net.sourceforge.czt.circus.ast

Interface ChannelDecl

All Superinterfaces:

Decl, Term

All Known Implementing Classes:

ChannelDeclImpl

public interface ChannelDecl
extends Decl

A channel declaration is a Z declaration that accepts generic types. It represents the SimpleCDeclaration grammar rule.

Channels can be declared either as typed or synchronisation. They can als have generic types or come from a previously declared schema.

The structure of the complex type associated with this class is a follows:

• Typed channels = optional generics, nonempty list of declnames, non-null Expr.
• Synch. channels = empty generics, nonempty list of declnames, RefExpr(SYNCH), where SYNCH is a given type.
• Schema channels = optional generics, empty list of declnames, non-null RefExpr.

This invariant is to be enforced by the parser, and further unfolded by the typechecker. That is, channels declared through schemas must be expanded to their typed declaration form. Such unfolding must take into account both sets of generic formals comming from the channel declaration as well as the schema generic formals. In this sense, the user is allowed to change the pattern of generic formals inside the schema through the generic formals of the channel declaration (see ./parser/tests/cirus/channels.tex for an example).

The getNameList() method contains a list of non-null NameList objects with size two. The first element is the (possibly empty) list of generic formal parameters, whereas the second element is the (possibly empty) list of declared channel names. If the second list is empty, that means the ChannelDecl represents a channelfrom (i.e., channel declaration from a schema expression found in the getExpr() method).

Author:

GnAST version 1.6-SNAPSHOT

Field Summary

Fields

Modifier and Type	Field and Description
static int	CHANNEL_GENFORMAL_INDEX
static int	CHANNEL_NAMELIST_INDEX

Method Summary

Modifier and Type	Method and Description
Expr	getExpr() Returns the Expr element.
ListTerm<NameList>	getNameList() Returns the NameList elements.
ZNameList	getZChannelNameList() This is a convenience method.
ZNameList	getZGenFormals() This is a convenience method.
void	setExpr(Expr expr) Sets the Expr element.

Methods inherited from interface net.sourceforge.czt.base.ast.Term

accept, annsSize, create, getAnn, getAnns, getChildren, hasAnn, hasAnn, removeAnn, removeAnn

Field Detail

CHANNEL_GENFORMAL_INDEX

static final int CHANNEL_GENFORMAL_INDEX

See Also:

Constant Field Values

CHANNEL_NAMELIST_INDEX

static final int CHANNEL_NAMELIST_INDEX

See Also:

Constant Field Values

Method Detail

getNameList

ListTerm<NameList> getNameList()

Returns the NameList elements.

To add or remove elements, use the methods provided by the List interface (that's why there is no need for a setter method).

Returns:

a list of NameList elements.

getExpr

Expr getExpr()

Returns the Expr element.

Returns:

the Expr element.

setExpr

void setExpr(Expr expr)

Sets the Expr element.

Parameters:

expr - the Expr element.

See Also:

getExpr()

getZGenFormals

ZNameList getZGenFormals()

This is a convenience method. It represents the non-null (possibly empty) list of generic formal parameters for this channel declaration. It returns the ZNameList from getNameList().get(0) if it is an instance of ZNameList, or throws an UnsupportedAstClassException otherwise.

getZChannelNameList

ZNameList getZChannelNameList()

This is a convenience method. It represents the non-null (possibly empty) list of declared channel names for this channel declaration. If the list is empty, this represennt a "channelfrom" declaration, where the getExpr() returns the SchExpr the delcared channels can be found. It returns the ZNameList if NameList is an instance of ZNameList or throws an UnsupportedAstClassException otherwise.