asteroid

Class Expressions

java.lang.Object

asteroid.Expressions

public final class Expressions
extends java.lang.Object

This class hides the different implementations to create expressions through the Groovy api to provide a unified an easier way to create expressions when coding an AST transformation. Normally users should access this class invoking A.EXPR:

 A.EXPR.propX(owner, property)
 A.EXPR.listX(expression1, expression2)
 // ...etc
 

Since:

0.1.0

Constructor Summary

Constructors

Constructor and Description
Expressions()

Method Summary

Modifier and Type	Method and Description
static BinaryExpression	binEqX(Expression leftExpr, Expression rightExpr) Builds an instance of BinaryExpression of type AST
static BinaryExpression	binX(Expression leftExpr, int operator, Expression rightExpr) Builds a new BinaryExpression from a left expression and a right expression joined by a given operator.
static BinaryExpression	binX(java.lang.String leftVarName, int operator, java.lang.String rightVarName) Builds a new BinaryExpression with the names of the variables pointing at both left/right terms in the binary expression plus the operator in between.
BooleanExpression	boolEqualsNullX(Expression argExpr) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolHasSameFieldX(FieldNode fNode, Expression other) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolHasSamePropertyX(PropertyNode pNode, Expression other) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolIsInstanceOfX(Expression objectExpression, java.lang.Class cNode) Use it to create an "instanceof" expression to know whether an instance is of a given type or not.
BooleanExpression	boolIsInstanceOfX(Expression objectExpression, ClassNode cNode) Use it to create an "instanceof" expression to know whether an instance is of a given type or not.
BooleanExpression	boolIsOneX(Expression expr) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolIsTrueX(Expression argExpr) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolIsZeroX(Expression expr) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolNotNullX(Expression argExpr) Builds an instance of BooleanExpression of type: AST
BooleanExpression	boolSameX(Expression self, Expression other) Builds an instance of BooleanExpression of type: AST
static BooleanExpression	boolX(Expression expr) Builds an instance of BooleanExpression from a Expression passed as argument.
static BooleanExpression	boolX(Expression leftExpr, int tokenType, Expression rightExpr) When creating BooleanExpression in places such as IfStatement you can use this method to create a BooleanExpression out of a binary expression using constant expressions AST
static BooleanExpression	boolX(java.lang.String leftVarName, int tokenType, java.lang.String rightVarName) When creating BooleanExpression in places such as IfStatement you can use this method to create a BooleanExpression out of a binary expression using the names of the compared variables.
static MethodCallExpression	callSuperX(java.lang.String methodName) Creates a method call expression AST
static MethodCallExpression	callSuperX(java.lang.String methodName, Expression... args) Creates a method call expression AST
static MethodCallExpression	callThisX(java.lang.String methodName, Expression... args) Creates a method call expression using `this` as target instance AST
static MethodCallExpression	callX(Expression receiver, java.lang.String methodName, Expression... args) Creates a method call expression AST
static ClassExpression	classX(java.lang.Class clazz) Creates an instance of ClassExpression from a Class AST
static ClassExpression	classX(ClassNode classNode) Creates a class expression from a ClassNode AST
static ClosureExpression	closureX(Statement stmt, Parameter... params) Creates a closure expression.
static ConstantExpression	constX(java.lang.Object constant) Builds an instance of ConstantExpression from the constant value passed as argument AST
static FieldExpression	fieldX(FieldNode fieldNode) Creates a method call expression AST
static BooleanExpression	landX(Expression leftExpr, Expression rightExpr) Builds a binary expression using a logical and (&&) AST
static ListExpression	listX(Expression... expressions) Creates an instance of ListExpression: AST:
static BooleanExpression	lorX(Expression leftExpr, Expression rightExpr) Builds a binary expression using a logical or (||) AST
static MapEntryExpression	mapEntryX(Expression key, Expression value) Creates an instance of type MapEntryExpression
static MapExpression	mapX(java.util.List<MapEntryExpression> expressions) Creates an instance of MapExpression: AST
static MapExpression	mapX(MapEntryExpression... expressions) Creates an instance of MapExpression: AST
static ConstructorCallExpression	newX(java.lang.Class type) AST
static ConstructorCallExpression	newX(java.lang.Class type, Expression... expressions) AST
static NotExpression	notX(Expression expression) Negates a given expression AST
static PropertyExpression	propX(Expression owner, Expression property) Builds an instance of PropertyExpression: AST:
static MethodCallExpression	safeCallX(Expression receiver, java.lang.String methodName, Expression... args) Creates a safe method call expression.
static StaticMethodCallExpression	staticCallX(ClassNode clazz, java.lang.String methodName, Expression... args) Creates a static method expression AST
static StaticMethodCallExpression	staticCallX(java.lang.Class clazz, java.lang.String methodName, Expression... args) Creates a static method expression AST
static DeclarationExpression	varDeclarationX(java.lang.String varName, java.lang.Class type, Expression defaultValue) Creates a variable definition expression.
static DeclarationExpression	varDeclarationX(java.lang.String varName, ClassNode type, Expression defaultValue) Creates a variable definition expression.
static VariableExpression	varX(java.lang.String varName) Creates a reference to a given variable Creates a method call expression AST
static VariableExpression	varX(java.lang.String varName, ClassNode type) Creates a reference to a given variable Creates a method call expression AST

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Expressions

public Expressions()

Method Detail

boolX

public static BooleanExpression boolX(Expression expr)

Builds an instance of BooleanExpression from a Expression passed as argument.

AST

 boolX(expr); // imagine expression is 1 == 1
 

Result

 1 == 1 // as a boolean expression
 

Parameters:

expr - the expression we want to evaluate as true or false

Returns:

an instance of BooleanExpression

Since:

0.1.5

See Also:

binEqX(org.codehaus.groovy.ast.expr.Expression, org.codehaus.groovy.ast.expr.Expression), Types.COMPARE_EQUAL

boolEqualsNullX

public BooleanExpression boolEqualsNullX(Expression argExpr)

Builds an instance of BooleanExpression of type:

AST

 boolEqualsNullX(constX("some"));
 

Result

 "some" == null // as a boolean expression
 

Parameters:

argExpr - the operand we want to check

Returns:

an instance of BooleanExpression

Since:

0.1.5

See Also:

Types.COMPARE_EQUAL

boolHasSameFieldX

public BooleanExpression boolHasSameFieldX(FieldNode fNode,
                                           Expression other)

Builds an instance of BooleanExpression of type:

AST

 boolHasSameFieldX(personNameFieldNode, anotherPersonRef);
 

Result

 name is (peter.name) // as a boolean expression
 

Parameters:

fNode - the node we would like to check

other - Another expression having as a result another field we would like to check against

Returns:

an instance of BooleanExpression

Since:

0.1.5

boolHasSamePropertyX

public BooleanExpression boolHasSamePropertyX(PropertyNode pNode,
                                              Expression other)

Builds an instance of BooleanExpression of type:

AST

 boolHasSamePropertyX(personNamePropertyNode, anotherPersonRef);
 

Result

 name is (peter.name) // as a boolean expression
 

Parameters:

pNode - the node we would like to check

other - Another expression having as a result another property we would like to check against

Returns:

an instance of BooleanExpression

Since:

0.1.5

boolIsInstanceOfX

public BooleanExpression boolIsInstanceOfX(Expression objectExpression,
                                           ClassNode cNode)

Use it to create an "instanceof" expression to know whether an instance is of a given type or not. Builds an instance of BooleanExpression of type:

AST

 boolIsInstanceOfX(stringExpression, stringClassNode);
 

Result

 "hello" instanceof String // as a boolean expression
 

Parameters:

objectExpression - expression to evaluate

cNode - a ClassNode

Returns:

an instance of BooleanExpression

Since:

0.1.5

boolIsInstanceOfX

public BooleanExpression boolIsInstanceOfX(Expression objectExpression,
                                           java.lang.Class cNode)

Use it to create an "instanceof" expression to know whether an instance is of a given type or not. Builds an instance of BooleanExpression of type:

AST

boolIsInstanceOfX(stringExpression, stringClass)

Result

"hello" instanceof String // as a boolean expression

WARNING!: Bear in mind that a given class might not be available when using it in an AST transformation.

Parameters:

objectExpression - expression to evaluate

cNode - a Class. This

Returns:

an instance of BooleanExpression

Since:

0.1.5

boolIsOneX

public BooleanExpression boolIsOneX(Expression expr)

Builds an instance of BooleanExpression of type:

AST

 boolIsOneX(numberExpression);
 

Result

 10 == 1 // as a boolean expression
 

Utility class to check a given expression equals to the constant expression 1.

Parameters:

expr - expression to check against 1

Returns:

an instance of BooleanExpression

Since:

0.1.5

See Also:

Types.COMPARE_EQUAL

boolIsTrueX

public BooleanExpression boolIsTrueX(Expression argExpr)

Builds an instance of BooleanExpression of type:

AST

 boolIsTrueX(anyExpression);
 

Result

 "something" == Boolean.TRUE // as a boolean expression or...
 (1 == 1) == Boolean.TRUE
 

Utility class to check a given expression equals to true

Parameters:

argExpr - expression checked to be true

Returns:

an instance of BooleanExpression

Since:

0.1.5

boolIsZeroX

public BooleanExpression boolIsZeroX(Expression expr)

Builds an instance of BooleanExpression of type:

AST

 boolIsZeroX(numberExpression);
 

Result

 10 == 0 // as a boolean expression
 

Utility class to check a given expression equals to the constant expression 0.

Parameters:

expr - expression to check against 0

Returns:

an instance of BooleanExpression

Since:

0.1.5

See Also:

Types.COMPARE_EQUAL

boolNotNullX

public BooleanExpression boolNotNullX(Expression argExpr)

Builds an instance of BooleanExpression of type:

AST

 boolEqualsNotNullX(constX("some"));
 

Result

 "some" != null // as a boolean expression
 

Parameters:

argExpr - the expression we want to check

Returns:

an instance of BooleanExpression

Since:

0.1.5

See Also:

Types.COMPARE_EQUAL

boolSameX

public BooleanExpression boolSameX(Expression self,
                                   Expression other)

Builds an instance of BooleanExpression of type:

AST

 boolSameX(self, another)
 

Result

 thisInstance is otherInstance
 

Use it to create expressions asking whether a given instance is the same as another (like the == operator used in Java).

Parameters:

self - the expression we want to check against

other - another expression

Returns:

an instance of BooleanExpression answering whether a given instance is the same as another.

Since:

0.1.5

See Also:

Types

binEqX

public static BinaryExpression binEqX(Expression leftExpr,
                                      Expression rightExpr)

Builds an instance of BinaryExpression of type

AST

 binEqX(constX(1), constX(1));
 

Result

1 == 1

Parameters:

leftExpr - left hand side operand

rightExpr - right hand side operand

Returns:

an instance of BinaryExpression representing an equals expression

Since:

0.1.5

See Also:

Types.COMPARE_EQUAL

constX

public static ConstantExpression constX(java.lang.Object constant)

Builds an instance of ConstantExpression from the constant value passed as argument

AST

 callThisX("println",
     constX("1") // constant value "1"
 )
 

Result

println "1" // print constant value "1"

Parameters:

constant - the constant value

Returns:

an instance of ConstantExpression

Since:

0.1.0

propX

public static PropertyExpression propX(Expression owner,
                                       Expression property)

Builds an instance of PropertyExpression:

AST:

propX("this", constX("name"))

Result:

this.name

Parameters:

owner - the instance the property belongs to

property -

Returns:

an instance of PropertyExpression

Since:

0.1.0

listX

public static ListExpression listX(Expression... expressions)

Creates an instance of ListExpression:

AST:

listX(constX(1), constX(2))

Result:

[1,2]

Parameters:

expressions - list items as expressions

Returns:

an instance of ListExpression

Since:

0.1.0

mapX

public static MapExpression mapX(MapEntryExpression... expressions)

Creates an instance of MapExpression:

AST

mapX(mapEntryX(constX('key'), constX('value')))

Result

[key: 'value']

Parameters:

expressions - different map entries as MapEntryExpression

Returns:

an instance of MapExpression

Since:

0.2.8

mapX

public static MapExpression mapX(java.util.List<MapEntryExpression> expressions)

Creates an instance of MapExpression:

AST

mapX(mapEntryX(constX('key'), constX('value')))

Result

[key: 'value']

Parameters:

expressions - different map entries as MapEntryExpression

Returns:

an instance of MapExpression

Since:

0.2.8

mapEntryX

public static MapEntryExpression mapEntryX(Expression key,
                                           Expression value)

Creates an instance of type MapEntryExpression

Parameters:

key - an Expression as the map entry key

value - an Expression as the map entry value

Returns:

an instance of MapEntryExpression

Since:

0.2.8

classX

public static ClassExpression classX(java.lang.Class clazz)

Creates an instance of ClassExpression from a Class

AST

classX(String.class)

Result

String.class

Parameters:

clazz -

Returns:

an instance of ClassExpression

Since:

0.1.0

classX

public static ClassExpression classX(ClassNode classNode)

Creates a class expression from a ClassNode

AST

classX(A.NODES.clazz(String.class))

Result

String.class

Parameters:

classNode -

Returns:

an instance of ClassNode

Since:

0.1.0

callThisX

public static MethodCallExpression callThisX(java.lang.String methodName,
                                             Expression... args)

Creates a method call expression using `this` as target instance

AST

A.NODES.callThisX("println", A.EXPR.constX("hello"))

Result

println "hello"

Parameters:

methodName - The name of the method to invoke

args - with different argument expressions

Returns:

an instance of MethodCallExpression

Since:

0.1.0

callX

public static MethodCallExpression callX(Expression receiver,
                                         java.lang.String methodName,
                                         Expression... args)

Creates a method call expression

AST

A.NODES.callX(ownerExpression, "toMD5", A.EXPR.constX("hello"))

Result

owner.toMD5("hello")

Parameters:

receiver - target instance expression

methodName - The name of the method to invoke

args - with different argument expressions

Returns:

an instance of MethodCallExpression

Since:

0.1.0

safeCallX

public static MethodCallExpression safeCallX(Expression receiver,
                                             java.lang.String methodName,
                                             Expression... args)

Creates a safe method call expression. It will return null if the receiver object is null.

AST

A.NODES.safeCallX(ownerExpression, "toMD5", A.EXPR.constX("hello"))

Result

owner?.toMD5("hello")

Parameters:

receiver - target instance expression

methodName - The name of the method to invoke

args - with different argument expressions

Returns:

an instance of MethodCallExpression

Since:

0.1.3

staticCallX

public static StaticMethodCallExpression staticCallX(ClassNode clazz,
                                                     java.lang.String methodName,
                                                     Expression... args)

Creates a static method expression

AST

A.NODES.staticCallX(systemClassNode, "currentTimeMillis")

Result

System.currentTimeMillis()

Parameters:

clazz - the ClassNode the method belongs

methodName - The name of the method to invoke

args - with different argument expressions

Returns:

an instance of StaticMethodCallExpression

Since:

0.1.0

staticCallX

public static StaticMethodCallExpression staticCallX(java.lang.Class clazz,
                                                     java.lang.String methodName,
                                                     Expression... args)

Creates a static method expression

AST

A.NODES.staticCallX(systemClass, "currentTimeMillis")

Result

System.currentTimeMillis()

Parameters:

clazz - the Class the method belongs

methodName - The name of the method to invoke

args - with different argument expressions

Returns:

an instance of StaticMethodCallExpression

Since:

0.1.0

fieldX

public static FieldExpression fieldX(FieldNode fieldNode)

Creates a method call expression

AST

     
         class A {
             Integer age
         }
         //...
         FieldExpression node = A.NODES.fieldX(ageNode)
         A.EXPR.callX(node, "toString")
     
 

Result

age.toString()

Parameters:

fieldNode - the node pointing at the field

Returns:

an instance of FieldExpression

Since:

0.1.0

callSuperX

public static MethodCallExpression callSuperX(java.lang.String methodName)

Creates a method call expression

AST

     
         class A {
             public void doSomething() {
                 super.doSomething()
             }
         }

         //...
         MethodCallExpression = A.NODES.callSuperX("doSomething")

     
 

Result

super.doSomething()

Parameters:

methodName - name of the method we want to call

Returns:

an instance of MethodCallExpression

Since:

0.1.0

callSuperX

public static MethodCallExpression callSuperX(java.lang.String methodName,
                                              Expression... args)

Creates a method call expression

AST

     
         class A {
             public void doSomething(String constant) {
                 super.doSomething("1")
             }
         }

         //...
         MethodCallExpression = A.NODES.callSuperX("doSomething", constX("1"))

     
 

Result

super.doSomething("1")

Parameters:

methodName - name of the method we want to call

args - expression representing different arguments to method call expression

Returns:

an instance of MethodCallExpression

Since:

0.1.0

varX

public static VariableExpression varX(java.lang.String varName)

Creates a reference to a given variable Creates a method call expression

AST

     
         class A {
             public void doSomething(String constant) {
                 super.doSomething(constant)
             }
         }

         //...
         VariableExpression = A.NODES.varX("constant")

     
 

Result

constant

Parameters:

varName -

Returns:

an instance of VariableExpression

Since:

0.1.0

varX

public static VariableExpression varX(java.lang.String varName,
                                      ClassNode type)

Creates a reference to a given variable Creates a method call expression

AST

     
         class A {
             public void doSomething(String constant) {
                 super.doSomething(constant)
             }
         }

         //...
         VariableExpression = A.NODES.varX("constant", A.NODES.clazz(String))

     
 

Result

constant

Creates a reference to a given variable

Parameters:

varName -

type -

Returns:

an instance of VariableExpression

Since:

0.1.0

closureX

public static ClosureExpression closureX(Statement stmt,
                                         Parameter... params)

Creates a closure expression. The statement passed as first parameter becomes the closure's body.

AST

 closureX(returnS(constantX("hello"))) // without params
 closureX(statement, param("n",Integer)) // with a param
 

Result

 { -> "hello" } // without params
 { Integer n -> n + 1 } // n + 1 is the statement
 

Parameters:

stmt - the body of the closure

params - the closure parameters

Returns:

an instance of ClosureExpression

Since:

0.1.5

boolX

public static BooleanExpression boolX(java.lang.String leftVarName,
                                      int tokenType,
                                      java.lang.String rightVarName)

When creating BooleanExpression in places such as IfStatement you can use this method to create a BooleanExpression out of a binary expression using the names of the compared variables. AST

 //...after declaring the variables somewhere
 boolX('johnAge', Types.COMPARE_GREATER_THAN, 'peterAge')
 

Result

 johnAge > peterAge
 

Parameters:

leftVarName - name of the variable referenced in the left side of the binary expression

tokenType - type of the comparison operator. Use any of the listed in Types

rightVarName - name of the variable referenced in the right side of the binary expression

Returns:

a boolean expression as a BooleanExpression instance

Since:

0.2.4

boolX

public static BooleanExpression boolX(Expression leftExpr,
                                      int tokenType,
                                      Expression rightExpr)

When creating BooleanExpression in places such as IfStatement you can use this method to create a BooleanExpression out of a binary expression using constant expressions AST

 //...after declaring the variables somewhere
 boolX(constX(4), Types.COMPARE_GREATER_THAN, 2)
 

Result

 4 > 2
 

Parameters:

leftExpr - left expression

tokenType - type of the comparison operator. Use any of the listed in Types

rightExpr - right expression

Returns:

a boolean expression as a BooleanExpression instance

Since:

0.2.4

binX

public static BinaryExpression binX(java.lang.String leftVarName,
                                    int operator,
                                    java.lang.String rightVarName)

Builds a new BinaryExpression with the names of the variables pointing at both left/right terms in the binary expression plus the operator in between. The operator can be anyone found in the Types type AST

 //...after declaring the variables somewhere
 boolX('johnAge', Types.PLUS, 'peterAge')
 

Result

 johnAge + peterAge
 

Parameters:

leftVarName - name of the variable referenced in the left side of the binary expression

operator - type of the operator. Use any of the listed in Types

rightVarName - name of the variable referenced in the right side of the binary expression

Returns:

a binary expression as a BinaryExpression instance

Since:

0.2.4

binX

public static BinaryExpression binX(Expression leftExpr,
                                    int operator,
                                    Expression rightExpr)

Builds a new BinaryExpression from a left expression and a right expression joined by a given operator. The operator can be anyone found in the Types type AST

 //...after declaring the variables somewhere
 binX('johnAge', Types.PLUS, 'peterAge')
 

Result

 johnAge + peterAge
 

Parameters:

leftExpr - left term in the binary expression side of the binary expression

operator - type of the comparison operator. Use any of the listed in Types

rightExpr - right term in the binary expression

Returns:

a binary expression as a BinaryExpression instance

Since:

0.2.4

varDeclarationX

public static DeclarationExpression varDeclarationX(java.lang.String varName,
                                                    ClassNode type,
                                                    Expression defaultValue)

Creates a variable definition expression. Where, in the code a variable is defined. If could be also initialized. AST

 //...after declaring the variables somewhere
 varDeclarationX('johnAge',
                  A.NODES.clazz(Integer).build(),
                  A.EXPR.constX(23))
 

Result

 Integer johnAge = 23
 

Parameters:

varName - name of the declared variable

type - type of the declared variable as a ClassNode instance

defaultValue - expression setting the default value of the declared variable

Returns:

an instance of a DeclarationExpression

Since:

0.2.4

varDeclarationX

public static DeclarationExpression varDeclarationX(java.lang.String varName,
                                                    java.lang.Class type,
                                                    Expression defaultValue)

Creates a variable definition expression. Where, in the code a variable is defined. If could be also initialized. AST

 //...after declaring the variables somewhere
 varDeclarationX('johnAge', Integer, A.EXPR.constX(23))
 

Result

 Integer johnAge = 23
 

Parameters:

varName - name of the declared variable

type - type of the declared variable as a Class instance

defaultValue - expression setting the default value of the declared variable

Returns:

an instance of a DeclarationExpression

Since:

0.2.4

newX

public static ConstructorCallExpression newX(java.lang.Class type)

AST

 newX(ArrayList)
 

Result

 new ArrayList()
 

Parameters:

type - type of the target object

Returns:

an instance of ConstructorCallExpression

Since:

0.2.4

newX

public static ConstructorCallExpression newX(java.lang.Class type,
                                             Expression... expressions)

AST

 newX(File, varX('path'), constX('myfile.txt'))
 

Result

 new File(path, 'myfile.txt')
 

Parameters:

type - type of the target object

expressions - a varargs of type Expression

Returns:

an instance of ConstructorCallExpression

Since:

0.2.4

notX

public static NotExpression notX(Expression expression)

Negates a given expression AST

 notX(varX('myVariable'))
 

Result

 !myVariable
 

Parameters:

expression - the expression to be negated

Returns:

the expression passed as parameter negated

Since:

0.2.4

lorX

public static BooleanExpression lorX(Expression leftExpr,
                                     Expression rightExpr)

Builds a binary expression using a logical or (||) AST

 lorX(varX('a'), varX('b'))
 

Result

 a || b
 

Parameters:

leftExpr -

rightExpr -

Returns:

a BooleanExpression representing a logical OR (||)

Since:

0.2.4

landX

public static BooleanExpression landX(Expression leftExpr,
                                      Expression rightExpr)

Builds a binary expression using a logical and (&&) AST

 landX(varX('a'), varX('b'))
 

Result

 a && b
 

Parameters:

leftExpr -

rightExpr -

Returns:

a BooleanExpression representing a logical AND (&&)

Since:

0.2.4