Vasconcelos, V. T. and K. Honda, Principal typing schemes in a polyadic picalculus, in: Proceedings of the 4th International Conference on Concurrency  Home/Search   Document Not in Database   Summary   Related Articles   Check

....more pragmatic requirement that well typedness must be automatically and efficiently verifiable. Milner s sort discipline plays an essential role in later papers on properties of the calculus [Wal92, San92] it has been further studied by Turner [Tur94] Gay [Gay93] and Vasconcelos and Honda [VH93], who consider the problem of inferring most general sortings. Our typing discipline retains the basic character of Milner s, while extending it in two dimensions. First, we replace by name matching of sorts with the more straightforward notion of structural matching, a technical modification ....

....theoretical properties of our type system rather than to propose a pragmatic notation for programming, we adopt an explicitly typed presentation in which every bound name is annotated with a sorting. The algorithmic problem of inferring these annotations is deferred to future investigation (c.f. [Tur94, Gay93, VH93]) Our basic syntactic categories are defined by the grammar in Figure 1. We use the metavariables S, T , and U for sorts; P , Q, and R for process expressions; Gamma and Delta for sorting assumptions (or sortings) and a, b, c, etc. for channels (or names) For most of the paper, the only type ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....at run time. Given the relative rarity of these constructs in our programs, we choose not to provide this degree of fairness in the Pict library implementing choice. 3 Type System The Pict type system has its roots in the theoretical literature on type systems for the calculus [Mil91, Gay93, VH93, PS93, Tur96] and for functional languages, among which its most immediate predecessors are Quest [Car91] and Amber [Car86] The treatment of subtyping and higher order polymorphism is based on recent work on static type systems for object oriented languages [Car84, Bru94, CHC90, PT94, HP95, ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....was generally successful. A good example is Turner s work on the polymorphic # calculus [Tur95] whose semantic properties are also thoroughly examined by Pierce and Sangiorgi [PS00] concurrent calculi with a weaker form of parametric polymorphism were also developed in earlier studies [Gay93, VH93] The second case, subtype polymorphism, has been almost as extensively studied. It is well understood in various forms (e.g. deep subtyping versus shallow subtyping with different tradeoffs) and it was also incorporated in type systems for concurrent calculi. Examples of such work are ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR

....was generally successful. A good example is Turner s work on the polymorphic # calculus [Tur95] whose semantic properties are also thoroughly examined by Pierce and Sangiorgi [PS00] concurrent calculi with a weaker form of parametric polymorphism were also developed in earlier studies [Gay93, VH93] The second case, subtype polymorphism, has been almost as extensively studied. It is well understood in various forms (e.g. deep subtyping versus shallow subtyping with different tradeoffs) and it was also incorporated in type systems for concurrent calculi. Examples of such work are ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR

....was generally successful. A good example is Turner s work on the polymorphic calculus [Tur95] whose semantic properties are also thoroughly examined by Pierce and Sangiorgi [PS00] concurrent calculi with a weaker form of parametric polymorphism were also developed in earlier studies [Gay93, VH93] The second case, subtype polymorphism, has been almost as extensively studied. It is well understood in various forms (e.g. deep subtyping versus shallow subtyping with different tradeoffs) and it was also incorporated in type systems for concurrent calculi. Examples of such work are ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR 1993, vol. 715 of LNCS, pp. 524--538. Springer-Verlag, 1993.

....was generally successful. A good example is Turner s work on the polymorphic calculus [Tur95] whose semantic properties are also thoroughly examined by Pierce and Sangiorgi [PS00] concurrent calculi with a weaker form of parametric polymorphism were also developed in earlier studies [Gay93, VH93] The second case, subtype polymorphism, has been almost as extensively studied. It is well understood in various forms (e.g. deep subtyping versus shallow subtyping with different tradeoffs) and it was also incorporated in type systems for concurrent calculi. Examples of such work are ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR 1993, vol. 715 of LNCS, pp. 524--538. Springer-Verlag, 1993.

....was generally successful. A good example is Turner s work on the polymorphic calculus [Tur95] whose semantic properties are also thoroughly examined by Pierce and Sangiorgi [PS00] concurrent calculi with a weaker form of parametric polymorphism were also developed in earlier studies [Gay93, VH93] The second case, subtype polymorphism, has been almost as extensively studied. It is well understood in various forms (e.g. deep subtyping versus shallow subtyping with different tradeoffs) and it was also incorporated in type systems for concurrent calculi. Examples of such work are ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR 1993, vol. 715 of LNCS, pp. 524--538. Springer-Verlag, 1993.

....all reasons for oe 6 if seq ( ae seq (oe) A type ae not satisfying the conditions of Def. 7 is constructed for each reason [16] ut 5 Related Work Most work on types in concurrent systems is based on Milner s calculus [8, 7] and similar calculi. The problems of inferring most general types [4, 19] and subtyping [11, 12, 18, 3, 17] were considered. But these type systems cannot represent message sequences and ensure statically that all sent messages are acceptable. A large amount of work based on path expressions and process algebra shows that reasoning about the order of messages in ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic picalculus. In Proceedings CONCUR'93, July 1993.

....programming languages: labeled records, integers, booleans, and so on. These are all included in the syntax and typing rules listed in the appendices. Some other useful extensions, such as subtyping, recursive types, and polymorphism, are described (in various combinations) in the literature (c.f. [Mil89, Gay93, PS93, VH93, Tur93]) Indeed, recent work on static type systems for sequential objectoriented languages (c.f. Car88, Bru93, PT93] indicates that a general treatment of the object oriented features that we introduce in Section 7 might be based on a combination of all of these features. 4 Process Typing A type ....

....simple theorem stating that a well formed process cannot immediately misbehave : Theorem: If Delta P and P P 0 (P reduces to P 0 ) then Delta P 0 . Theorem: If Delta P then P s next step cannot result in a run time type failure. Formal proofs of these theorems can be found in [VH93] for a system extended with recursive types. Proofs for a system including both recursive types and polymorphism appear in [Tur93] and for a system with recursive types and subtyping in [PS93] As in the simply typed calculus, simply typed calculus processes have principal types [Gay93, Tur93, ....

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Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....much more complicated than polymorphic types in our system. CHAPTER 10. RELATED WORK 163 3. Once one has a sufficiently powerful polymorphic type system, it is possible to distinguish values of isomorphic type using the abstract datatype encodings presented in Section 5.7. Vasconcelos and Honda [VH93] have independently proposed a monomorphic type system for the polyadic calculus which is very similar to ours (except that they treat recursive types in a more traditional way, interpreting recursive types as regular trees) They prove that their type system is sound and has the principal type ....

....ffi ffi 0 ffi ffi 0 c : fname : String ; age : Intg P c : fname : String ; age : Intg c fname = Daveg:P The Pict type system [PT95b] uses Pierce and Sangiorgi s channel subtyping, as well as subtyping for record values and patterns. 10.2 Type inference Vasconcelos and Honda [VH93] have independently developed a type inference algorithm very similar to the one presented here. Their algorithm, takes only a process P as argument, and constructs the principal context in which P is well formed. We can easily derive a similar algorithm from our type inference algorithm X: ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....between the polymorphic pi and lambda calculi by demonstrating that Milner s translations of lambda terms into untyped pi calculus both preserve and reAEect polymorphic typing. Process calculi with weaker ML style polymorphism have been developed by Gay [Gay93] and Vasconcelos and Honda [VH93]. A rather dioeerent style of polymorphism is considered by Liu and Walker [LW95] Many other type systems have been proposed for process calculi. One that particularly invites comparison with the present system is the pi calculus with input output modalities developed by the present authors ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....between the polymorphic pi and lambda calculi by demonstrating that Milner s translations of lambda terms into untyped pi calculus both preserve and reflect polymorphic typing. Process calculi with weaker ML style polymorphism have been developed by Gay [Gay93] and Vasconcelos and Honda [VH93]. A rather different style of system is considered by Liu and Walker [LW95] here, polymorphism arises not from type quantification, but by explicitly declaring the possible set of types of values that a given channel may carry. Typing itself does not guarantee absence of run time errors; for this ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic picalculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004. 50

....shall be used for recursive calls or recursive message passing if there is danger that the recursion does not terminate. 5 RELATED WORK The majority of work on types for concurrent languages is based on Milner s calculus [8] and similar calculi. The problem of inferring most general types [4, 19] and subtyp ing [3, 6, 13, 17, 18] was considered. But these type systems differ in an important aspect from process types: The underlying calculi do not keep the message order. Not much work was done on type systems able to deal with constraints on the ordering of messages. Nierstrasz [11] ....

V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings CONCUR '93, July 1993.

....type model. 5 Related Work Much work on types for concurrent languages and models has been done. The majority of this work is based on Milner s calculus [10, 12] and similar calculi. Especially, the problem of inferring most general types was considered by Gay [4] and Vasconcelos and Honda [22]. Nierstrasz [15] Pierce and Sangiorgi [16] Vasconcelos [21] and Kobayashi and Yonezawa [6] deal with subtyping in such calculi. But their type models differ in an important aspect from the one presented in this work: They are not able to represent constraints on the ordering of messages and, ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings CONCUR'93, July 1993.

....the channel plustwo would be given the type l[Num; l[Num] since it is used to communicate pairs where the first element is a number and the second is a channel that is used to send a single number. This type system can be extended in many ways, for instance by adding polymorphism [Gay93, VH93, Tur95, LW95b] Of more interest here, however, is the possibility of refining it so that the types of channels carry more information about how they are used. For example, we can straightforwardly capture the polarity (or directionality) of communications on channels like plustwo by introducing ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....axiomatize subtyping so that Theorem 1 and 2 are provable. Much work on types for concurrent languages and models has been done. The majority of this work is based on the calculus (Milner et al. 1992) especially the problem of inferring most general types was considered by Gay (1993) Vasconcelos and Honda (1993) and Vasconcelos (1994) Nierstrasz (1993) Pierce and Sangiorgi (1993) Vasconcelos (1994) and Kobayashi and Yonezawa (1994) deal with subtyping in such calculi. But their type models differs in an important aspect from the one presented in this paper: They are not able to represent constraints ....

Vasconcelos, V.T. and Honda, K. (1993) Principal typing schemes in a polyadic picalculus.

....of elements. 6 Related Work Much work on types for concurrent languages and models has been done. The majority of this work is based on Milner s calculus [15, 17] and similar calculi. Especially, the problem of inferring most general types was considered by Gay [5] and Vasconcelos and Honda [28]. Nierstrasz [19] Pierce and Sangiorgi [20] Vasconcelos [27] and Kobayashi and Yonezawa [10] deal with subtyping in such calculi. But their type models differ in an important aspect from the one presented in this work: They cannot represent constraints on the order of messages and ensure ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings CONCUR'93, July 1993.

....For example, the channel plustwo would be given the type l[Num; l[Num] since it is used to communicate pairs where the first element is a number and the second is a channel that is used to send a single number. This type system can be extended in many ways, for instance by adding polymorphism [Gay93, VH93, Tur95, LW95b]. Of more interest here, however, is the possibility of refining it so that the types of channels carry more information about how they are used. For example, we can straightforwardly capture the polarity (or directionality) of communications on channels like plustwo by introducing two new channel ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....more pragmatic requirement that well typedness must be automatically and efficiently verifiable. Milner s sort discipline plays an essential role in later papers on properties of the calculus [Wal92, San92] it has been further studied by Turner [Tur94] Gay [Gay93] and Vasconcelos and Honda [VH93], who consider the problem of inferring most general sortings. Our typing discipline retains the basic character of Milner s, while extending it in two dimensions. First, we replace by name matching of sorts with the more straightforward notion of structural matching, a technical modification that ....

....theoretical properties of our type system rather than to propose a pragmatic notation for programming, we adopt an explicitly typed presentation in which every bound name is annotated with a sorting. The algorithmic problem of inferring these annotations is deferred to future investigation (c.f. [Tur94, Gay93, VH93]) Our basic syntactic categories are defined by the grammar in Figure 1. We use the metavariables S, T , and U for sorts; P , Q, and R for process expressions; Gamma and Delta for sorting assumptions (or sortings) and a, b, c, etc. for channels (or names) For most of the paper, the only type ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....between the polymorphic pi and lambda calculi by demonstrating that Milner s translations of lambda terms into untyped pi calculus both preserve and reflect polymorphic typing. Process calculi with weaker ML style polymorphism have been developed by Gay [Gay93] and Vasconcelos and Honda [VH93]. A rather different style of polymorphism is considered by Liu and Walker [LW95] Many other type systems have been proposed for process calculi. One that particularly invites comparison with the present system is the pi calculus with input output modalities developed by the present authors ....

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic picalculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

....ensures that the program does not run into type constructor errors. 5.1 Type Scheme We first define type schemes for T , a typing system for L below. We let p; q; r; range over the type schemes. For simplicity we do not include recursive types, though its inclusion is straightforward, see [28]. Definition 5.1 (Type Scheme) p : ffl j ff j c j p Delta q j #p Delta q j Phi hl 1 : p 1 ; Delta Delta Delta ; l n : p n i j hl 1 : p 1 ; Delta Delta Delta ; l n : p n i In the above, ffl is the empty communication type. ff; fi; fl; denote type variables. c means constant ....

....and process variables, and, as a conclusion, type assignment for channels. While a single type is given to a term in the traditional functional types [4, 14, 15] many channel type pairs are given to a program in our typing for interaction, showing existence of multiple interaction points (cf. [9, 28]) Thus the main sequent for processes takes a form: Gamma; B P Delta where Gamma is a set of type assignments to names and variables, B is a set of type assignments to process variables, and Delta is a set of type assignments for channels 3 , each of which is explained below. As said, ....

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V. T. Vasconcelos and K. Honda. Principal Typing Schemes in a Polyadic Pi-Calculus. In CONCUR'93, LNCS 715, 1993.

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Vasconcelos, V. T. and K. Honda, Principal typing schemes in a polyadic picalculus, in: Proceedings of the 4th International Conference on Concurrency

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V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR 1993, vol. 715 of LNCS, pp. 524--538. Springer-Verlag, 1993.

No context found.

Vasco T. Vasconcelos and Kohei Honda. Principal typing schemes in a polyadic pi-calculus. In Proceedings of CONCUR '93, July 1993. Also available as Keio University Report CS-92-004.

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V. T. Vasconcelos and K. Honda. Principal typing schemes in a polyadic pi-calculus. In CONCUR

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