1 Introduction In situations where a program P interacts with one or more untrusted program components U, a well-specifiedaccess control policy protects P 's resources from unwanted operations performed by U.Systems such as Java and the Common Language Runtime (CLR) provide a mechanism

Lexical and dynamic scoping are the two primary approaches to variable binding in functional programming languages. While medieval Lisp dialects commonly featured dynamic scoping, most languages today emphasize lexical scoping. This is a sensible choice: lexical scoping enables local reasoning

Obliq is a lexically-scoped untyped language that supports distributed object-oriented computation. An Obliq computation may involve multiple threads of control within an address space, multiple address spaces on a machine, heterogeneous machines over a local network, and multiple networks over

. Slots unite variables and procedures into a single construct. This permits the inheritance hierarchy to take over the function of lexical scoping in conventional languages. Finally, because SELF does not distinguish state from behavior, it narrows the gaps between ordinary objects, procedures

Abstract. Adding environments as first-class entities to a language can greatly enhance its expressiveness. But first-class environments rely on identifiers, the syntax of variables, and thus do not mesh well with lexically-scoped languages. We present first-class extents as an alternative. First

multiple source languages. Currently, it only supports Scheme, which is a lexically-scoped language in the Lisp family. The Kawa dialect of Scheme implements almost all of the current Scheme standard (R5RS), with a number of extensions, and is written in a efficient objectoriented style. It includes

in goals and the body of clauses is described. In its non-deterministic form, this interpreter is sound and complete for intuitionistic logic. Universal quantification can provide lexical scoping of individual, function, and predicate constants. Several examples are presented to show how such scoping can

. The translation of programs written in rich object languages into a small core language is defined via syntax-directed patterns. In contrast to macroexpansion and program-rewriting tools, our extensible grammars respect scoping rules. Therefore, we can introduce binding constructs while avoiding problems

to be a framework that supports multiple source languages. Currently, it only supports Scheme, which is a lexically-scoped language in the Lisp family. The Kawa dialect of Scheme implements almost all of the current Scheme standard (R 5 RS), with a number of extensions, and is written in a efficient

of the segmental system and of the rules or parameters characterizing the language, an outline of syllable structure and domains above the syllable, a discussion of lexical and postlexical phonology, an account of stress and prominence, and, if space allows, some overview of the intonational structure