  - instanceOfTypes
```
default <any> instanceOfTypes()
```
    Returns:
    
    stream of "instanceof" constraints of this type
  - notInstanceOfTypes
```
default <any> notInstanceOfTypes()
```
    Returns:
    
    stream of "not-instanceof" constraints of this type
  - asDfType
```
default DfType asDfType()
```
    Returns:
    
    a DfType that represents any object that satisfies this constraint, or null (nullability is unknown)
  - toShortString
```
default java.lang.String toShortString()
```
    Returns:
    
    a short string representation
  - fromDfType
```
static TypeConstraint fromDfType(DfType type)
```
    Parameters:
    
    type - DfType to extract TypeConstraint from
    
    Returns:
    
    an extracted type constraint

Interface TypeConstraint

Nested Class Summary

Method Summary

Method Detail

join

meet

isSuperConstraintOf

tryNegate

getPsiType

getPresentationText

isExact

isComparedByEquals

getAssignabilityExplanation

instanceOfTypes

notInstanceOfTypes

asDfType

toShortString

fromDfType