edu.uiowa.cs.clc.kind2.lustre

Class ContractBodyBuilder

java.lang.Object

edu.uiowa.cs.clc.kind2.lustre.ContractBodyBuilder

public class ContractBodyBuilder
extends java.lang.Object

This class provides helper functions for constructing a contract body which can be embedded in a node's/function's inline contract or an external contract node. The body is composed of items, each of which define

• a ghost variable / constant,
• an assumption,
• a guarantee,
• a mode, or
• an import of a contract node.

Constructor Summary

Constructors

Constructor and Description
ContractBodyBuilder() Constructor

Method Summary

Modifier and Type	Method and Description
void	addMode(ModeBuilder modeBuilder) Add a mode
void	assume(Expr expr) Add an assumption.
void	assume(java.lang.String name, Expr expr) Add an assumption.
IdExpr	createConstant(java.lang.String name, Expr expr) Create a ghost constant.
IdExpr	createConstant(java.lang.String name, Type type) Create a ghost constant.
IdExpr	createConstant(java.lang.String name, Type type, Expr expr) Create a ghost constant.
IdExpr	createVarDef(java.lang.String name, Type type, Expr expr) Create a ghost variable.
void	guarantee(Expr expr) Add a guarantee.
void	guarantee(java.lang.String name, Expr expr) Add a guarantee.
void	importContract(java.lang.String id, java.util.List<Expr> inputs, java.util.List<IdExpr> outputs) Import a contract.
void	weaklyAssume(Expr expr) Add a a weakly assume.
void	weaklyAssume(java.lang.String name, Expr expr) Add a weakly assume.
void	weaklyGuarantee(Expr expr) Add a guarantee.
void	weaklyGuarantee(java.lang.String name, Expr expr) Add a weakly guarantee.

Methods inherited from class java.lang.Object

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

Constructor Detail

ContractBodyBuilder

public ContractBodyBuilder()

Constructor

Method Detail

createConstant

public IdExpr createConstant(java.lang.String name,
                             Type type)

Create a ghost constant. A ghost constant is a stream that is local to the contract. That is, it is not accessible from the body of the node specified.

Parameters:

name - name of ghost constant

type - type of ghost constant

Returns:

an expression referring to created ghost constant

createConstant

public IdExpr createConstant(java.lang.String name,
                             Expr expr)

Create a ghost constant. A ghost constant is a stream that is local to the contract. That is, it is not accessible from the body of the node specified.

Parameters:

name - name of ghost constant

expr - expression specifying value assigned to ghost constant

Returns:

an expression referring to created ghost constant

createConstant

public IdExpr createConstant(java.lang.String name,
                             Type type,
                             Expr expr)

Create a ghost constant. A ghost constant is a stream that is local to the contract. That is, it is not accessible from the body of the node specified.

Parameters:

name - name of ghost constant

type - type of ghost constant

expr - expression specifying value assigned to ghost constant

Returns:

an expression referring to created ghost constant

createVarDef

public IdExpr createVarDef(java.lang.String name,
                           Type type,
                           Expr expr)

Create a ghost variable. A ghost variable is a stream that is local to the contract. That is, it is not accessible from the body of the node specified.

Parameters:

name - name of ghost variable

type - type of ghost variable

expr - expression specifying stream of values assigned to ghost variable

Returns:

an expression referring to created ghost variable

assume

public void assume(Expr expr)

Add an assumption. An assumption over a node n is a constraint one must respect in order to use n legally. It cannot mention the outputs of n in the current state, but referring to outputs under a pre is fine.

Parameters:

expr - an expression representing a constraint

assume

public void assume(java.lang.String name,
                   Expr expr)

Add an assumption. An assumption over a node n is a constraint one must respect in order to use n legally. It cannot mention the outputs of n in the current state, but referring to outputs under a pre is fine.

Parameters:

name - name of the assumption

expr - an expression representing a constraint

weaklyAssume

public void weaklyAssume(Expr expr)

Add a a weakly assume. An assumption over a node n is a constraint one must respect in order to use n legally. It cannot mention the outputs of n in the current state, but referring to outputs under a pre is fine. Use this function if you are interested in computing an IVC among a subset of the assumptions.

Parameters:

expr - an expression representing a constraint

weaklyAssume

public void weaklyAssume(java.lang.String name,
                         Expr expr)

Add a weakly assume. An assumption over a node n is a constraint one must respect in order to use n legally. It cannot mention the outputs of n in the current state, but referring to outputs under a pre is fine. Use this function if you are interested in computing an IVC among a subset of the assumptions.

Parameters:

name - name of the assumption

expr - an expression representing a constraint

guarantee

public void guarantee(Expr expr)

Add a guarantee. Unlike assumptions, guarantees do not have any restrictions on the streams they can mention. They typically mention the outputs in the current state since they express the behavior of the node they specified under the assumptions of this node.

Parameters:

expr - constraint expressing the behavior of a node

guarantee

public void guarantee(java.lang.String name,
                      Expr expr)

Add a guarantee. Unlike assumptions, guarantees do not have any restrictions on the streams they can mention. They typically mention the outputs in the current state since they express the behavior of the node they specified under the assumptions of this node.

Parameters:

name - name of the guarantee

expr - constraint expressing the behavior of a node

weaklyGuarantee

public void weaklyGuarantee(Expr expr)

Add a guarantee. Unlike assumptions, guarantees do not have any restrictions on the streams they can mention. They typically mention the outputs in the current state since they express the behavior of the node they specified under the assumptions of this node. Use this function if you are interested in computing an IVC among a subset of the guarantees.

Parameters:

expr - constraint expressing the behavior of a node

weaklyGuarantee

public void weaklyGuarantee(java.lang.String name,
                            Expr expr)

Add a weakly guarantee. Unlike assumptions, guarantees do not have any restrictions on the streams they can mention. They typically mention the outputs in the current state since they express the behavior of the node they specified under the assumptions of this node. Use this function if you are interested in computing an IVC among a subset of the guarantees.

Parameters:

name - name of the guarantee

expr - constraint expressing the behavior of a node

addMode

public void addMode(ModeBuilder modeBuilder)

Add a mode

Parameters:

modeBuilder - a mode builder

importContract

public void importContract(java.lang.String id,
                           java.util.List<Expr> inputs,
                           java.util.List<IdExpr> outputs)

Import a contract. A contract import merges the current contract with the one imported. That is, if the current contract is (A,G,M) and we import (A',G',M'), the resulting contract is (A U A', G U G', M U M') where U is set union.

When importing a contract, it is necessary to specify how the instantiation of the contract is performed. This defines a mapping from the input (output) formal parameters to the actual ones of the import.

When importing contract c in the contract of node n, it is illegal to mention an output of n in the actual input parameters of the import of c.

Parameters:

id - name of contract to import

inputs - inputs to the contract

outputs - outputs of the contract