scholarly journals Interactive Teaching of Programming Language Theory with a Proof Assistant

2020 ◽  
pp. 19-33
Author(s):  
Péter Bereczky ◽  
István Donkó ◽  
Dániel Horpácsi ◽  
Ambrus Kaposi ◽  
Dávid János Németh
Keyword(s):  
Programming Languages ◽  
Programming Language ◽  
Learning Experience ◽  
Formal Semantics ◽  
Type Systems ◽  
Language Theory ◽  
Interactive Methods ◽  
Proof Assistant ◽  
Track Record ◽  
New Material

Teaching of programming language theory has a long track record at ELTE Faculty of Informatics. Traditionally, formal semantics and type systems of programming languages, similarly to other theory-oriented subjects, were taught with the pen and paper method. However, modern proof assistants call for replacing this old-fashioned way of teaching with novel and interactive methods that bring deeper understanding, provide better learning experience and build technical skills in applying formal methods. The authors have launched practice classes for two programming language theory subjects and carefully developed course material based on executable and verifiable definitions formalised in the Coq proof assistant. In this paper, we share our experiences regarding the design and implementation of the new material, we outline the pros and cons of using a proof assistant in the courses, and we describe how the presented method may be adapted to other courses.

scholarly journals Ownership and Immutability in Coq

2021 ◽  
Author(s):  
◽  
Julian Mackay
Keyword(s):  
Programming Languages ◽  
Management System ◽  
Type Systems ◽  
Formal Proof ◽  
Proof Assistant ◽  
Significant Issue ◽  
The Coq Proof Assistant ◽  
Coq Proof Assistant

<p>A significant issue in modern programming languages is unsafe aliasing. Modern type systems have attempted to address this in two prominent ways; immutability and ownership, and often a combination of the two [4][17]. The goal of this thesis is to formalise Immutability and Ownership using the Coq Proof Assistant, a formal proof management system [13]. We encode three type systems using Coq; Featherweight Immutable Java, Featherweight Generic Java and Featherweight Ownership Generic Java, and prove them sound. We describe the challenges presented in encoding immutability, ownership and type systems in general in Coq.</p>

scholarly journals Modules over relative monads for syntax and semantics

2014 ◽  
Vol 26 (1) ◽  
pp. 3-37 ◽  
Author(s):  
BENEDIKT AHRENS
Keyword(s):  
Programming Languages ◽  
Programming Language ◽  
Functional Programming ◽  
Algebraic Characterization ◽  
Proof Assistant ◽  
Initial Model ◽  
Functional Programming Languages ◽  
Reduction Relation ◽  
Initial Object

We give an algebraic characterization of the syntax and semantics of a class of untyped functional programming languages.To this end, we introduce a notion of 2-signature: such a signature specifies not only the terms of a language, but also reduction rules on those terms. To any 2-signature (S, A) we associate a category of ‘models’. We then prove that this category has an initial object, which integrates the terms freely generated by S, and which is equipped with reductions according to the rules given in A. We call this initial object the programming language generated by (S, A). Models of a 2-signature are built from relative monads and modules over such monads. Through the use of monads, the models – and in particular, the initial model – come equipped with a substitution operation that is compatible with reduction in a suitable sense.The initiality theorem is formalized in the proof assistant Coq, yielding a machinery which, when fed with a 2-signature, provides the associated programming language with reduction relation and certified substitution.

scholarly journals Propositions-as-types and shared state

2021 ◽  
Vol 5 (ICFP) ◽  
pp. 1-30
Author(s):  
Pedro Rocha ◽  
Luís Caires
Keyword(s):  
Programming Languages ◽  
Programming Language ◽  
Linear Logic ◽  
Natural Extension ◽  
Concurrent Programming ◽  
Type Systems ◽  
Liveness Properties ◽  
Mutable State ◽  
Shared State ◽  
Logical Rules

We develop a principled integration of shared mutable state into a proposition-as-types linear logic interpretation of a session-based concurrent programming language. While the foundation of type systems for the functional core of programming languages often builds on the proposition-as-types correspondence, automatically ensuring strong safety and liveness properties, imperative features have mostly been handled by extra-logical constructions. Our system crucially builds on the integration of nondeterminism and sharing, inspired by logical rules of differential linear logic, and ensures session fidelity, progress, confluence and normalisation, while being able to handle first-class shareable reference cells storing any persistent object. We also show how preservation and, perhaps surprisingly, progress, resiliently survive in a natural extension of our language with first-class locks. We illustrate the expressiveness of our language with examples highlighting detailed features, up to simple shareable concurrent ADTs.

scholarly journals Ownership and Immutability in Coq

2021 ◽  
Author(s):  
◽  
Julian Mackay
Keyword(s):  
Programming Languages ◽  
Management System ◽  
Type Systems ◽  
Formal Proof ◽  
Proof Assistant ◽  
Significant Issue ◽  
The Coq Proof Assistant ◽  
Coq Proof Assistant

<p>A significant issue in modern programming languages is unsafe aliasing. Modern type systems have attempted to address this in two prominent ways; immutability and ownership, and often a combination of the two [4][17]. The goal of this thesis is to formalise Immutability and Ownership using the Coq Proof Assistant, a formal proof management system [13]. We encode three type systems using Coq; Featherweight Immutable Java, Featherweight Generic Java and Featherweight Ownership Generic Java, and prove them sound. We describe the challenges presented in encoding immutability, ownership and type systems in general in Coq.</p>

scholarly journals On some innovations in teaching the formal semantics using software tools

2020 ◽  
Vol 11 (1) ◽  
pp. 2-11
Author(s):  
William Steingartner
Keyword(s):  
Programming Languages ◽  
Programming Language ◽  
Semantic Representation ◽  
Formal Semantics ◽  
Teaching Tool ◽  
Design Development ◽  
Software Module ◽  
Structured Input ◽  
Input Program ◽  
Definition Of

AbstractIn this work we discuss the motivation for innovations and need of a teaching tool for the visualization of the natural semantics method of imperative programming languages. We present the rôle of the teaching software, its design, development and use in the teaching process. Our software module is able to visualize the natural semantics evaluation of programs. It serves as a compiler with environment that can visually interpret simple programming language Jane statements and to depict them into a derivation tree that represents the semantic method of natural semantics. A formal definition of programming language Jane used in the teaching of formal semantics and production rules in natural semantics for that language are shown as well. We present, how the presented teaching tool can provide particular visual steps in the process of finding the meaning of well-structured input program and to depict complete natural-semantic representation of an input program.

scholarly journals Solving string constraints with Regex-dependent functions through transducers with priorities and variables

2022 ◽  
Vol 6 (POPL) ◽  
pp. 1-31
Author(s):  
Taolue Chen ◽  
Alejandro Flores-Lamas ◽  
Matthew Hague ◽  
Zhilei Han ◽  
Denghang Hu ◽  
...  
Keyword(s):  
Programming Languages ◽  
Formal Language ◽  
Formal Semantics ◽  
Symbolic Execution ◽  
Language Theory ◽  
Regular Expressions ◽  
Constraint Language ◽  
Straight Line ◽  
Finite State ◽  
Lazy Semantics

Regular expressions are a classical concept in formal language theory. Regular expressions in programming languages (RegEx) such as JavaScript, feature non-standard semantics of operators (e.g. greedy/lazy Kleene star), as well as additional features such as capturing groups and references. While symbolic execution of programs containing RegExes appeals to string solvers natively supporting important features of RegEx, such a string solver is hitherto missing. In this paper, we propose the first string theory and string solver that natively provides such support. The key idea of our string solver is to introduce a new automata model, called prioritized streaming string transducers (PSST), to formalize the semantics of RegEx-dependent string functions. PSSTs combine priorities, which have previously been introduced in prioritized finite-state automata to capture greedy/lazy semantics, with string variables as in streaming string transducers to model capturing groups. We validate the consistency of the formal semantics with the actual JavaScript semantics by extensive experiments. Furthermore, to solve the string constraints, we show that PSSTs enjoy nice closure and algorithmic properties, in particular, the regularity-preserving property (i.e., pre-images of regular constraints under PSSTs are regular), and introduce a sound sequent calculus that exploits these properties and performs propagation of regular constraints by means of taking post-images or pre-images. Although the satisfiability of the string constraint language is generally undecidable, we show that our approach is complete for the so-called straight-line fragment. We evaluate the performance of our string solver on over 195000 string constraints generated from an open-source RegEx library. The experimental results show the efficacy of our approach, drastically improving the existing methods (via symbolic execution) in both precision and efficiency.

PERANGKAT LUNAK KOMPUTER

2020 ◽  
Author(s):  
Cut Nabilah Damni
Keyword(s):  
Programming Languages ◽  
Programming Language ◽  
Operating Systems ◽  
Source Code ◽  
Computer Software ◽  
Computer Programs ◽  
Application Systems ◽  
Executable Programs

AbstrakSoftware komputer atau perangkat lunak komputer merupakan kumpulan instruksi (program atau prosedur) untuk dapat melaksanakan pekerjaan secara otomatis dengan cara mengolah atau memproses kumpulan intruksi (data) yang diberikan. (Yahfizham, 2019 : 19) Sebagian besar dari software komputer dibuat oleh (programmer) dengan menggunakan bahasa pemprograman. Orang yang membuat bahasa pemprograman menuliskan perintah dalam bahasa pemprograman seperti layaknya bahasa yang digunakan oleh orang pada umumnya dalam melakukan perbincangan. Perintah-perintah tersebut dinamakan (source code). Program komputer lainnya dinamakan (compiler) yang digunakan pada (source code) dan kemudian mengubah perintah tersebut kedalam bahasa yang dimengerti oleh komputer lalu hasilnya dinamakan program executable (EXE). Pada dasarnya, komputer selalu memiliki perangkat lunak komputer atau software yang terdiri dari sistem operasi, sistem aplikasi dan bahasa pemograman.AbstractComputer software or computer software is a collection of instructions (programs or procedures) to be able to carry out work automatically by processing or processing the collection of instructions (data) provided. (Yahfizham, 2019: 19) Most of the computer software is made by (programmers) using the programming language. People who make programming languages write commands in the programming language like the language used by people in general in conducting conversation. The commands are called (source code). Other computer programs called (compilers) are used in (source code) and then change the command into a language understood by the computer and the results are called executable programs (EXE). Basically, computers always have computer software or software consisting of operating systems, application systems and programming languages.

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