jfun.jaskell
Interface Resolver

All Known Implementing Classes:

DefaultResolver, EitherResolver, NilResolver

public interface Resolver

This interface is responsible for resolving unbound variables, object members and subscript expressions (like a[1]).

When a resolution fails, implementation returns the default value. That means,

def==resolveVar(name, def)

can be used to test whether a resolution succeeded.

Jaskell.setResolver(Resolver) can be used to associate a Resolver instance to a jaskell runtime.

Author:

Ben Yu Feb 17, 2006 11:22:24 AM

Method Summary

java.lang.Object	resolveMember(java.lang.Object obj, java.lang.String name, java.lang.Object def) Resolve a tuple member.
java.lang.Object	resolveSubscript(java.lang.Object obj, java.lang.Object[] args, java.lang.Object def) Resolve a subscript expression.
java.lang.Object	resolveVar(java.lang.String name, java.lang.Object def) Resolve a variable.

Method Detail

resolveVar

java.lang.Object resolveVar(java.lang.String name,
                            java.lang.Object def)

Resolve a variable.

Parameters:

name - the variable name.

def - the default value.

Returns:

the variable value or the default value if not resolveable.

resolveMember

java.lang.Object resolveMember(java.lang.Object obj,
                               java.lang.String name,
                               java.lang.Object def)

Resolve a tuple member.

Parameters:

obj - the object.

name - the member name.

def - the default value.

Returns:

the member value or the default value if not resolveable.

resolveSubscript

java.lang.Object resolveSubscript(java.lang.Object obj,
                                  java.lang.Object[] args,
                                  java.lang.Object def)

Resolve a subscript expression.

Parameters:

obj - the object.

args - the subscripts.

def - the default value.

Returns:

the result or the default value if not resolveable.