Expr (Apache Jena ARQ)

All Known Implementing Classes:

E_Add, E_BNode, E_Bound, E_Call, E_Cast, E_Coalesce, E_Conditional, E_Datatype, E_DateTimeDay, E_DateTimeHours, E_DateTimeMinutes, E_DateTimeMonth, E_DateTimeSeconds, E_DateTimeTimezone, E_DateTimeTZ, E_DateTimeYear, E_Divide, E_Equals, E_Exists, E_Function, E_FunctionDynamic, E_GreaterThan, E_GreaterThanOrEqual, E_IRI, E_IsBlank, E_IsIRI, E_IsLiteral, E_IsNumeric, E_IsURI, E_Lang, E_LangMatches, E_LessThan, E_LessThanOrEqual, E_LogicalAnd, E_LogicalNot, E_LogicalOr, E_MD5, E_Multiply, E_NotEquals, E_NotExists, E_NotOneOf, E_Now, E_NumAbs, E_NumCeiling, E_NumFloor, E_NumRound, E_OneOf, E_OneOfBase, E_Random, E_Regex, E_SameTerm, E_SHA1, E_SHA224, E_SHA256, E_SHA384, E_SHA512, E_Str, E_StrAfter, E_StrBefore, E_StrConcat, E_StrContains, E_StrDatatype, E_StrEncodeForURI, E_StrEndsWith, E_StrLang, E_StrLength, E_StrLowerCase, E_StrReplace, E_StrStartsWith, E_StrSubstring, E_StrUpperCase, E_StrUUID, E_Subtract, E_UnaryMinus, E_UnaryPlus, E_URI, E_UUID, E_Version, ExprAggregator, ExprDigest, ExprFunction, ExprFunction0, ExprFunction1, ExprFunction2, ExprFunction3, ExprFunctionN, ExprFunctionOp, ExprNode, ExprSystem, ExprVar, NodeValue, NodeValueBoolean, NodeValueDecimal, NodeValueDouble, NodeValueDT, NodeValueDuration, NodeValueFloat, NodeValueInteger, NodeValueNode, NodeValueString
```
public interface Expr
```

Field Summary

Fields
Modifier and Type Field and Description

static int CMP_EQUAL

static int CMP_GREATER

static int CMP_INDETERMINATE

static int CMP_LESS

static int CMP_UNEQUAL

Fields
Modifier and Type	Field and Description
`static int`	`CMP_EQUAL`
`static int`	`CMP_GREATER`
`static int`	`CMP_INDETERMINATE`
`static int`	`CMP_LESS`
`static int`	`CMP_UNEQUAL`

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`Expr`	`applyNodeTransform(NodeTransform transform)` Rewrite, applying a node->node transformation
`Var`	`asVar()` Convert to a Var variable.
`Expr`	`copySubstitute(Binding binding)` Deep copy with substitution
`Expr`	`deepCopy()` Deep copy
`boolean`	`equals(Expr other, boolean bySyntax)` General equality operation - consider this to be 'protected'
`boolean`	`equals(Object other)`
`boolean`	`equalsBySyntax(Expr other)`
`NodeValue`	`eval(Binding binding, FunctionEnv env)` Evaluate this expression against the binding
`NodeValue`	`getConstant()` NodeValue constant (returns null if not a constant)
`ExprVar`	`getExprVar()` Variable (or null)
`ExprFunction`	`getFunction()` Get the function (returns null if not a function)
`String`	`getVarName()` Variable name (returns null if not a variable)
`Set<Var>`	`getVarsMentioned()` Variables used by this expression - excludes variables scoped to (NOT)EXISTS
`int`	`hashCode()` `Expr` are used in both syntax and algebra.
`boolean`	`isConstant()` Answer whether this is a constant expression - false includes "don't know" No constant folding so "false" from an expression that evaluates to a constant
`boolean`	`isFunction()` Answer wether this is a function.
`boolean`	`isSatisfied(Binding binding, FunctionEnv execCxt)` Test whether a Constraint is satisfied, given a set of bindings Includes error propagtion and Effective Boolean Value rules.
`boolean`	`isVariable()` Answer whether this is a variable (in which case getVarName and getNodeVar can be called)
`void`	`varsMentioned(Collection<Var> acc)` Variables used by this expression - excludes variables scoped to (NOT)EXISTS
`void`	`visit(ExprVisitor visitor)`

- Field Detail
  - CMP_GREATER
```
static final int CMP_GREATER
```
    See Also:
    
    Constant Field Values
  - CMP_EQUAL
```
static final int CMP_EQUAL
```
    See Also:
    
    Constant Field Values
  - CMP_LESS
```
static final int CMP_LESS
```
    See Also:
    
    Constant Field Values
  - CMP_UNEQUAL
```
static final int CMP_UNEQUAL
```
    See Also:
    
    Constant Field Values
  - CMP_INDETERMINATE
```
static final int CMP_INDETERMINATE
```
    See Also:
    
    Constant Field Values
- Method Detail
  - isSatisfied
```
boolean isSatisfied(Binding binding,
                    FunctionEnv execCxt)
```
    Test whether a Constraint is satisfied, given a set of bindings Includes error propagtion and Effective Boolean Value rules.
    
    Parameters:
    
    binding - The bindings
    
    execCxt - FunctionEnv
    
    Returns:
    
    true or false
  - getVarsMentioned
```
Set<Var> getVarsMentioned()
```
    Variables used by this expression - excludes variables scoped to (NOT)EXISTS
  - varsMentioned
```
void varsMentioned(Collection<Var> acc)
```
    Variables used by this expression - excludes variables scoped to (NOT)EXISTS
  - eval
```
NodeValue eval(Binding binding,
               FunctionEnv env)
```
    Evaluate this expression against the binding
    
    Parameters:
    
    binding -
    
    env -
  - copySubstitute
```
Expr copySubstitute(Binding binding)
```
    Deep copy with substitution
  - applyNodeTransform
```
Expr applyNodeTransform(NodeTransform transform)
```
    Rewrite, applying a node->node transformation
  - deepCopy
```
Expr deepCopy()
```
    Deep copy
  - isVariable
```
boolean isVariable()
```
    Answer whether this is a variable (in which case getVarName and getNodeVar can be called)
  - getVarName
```
String getVarName()
```
    Variable name (returns null if not a variable)
  - getExprVar
```
ExprVar getExprVar()
```
    Variable (or null)
  - asVar
```
Var asVar()
```
    Convert to a Var variable.
  - isConstant
```
boolean isConstant()
```
    Answer whether this is a constant expression - false includes "don't know" No constant folding so "false" from an expression that evaluates to a constant
  - getConstant
```
NodeValue getConstant()
```
    NodeValue constant (returns null if not a constant)
  - isFunction
```
boolean isFunction()
```
    Answer wether this is a function.
  - getFunction
```
ExprFunction getFunction()
```
    Get the function (returns null if not a function)
  - visit
```
void visit(ExprVisitor visitor)
```
  - hashCode
```
int hashCode()
```
    Expr are used in both syntax and algebra. There is no syntax to algebra translation step because the parser uses operator precedence to build the right evaluation structure directly.
    The exceptions to this are the NOT EXISTS and EXISTS expressions which involve a query pattern. As a result there are different ways in syntax to produce the same algebra form.
    Two Expr are considered equal if they are equal as algebra expressions. hashCode and equals must implement that.
    There is also equalsBySyntax. Because two different syntax forms can yield the same algebra, but two different algebra forms must be different syntax, equalsBySyntax implies equals (by alegbra).
    Hence, different hashCode => not equalsBySyntax.
    Overrides: hashCode in class Object
  equals boolean equals(Object other) Overrides: equals in class Object equalsBySyntax boolean equalsBySyntax(Expr other) equals boolean equals(Expr other, boolean bySyntax) General equality operation - consider this to be 'protected'

Interface Expr

Field Summary

Method Summary

Field Detail

CMP_GREATER

CMP_EQUAL

CMP_LESS

CMP_UNEQUAL

CMP_INDETERMINATE

Method Detail

isSatisfied

getVarsMentioned

varsMentioned

eval

copySubstitute

applyNodeTransform

deepCopy

isVariable

getVarName

getExprVar

asVar

isConstant

getConstant

isFunction

getFunction

visit

hashCode

equals

equalsBySyntax

equals