GroupElementExpression (math 2.1.0 API)

All Superinterfaces:

Expression

All Known Subinterfaces:

GroupVariableExpr

All Known Implementing Classes:

AbstractGroupElementExpression, BasicNamedGroupVariableExpr, GroupElementConstantExpr, GroupEmptyExpr, GroupInvExpr, GroupOpExpr, GroupPowExpr, PairingExpr
```
public interface GroupElementExpression
extends Expression
```
An Expression that evaluates to a GroupElement.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default GroupElement`	`evaluate()` Evaluates the expression.
`GroupElement`	`evaluate(Substitution substitutions)` Evaluates the expression after substituting contained variables.
`default GroupOpExpr`	`flatten()` Returns an equivalent expression of the form \(y \cdot \prod(g_i^{x_i})\), where \(y\) doesn't contain any variables.
`GroupOpExpr`	`flatten(ExponentExpr exponent)` Linearizes the expression \(\text{this}^\text{exponent}\).
`Group`	`getGroup()` Returns the group such that this expression evaluates to an element of this group, or null if group is unknown (for example, if expression consists only of variables).
`default GroupElementExpression`	`inv()`
`default GroupEqualityExpr`	`isEqualTo(GroupElement other)`
`default GroupEqualityExpr`	`isEqualTo(GroupElementExpression other)`
`default GroupEqualityExpr`	`isEqualTo(java.lang.String other)`
`GroupOpExpr`	`linearize()` Returns an equivalent expression of the form `y * f(groupVariables, exponentVariables)`, where `y` is constant (no variables), and the expression `f` is linear.
`default GroupElementExpression`	`op(GroupElement rhs)`
`default GroupElementExpression`	`op(GroupElementExpression rhs)`
`default GroupElementExpression`	`op(java.lang.String rhs)`
`default GroupElementExpression`	`opPow(GroupElement rhs, java.math.BigInteger exponentOfRhs)` Applies the group operation to this expression and the given group element raised to the given power.
`default GroupElementExpression`	`opPow(GroupElement rhs, ExponentExpr exponentOfRhs)` Applies the group operation to this expression and the given group element raised to the given power.
`default GroupElementExpression`	`opPow(GroupElementExpression rhs, java.math.BigInteger exponentOfRhs)` Applies the group operation to this expression and the given expression raised to the given power.
`default GroupElementExpression`	`opPow(GroupElementExpression rhs, ExponentExpr exponentOfRhs)` Applies the group operation to this expression and the given expression raised to the given power.
`default GroupElementExpression`	`opPow(GroupElementExpression rhs, java.lang.String exponentOfRhs)` Applies the group operation to this expression and the given expression raised to the given power variable.
`default GroupElementExpression`	`opPow(GroupElementExpression rhs, Zn.ZnElement exponentOfRhs)` Applies the group operation to this expression and the given expression raised to the given power.
`default GroupElementExpression`	`opPow(GroupElement rhs, java.lang.String exponentOfRhs)` Applies the group operation to this expression and the given group element raised to the given power variable.
`default GroupElementExpression`	`opPow(GroupElement rhs, Zn.ZnElement exponentOfRhs)` Applies the group operation to this expression and the given group element raised to the given power.
`default GroupElementExpression`	`pow(java.math.BigInteger exponent)`
`default GroupElementExpression`	`pow(ExponentExpr exponent)`
`default GroupElementExpression`	`pow(java.lang.Long exponent)`
`default GroupElementExpression`	`pow(RingElement exponent)`
`default GroupElementExpression`	`pow(java.lang.String exponent)`
`default GroupElementExpression`	`precompute()` Prepares this expression for more efficient evaluation by sacrificing memory instead similar to `GroupElement.precomputePow()`.
`default GroupElementExpression`	`substitute(java.lang.String variable, Expression substitution)`
`GroupElementExpression`	`substitute(Substitution substitutions)` Substitutes variables using the given function.
`default GroupElementExpression`	`substitute(VariableExpression variable, Expression substitution)` Substitutes a specific variable with the given expression.

Methods inherited from interface org.cryptimeleon.math.expressions.Expression
accumulate, containsExprMatchingPredicate, containsVariables, forEachChild, getVariables, treeWalk

- Method Detail
  - evaluate
```
default GroupElement evaluate()
```
    Description copied from interface: Expression
    
    Evaluates the expression.
    
    Specified by:
    
    evaluate in interface Expression
    
    Returns:
    
    the result of evaluation
  - evaluate
```
GroupElement evaluate(Substitution substitutions)
```
    Description copied from interface: Expression
    
    Evaluates the expression after substituting contained variables.
    
    Specified by:
    
    evaluate in interface Expression
    
    Parameters:
    
    substitutions - a function mapping variables to expressions that can be evaluated
    
    Returns:
    
    the result of evaluation
  - substitute
```
GroupElementExpression substitute(Substitution substitutions)
```
    Description copied from interface: Expression
    
    Substitutes variables using the given function.
    
    Specified by:
    
    substitute in interface Expression
    
    Parameters:
    
    substitutions - a function mapping variable expressions to their replacement expressions
    
    Returns:
    
    the expression after substitution
  - substitute
```
default GroupElementExpression substitute(java.lang.String variable,
                                          Expression substitution)
```
    Specified by:
    
    substitute in interface Expression
  - substitute
```
default GroupElementExpression substitute(VariableExpression variable,
                                          Expression substitution)
```
    Description copied from interface: Expression
    
    Substitutes a specific variable with the given expression.
    
    Specified by:
    
    substitute in interface Expression
    
    Parameters:
    
    variable - the variable to replace
    
    substitution - the expression to substitute
    
    Returns:
    
    the expression after substitution
  - op
```
default GroupElementExpression op(GroupElementExpression rhs)
```
  - op
```
default GroupElementExpression op(GroupElement rhs)
```
  - op
```
default GroupElementExpression op(java.lang.String rhs)
```
  - pow
```
default GroupElementExpression pow(ExponentExpr exponent)
```
  - pow
```
default GroupElementExpression pow(java.math.BigInteger exponent)
```
  - pow
```
default GroupElementExpression pow(java.lang.Long exponent)
```
  - pow
```
default GroupElementExpression pow(RingElement exponent)
```
  - pow
```
default GroupElementExpression pow(java.lang.String exponent)
```
  - opPow
```
default GroupElementExpression opPow(GroupElementExpression rhs,
                                     ExponentExpr exponentOfRhs)
```
    Applies the group operation to this expression and the given expression raised to the given power.
  - opPow
```
default GroupElementExpression opPow(GroupElementExpression rhs,
                                     java.math.BigInteger exponentOfRhs)
```
    Applies the group operation to this expression and the given expression raised to the given power.
  - opPow
```
default GroupElementExpression opPow(GroupElementExpression rhs,
                                     Zn.ZnElement exponentOfRhs)
```
    Applies the group operation to this expression and the given expression raised to the given power.
  - opPow
```
default GroupElementExpression opPow(GroupElementExpression rhs,
                                     java.lang.String exponentOfRhs)
```
    Applies the group operation to this expression and the given expression raised to the given power variable.
    
    Parameters:
    
    exponentOfRhs - the power variable's name
  - opPow
```
default GroupElementExpression opPow(GroupElement rhs,
                                     ExponentExpr exponentOfRhs)
```
    Applies the group operation to this expression and the given group element raised to the given power.
  - opPow
```
default GroupElementExpression opPow(GroupElement rhs,
                                     java.math.BigInteger exponentOfRhs)
```
    Applies the group operation to this expression and the given group element raised to the given power.
  - opPow
```
default GroupElementExpression opPow(GroupElement rhs,
                                     Zn.ZnElement exponentOfRhs)
```
    Applies the group operation to this expression and the given group element raised to the given power.
  - opPow
```
default GroupElementExpression opPow(GroupElement rhs,
                                     java.lang.String exponentOfRhs)
```
    Applies the group operation to this expression and the given group element raised to the given power variable.
    
    Parameters:
    
    exponentOfRhs - the power variable's name
  - inv
```
default GroupElementExpression inv()
```
  - isEqualTo
```
default GroupEqualityExpr isEqualTo(GroupElementExpression other)
```
  - isEqualTo
```
default GroupEqualityExpr isEqualTo(GroupElement other)
```
  - isEqualTo
```
default GroupEqualityExpr isEqualTo(java.lang.String other)
```
  - getGroup
```
Group getGroup()
```
    Returns the group such that this expression evaluates to an element of this group, or null if group is unknown (for example, if expression consists only of variables).
  - precompute
```
default GroupElementExpression precompute()
```
    Prepares this expression for more efficient evaluation by sacrificing memory instead similar to GroupElement.precomputePow().
    First linearizes this expression via linearize() and then calls GroupElement.precomputePow() on each GroupElementConstantExpr found in the base of each GroupPowExpr as these will be exponentiated later and can use the precomputations.
  - linearize
```
GroupOpExpr linearize()
               throws java.lang.IllegalArgumentException
```
    Returns an equivalent expression of the form y * f(groupVariables, exponentVariables), where y is constant (no variables), and the expression f is linear. Linearity means that
```
 f(groupVariables, exponentVariables) * f(groupVariables2, exponentVariables2)
 = f(groupVariables * groupVariables2, exponentVariables + exponentVariables2)
 
```
    The exact result is a GroupOpExpr where the left-hand-side y fulfills y.containsVariables() == false and the right-hand side is linear.
    Throws:
    
    java.lang.IllegalArgumentException - if it's not possible to form the desired output (e.g., the input is something like \(g^{x_1 \cdot x_2}\) for variables \(x_1, x_2\)).
  - flatten
```
default GroupOpExpr flatten()
```
    Returns an equivalent expression of the form \(y \cdot \prod(g_i^{x_i})\), where \(y\) doesn't contain any variables. The exact result is a GroupOpExpr where the left-hand side is a GroupElementConstantExpr y and the right-hand side is an expression tree where each inner nodes is a GroupOpExpr or a PairingExpr whose children are flattened.
  - flatten
```
GroupOpExpr flatten(ExponentExpr exponent)
```
    Linearizes the expression \(\text{this}^\text{exponent}\).

Interface GroupElementExpression

Method Summary

Methods inherited from interface org.cryptimeleon.math.expressions.Expression

Method Detail

evaluate

evaluate

substitute

substitute

substitute

op

op

op

pow

pow

pow

pow

pow

opPow

opPow

opPow

opPow

opPow

opPow

opPow

opPow

inv

isEqualTo

isEqualTo

isEqualTo

getGroup

precompute

linearize

flatten

flatten