DOCSLIB.ORG

A Framework for Implementing Pluggable Type Systems

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Framework for Implementing Pluggable Type Systems A Framework for Implementing Pluggable Type Systems Chris Andreae and James Noble Shane Markstrum and Todd Millstein Victoria University of Wellington University of California, Los Angeles {chris,kjx}@mcs.vuw.ac.nz {smarkstr,todd}@cs.ucla.edu Abstract Aside from its clear benefits to programmers, a framework for plug- Pluggable types have been proposed to support multiple type gable type systems is also beneficial to programming language re- systems in the same programming language. We have designed searchers, who can use such a framework to experiment easily with novel type systems. and implemented JAVACOP, a program constraint system for im- In this paper, we present the design, implementation, and eval- plementing practical pluggable type systems for Java. JAVACOP enforces user-defined typing constraints written in a declarative uation of a practical framework for implementing pluggable type and expressive rule language. We have validated our design by systems in Java [3, 32], which we call JAVACOP (“Constraints (re)implementing a range of type systems and program checkers. On Programs”). We have designed a declarative rule language in By using a program constraint system to implement pluggable which programmers may specify their pluggable type systems. types, programmers are able to check that their programs will oper- User-defined rules work over a rich abstract syntax tree (AST) rep- ate correctly in restricted environments, adhere to strict program- resentation for Java 1.5 programs and can refer to user-defined type ming rules, avoid null pointer errors or scoped memory excep- information, which is expressed as annotations in Java 1.5’s meta- tions, and meet style guidelines, while programming language re- data facility [6]. JAVACOP then automatically enforces these rules searchers can easily experiment with novel type systems. on programs as they are compiled. As a simple example, consider the following code which uses a Categories and Subject Descriptors D.1.5 [Programming Tech- @NonNull annotation to specify the additional type constraint that niques]: Object-oriented Programming; D.2.1 [Software Engi- the field firstname (of Java type String) may never be null. neering]: Requirements/Specifications—Tools class Person { General Terms Design, Languages, Reliability @NonNull String firstname = "Chris"; void setFirstName(String newname) Keywords JavaCOP, pluggable type systems { firstname = newname; } } 1. Introduction Clearly, the assignment to firstname within setFirstName is Many researchers have noticed that traditional type systems do not potentially erroneous, since newname may be null. It is straight- enforce all of the kinds of constraints that may be useful for pro- forward for a user to write a JAVACOP rule that would discover grammers. A common way to address these limitations is to define this potential error. For example, the JAVACOP rule below requires an extension to a base type system that introduces new constraints the right-hand-side expression of each assignment statement to be on programs, often in conjunction with new program annotations. demonstrably nonnull whenever the type of the left-hand-side vari- nonnull For example, a annotation can be used to require a vari- able or field is declared as such. able to never point to null [26], a confined annotation can be used to ensure that no references to instances of a class can escape the rule checkNonNull(Assign a){ class’s package [49], and various kinds of readonly annotations where(requiresNonNull(a.lhs)){ can be used to ensure that an object reference is not modified [7]. require(definitelyNotNull(a.rhs)): Unfortunately, language designers cannot anticipate all of the error(a,"Possible null assignment" constraints and conventions that programmers will want to spec- + " to @NonNull"); } } ify, nor can they anticipate all of the practical ways in which such properties can be checked. Further, different rules may be impor- This rule relies on two user-defined helper predicates. tant to enforce in different programs, and it would be too unwieldy The requiresNonNull predicate checks that the given vari- to require all programs to obey all rules all of the time. Therefore able or field was declared with the @NonNull attribute. it is desirable to provide a framework for user-defined type sys- The definitelyNotNull predicate inspects the given expres- tems. Bracha has previously identified the need for such a frame- sion to determine if it is definitely nonnull. For example, work, coining the term pluggable types for the resulting system [8]. definitelyNotNull would define literals other than null to be nonnull. Assuming definitelyNotNull does not allow an arbitrary variable to be considered nonnull, the assignment to firstname in setFirstName will fail our rule, causing the com- piler to output the following error message: Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation Person.java:4: Possible null assignment to on the first page. To copy otherwise, to republish, to post on servers or to redistribute @NonNull to lists, requires prior specific permission and/or a fee. { firstname = newname; } OOPSLA’06 October 22–26, 2006, Portland, Oregon, USA. ˆ Copyright c 2006 ACM 1-59593-348-4/06/0010. $5.00. 1 error As detailed in Section 5, there have been several prior systems COP integrates naturally with existing Java compiler frame- that allow user-defined constraints to be enforced on programs. works. JAVACOP is distinguished by a novel combination of features that Checking each compilation unit individually does have some is targeted to support the development of practical pluggable type liabilities. For example, an apparently simple rule such as “My- systems: Package must contain exactly one class” cannot be checked with JAVACOP, because JAVACOP will never see the entire package, only the individual classes of which it is comprised. • JAVACOP leverages Java 1.5’s metadata facility to allow users Given JAVACOP’s place in the development life-cycle and the to introduce additional type specifications. Java’s annotations kind of syntax-directed local rules JAVACOP is designed to cannot be placed directly on types, but only on declarations. check, we consider modularity a valid design tradeoff. Further, As such, JAVACOP supports two main kinds of annotations for in some cases rules can be reformulated so that JAVACOP can pluggable types. First, an annotation on a class declaration can check them modularly (e.g., JAVACOP can enforce the rule be used to indicate that all values of the Java type correspond- “classes in MyPackage must be named MyClass”, and Java’s ing to that class satisfy some additional properties. For exam- naming rules will ensure that MyClass is unique). ple, the declaration of a class C can be annotated as @Confined to indicate that no instance of that class will escape the class’s We have implemented the JAVACOP framework as two log- package. Second, an annotation on a variable (local or formal) ically independent components. First, we have extended Sun’s or field declaration can be used to indicate that a particular vari- javac compiler, which is written in Java, with a Java API that able or field satisfies some additional properties. For example, provides a clean interface to the compiler’s internal AST and type in our Person class above, the firstname field is declared to structures. Just before code generation, a new pass in the compiler be both a String and to be never null. executes Java code that employs this API in order to enforce con- straints on the program being compiled. Second, we have imple- • JAVACOP employs a declarative, rule-based language for ex- mented a component that translates constraints in the JAVACOP pressing the semantics of these new annotations. While it would rule language to Java code employing our new API. This separa- be possible to write the rules directly in Java with respect to tion of concerns allows the JAVACOP rule language to easily evolve an AST API, we believe rules in JAVACOP’s language will be without requiring modifications to the javac compiler, and it ad- significantly easier for rule designers and programmers to un- mits the possibility of easily incorporating multiple languages for derstand and define correctly. Further, our rule-based language enforcing constraints on programs. has a natural correspondence with the traditional way in which We have validated the JAVACOP framework in several ways. syntax-directed type rules are specified. First, we illustrate the framework’s expressiveness and practical- • JAVACOP makes it possible for user-defined types specified ity by replicating a number of interesting type systems from the using annotations to interact with Java’s existing type system. literature, including confined types, scoped types, types for race This is a natural expectation for user-defined type systems; for detection, nonnull types, types for immutability, and generic own- example, consider the @NonNull annotation. A user may want ership types [49, 51, 27, 5, 47, 44]. We have also implemented to ensure that this annotation is only employed on declarations several style and convention checkers, including an EJB3.0 ver- of variables or fields of reference type, rather than of primitive ifier [21], as well as various code pattern detectors [18, 31] and type. To achieve this, the AST abstraction over which JAVACOP metrics tools [13]. Finally, we have tested the performance of the rules work includes full Java type information about program JAVACOP framework. In the worst case, the addition of JAVACOP entities, including information about type parameterization aris- rule checking increases total compile time by a factor of two. ing from Java 1.5’s generics. The AST abstraction also includes The rest of this paper is structured as follows.
Load more

Recommended publications
  • UNIX and Computer Science Spreading UNIX Around the World: by Ronda Hauben an Interview with John Lions
    Winter/Spring 1994 Celebrating 25 Years of UNIX Volume 6 No 1 "I believe all significant software movements start at the grassroots level. UNIX, after all, was not developed by the President of AT&T." Kouichi Kishida, UNIX Review, Feb., 1987 UNIX and Computer Science Spreading UNIX Around the World: by Ronda Hauben An Interview with John Lions [Editor's Note: This year, 1994, is the 25th anniversary of the [Editor's Note: Looking through some magazines in a local invention of UNIX in 1969 at Bell Labs. The following is university library, I came upon back issues of UNIX Review from a "Work In Progress" introduced at the USENIX from the mid 1980's. In these issues were articles by or inter- Summer 1993 Conference in Cincinnati, Ohio. This article is views with several of the pioneers who developed UNIX. As intended as a contribution to a discussion about the sig- part of my research for a paper about the history and devel- nificance of the UNIX breakthrough and the lessons to be opment of the early days of UNIX, I felt it would be helpful learned from it for making the next step forward.] to be able to ask some of these pioneers additional questions The Multics collaboration (1964-1968) had been created to based on the events and developments described in the UNIX "show that general-purpose, multiuser, timesharing systems Review Interviews. were viable." Based on the results of research gained at MIT Following is an interview conducted via E-mail with John using the MIT Compatible Time-Sharing System (CTSS), Lions, who wrote A Commentary on the UNIX Operating AT&T and GE agreed to work with MIT to build a "new System describing Version 6 UNIX to accompany the "UNIX hardware, a new operating system, a new file system, and a Operating System Source Code Level 6" for the students in new user interface." Though the project proceeded slowly his operating systems class at the University of New South and it took years to develop Multics, Doug Comer, a Profes- Wales in Australia.
    [Show full text]
  • To Type Or Not to Type: Quantifying Detectable Bugs in Javascript
    To Type or Not to Type: Quantifying Detectable Bugs in JavaScript Zheng Gao Christian Bird Earl T. Barr University College London Microsoft Research University College London London, UK Redmond, USA London, UK [email protected] [email protected] [email protected] Abstract—JavaScript is growing explosively and is now used in to invest in static type systems for JavaScript: first Google large mature projects even outside the web domain. JavaScript is released Closure1, then Microsoft published TypeScript2, and also a dynamically typed language for which static type systems, most recently Facebook announced Flow3. What impact do notably Facebook’s Flow and Microsoft’s TypeScript, have been written. What benefits do these static type systems provide? these static type systems have on code quality? More concretely, Leveraging JavaScript project histories, we select a fixed bug how many bugs could they have reported to developers? and check out the code just prior to the fix. We manually add The fact that long-running JavaScript projects have extensive type annotations to the buggy code and test whether Flow and version histories, coupled with the existence of static type TypeScript report an error on the buggy code, thereby possibly systems that support gradual typing and can be applied to prompting a developer to fix the bug before its public release. We then report the proportion of bugs on which these type systems JavaScript programs with few modifications, enables us to reported an error. under-approximately quantify the beneficial impact of static Evaluating static type systems against public bugs, which type systems on code quality.
    [Show full text]
  • Safejava: a Unified Type System for Safe Programming
    SafeJava: A Unified Type System for Safe Programming by Chandrasekhar Boyapati B.Tech. Indian Institute of Technology, Madras (1996) S.M. Massachusetts Institute of Technology (1998) Submitted to the Department of Electrical Engineering and Computer Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 2004 °c Massachusetts Institute of Technology 2004. All rights reserved. Author............................................................................ Chandrasekhar Boyapati Department of Electrical Engineering and Computer Science February 2, 2004 Certified by........................................................................ Martin C. Rinard Associate Professor, Electrical Engineering and Computer Science Thesis Supervisor Accepted by....................................................................... Arthur C. Smith Chairman, Department Committee on Graduate Students SafeJava: A Unified Type System for Safe Programming by Chandrasekhar Boyapati Submitted to the Department of Electrical Engineering and Computer Science on February 2, 2004, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract Making software reliable is one of the most important technological challenges facing our society today. This thesis presents a new type system that addresses this problem by statically preventing several important classes of programming errors. If a program type checks, we guarantee at compile time that the program
    [Show full text]
  • Lint, a C Program Checker Lint, a C
    Lint, a C Program Checker Fr ans Kunst Vrije Universiteit Amsterdam Afstudeer verslag 18 mei 1988 Lint, a C Program Checker Fr ans Kunst Vrije Universiteit Amsterdam This document describes an implementation of a program which does an extensive consistencyand plausibility check on a set of C program files. This may lead to warnings which help the programmer to debug the program, to remove useless code and to improve his style. The program has been used to test itself and has found bugs in sources of some heavily used code. -2- Contents 1. Introduction 2. Outline of the program 3. What lint checks 3.1 Set, used and unused variables 3.2 Flowofcontrol 3.3 Functions 3.4 Undefined evaluation order 3.5 Pointer alignment problems 3.6 Libraries 4. Howlint checks 4.1 The first pass data structure 4.2 The first pass checking mechanism 4.3 The second pass data structure 4.4 The second pass checking mechanism 5. Howtomakelint shut up 6. User options 7. Ideas for further development 8. Testing the program 9. References Appendix A − The warnings Appendix B − The Ten Commandments for C programmers -3- 1. Introduction C[1][2] is a dangerous programming language. The programmer is allowed to do almost anything, as long as the syntax of the program is correct. This has a reason. In this way it is possible to makeafast compiler which produces fast code. The compiler will be fast because it doesn’tdomuch checking at com- pile time. The code is fast because the compiler doesn’tgenerate run time checks.
    [Show full text]
  • The TRUTH About How Codesonar Compares to PC-Lint
    The TRUTH About How CodeSonar Compares to PC-lint Gimpel Software Version 1, May 2016 As the recognized leader and standard bearer in the static analysis industry, we are flattered to be considered as a benchmark in many product comparisons. While we rarely find it necessary to respond to them, the Grammatech “white paper” comparing the CodeSonar product to PC-lint has the odious distinction of being an exception. Instead of focusing on the perceived merits of the Grammatech product, the white paper in question resorts to false claims and misrepresentations about PC-lint, perhaps as a result of marketplace pressure, which we feel should be balanced with a healthy dose of reality. About PC-lint PC-lint is a powerful and reputable C and C++ static analysis tool created by Gimpel Software in 1985 and continually improved during the past 30 years. During this time PC-lint has been an innovative leader in the industry by incorporating pioneering features such as inter-function and inter-module Value Tracking, Strong Type Checking and Dimensional Analysis, and User-Defined Function Semantics. PC-lint is trusted by many tens of thousands of developers, QA analysts, software testers, and forensic analysts and supports dozens of compilers and platforms, sports dozens of secondary features, and is deployed worldwide in virtually every industry including safety critical fields such as medical and automotive. About Grammatech’s white paper The white paper entitled “How CodeSonar Compares To PC-lint (And Similar Tools)”, avail- able from Grammatech’s website, purports to provide a comparison between the CodeSonar product and PC-lint (other tools are discussed but the focus is on PC-lint) but in reality is nothing more than a series of self-serving, misleading statements having little or no factual basis.
    [Show full text]
  • Cleanscape Fortran-Lint GUI User's Guide
    Cleanscape Fortran-lint GUI User’s Guide Version 6.3 Sales and Service Office 5850 Eubank Blvd. NE, B49-180 Albuquerque, NM 87111 Toll-free 800-94-4LINT 505-246-0267 Fax 505-247-2678 www.cleanscape.net [email protected] [email protected] Flint GUI User’s Guide PART I Introduction.................................................................................................................3 1.1 WELCOME..........................................................................................................................3 1.2 DOCUMENTATION.............................................................................................................3 1.3 PURPOSE...........................................................................................................................3 A. Function............................................................................................................................3 B. Application.........................................................................................................................3 C. Advantages.......................................................................................................................4 D. Flow of Analysis................................................................................................................4 PART II Requirements, Installation, and Uninstallation.............................................................5 2.1 WINDOWS..........................................................................................................................5
    [Show full text]
  • Fortran Programmer's Guide
    Fortran Programmer’s Guide Fortran 77 4.2 Fortran 90 1.2 SunSoft, Inc. A Sun Microsystems, Inc. Business 2550 Garcia Avenue Mountain View, CA 94043 USA 415 960-1300 fax 415 969-9131 Part No.: 802-5664-10 Revision A, December 1996 Copyright 1996 Sun Microsystems, Inc., 2550 Garcia Avenue, Mountain View, California 94043-1100 U.S.A. All rights reserved. This product or document is protected by copyright and distributed under licenses restricting its use, copying, distribution, and decompilation. No part of this product or document may be reproduced in any form by any means without prior written authorization of Sun and its licensors, if any. Portions of this product may be derived from the UNIX® system, licensed from Novell, Inc., and from the Berkeley 4.3 BSD system, licensed from the University of California. UNIX is a registered trademark in the United States and other countries and is exclusively licensed by X/Open Company Ltd. Third-party software, including font technology in this product, is protected by copyright and licensed from Sun’s suppliers. RESTRICTED RIGHTS: Use, duplication, or disclosure by the U.S. Government is subject to restrictions of FAR 52.227- 14(g)(2)(6/87) and FAR 52.227-19(6/87), or DFAR 252.227-7015(b)(6/95) and DFAR 227.7202-3(a). Sun, Sun Microsystems, the Sun logo, Solaris, SunSoft, Sun WorkShop, Sun Performance WorkShop and Sun Performance Library are trademarks or registered trademarks of Sun Microsystems, Inc. in the United States and other countries. All SPARC trademarks are used under license and are trademarks or registered trademarks of SPARC International, Inc.
    [Show full text]
  • NBS FORTRAN Test Programs 3^1 No "I Volume 1- Documentation for Versions 1 and 3 V.I
    j I i Vt NBS SPECIAL PUBLICATION 399 J Volume 1 U.S. DEPARTMENT OF COMMERCE / National Bureau of Standards] National Bureau of Standards Library, £-01 Admin. BIdg. ncT 1 1981 13102^1 NBS FORTRAN Test Prog Volume 1-Documentation for Versions 1 and 3 NATIONAL BUREAU OF STANDARDS The National Bureau of Standards^ was established by an act of Congress March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology and facilitate their effective application for public benefit. To this end, the Bureau conducts research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau consists of the Institute for Basic Standards, the Institute for Materials Research, the Institute for Applied Technology, the Institute for Computer Sciences and Technology, and the Office for Information Programs. THE INSTITUTE FOR BASIC STANDARI>S provides the central basis within the United States of a complete and consistent system of physical measurement; coordinates that system with measurement systems of other nations; and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. The Institute consists of a Center for Radiation Research, an Office of Meas- urement Services and the following divisions: Applied Mathematics — Electricity — Mechanics
    [Show full text]
  • Part II: Julia for Data Science
    Julia Part II Julia for Data Science Prof. Matthew Roughan [email protected] http://www.maths.adelaide.edu.au/matthew.roughan/ UoA Oct 31, 2017 M.Roughan (UoA) Julia Part II Oct 31, 2017 1 / 41 A basic problem about any body of data is to make it more easily and effectively handleable by minds – our minds, her mind, his mind. John W. Tukey, Exploratory Data Analysis, Addison-Wesley, 1977 M.Roughan (UoA) Julia Part II Oct 31, 2017 2 / 41 Section 1 Get Started M.Roughan (UoA) Julia Part II Oct 31, 2017 3 / 41 Interface Cuteness Matlab uses help, Julia switches into help mode by typeing ? I lookfor in Matlab becomes apropos, e.g., apropos("determinant") In Julia can access OS commands by typing ;, e.g., ;pwd Useful things to know I history with up and down keys I matches partial strings I auto-complete with TAB Standard shell-commands I Ctrl-c interrupt process I Ctrl-a start of the line I Ctrl-e end of the line I Ctrl-d exit Startup file ˜/.juliarc.jl M.Roughan (UoA) Julia Part II Oct 31, 2017 4 / 41 Other useful bits and pieces Comments in shell-style # Functions that modify their arguments have a name like sort! Useful commands whos() @which sin(2) versioninfo() Numerical constants pi golden e im eulergamma Long numbers: 1_000_000 Others useful constants JULIA_HOME # path to julia executable nothing # function that returns void M.Roughan (UoA) Julia Part II Oct 31, 2017 5 / 41 Section 2 Plotting M.Roughan (UoA) Julia Part II Oct 31, 2017 6 / 41 Plot packages There are several plotting packages PyPlot: emulates Matlab, through Python’s matplotlib Gadfly: emulates R’s ggplot Plots: aims to become front end for all backends GR, UnicodePlots, Plotly, PlotlyJS, Vega, Winston, StatsPlots, PlotRecipes, GLVisualize, PGFPlots, Qwt, ..
    [Show full text]
  • Yacc: Yet Another Compiler-Compiler
    Yacc: Yet Another Compiler-Compiler http://dinosaur.compilertools.net/yacc/index.html The Lex & Yacc Page Yacc: Yet Another Compiler-Compiler Stephen C. Johnson AT&T Bell Laboratories Murray Hill, New Jersey 07974 ABSTRACT Computer program input generally has some structure; in fact, every computer program that does input can be thought of as defining an ``input language'' which it accepts. An input language may be as complex as a programming language, or as simple as a sequence of numbers. Unfortunately, usual input facilities are limited, difficult to use, and often are lax about checking their inputs for validity. Yacc provides a general tool for describing the input to a computer program. The Yacc user specifies the structures of his input, together with code to be invoked as each such structure is recognized. Yacc turns such a specification into a subroutine that handles the input process; frequently, it is convenient and appropriate to have most of the flow of control in the user's application handled by this subroutine. The input subroutine produced by Yacc calls a user-supplied routine to return the next basic input item. Thus, the user can specify his input in terms of individual input characters, or in terms of higher level constructs such as names and numbers. The user-supplied routine may also handle idiomatic features such as comment and continuation conventions, which typically defy easy grammatical specification. Yacc is written in portable C. The class of specifications accepted is a very general one: LALR(1) grammars with disambiguating rules. In addition to compilers for C, APL, Pascal, RATFOR, etc., Yacc has also been used for less conventional languages, including a phototypesetter language, several desk calculator languages, a document retrieval system, and a Fortran debugging system.
    [Show full text]
  • FORTRAN-Lint® Debugging Begins
    FORTRAN-lint ® a pre-compile analysis tool (includes a graphical source browser) Catch coding Efficient The problems early… development comprehensive save time, and analysis of money, and maintenance of FORTRAN-lint frustration FORTRAN 77 finds many bugs before and 90 programs before debugging even begins with traditional begins! FORTRAN-lint® debugging begins. The earlier a bug is caught, the less it costs to fix! FORTRAN-lint by is a tool designed to analyze FORTRAN source programs at all stages of their development. FORTRAN-lint begins by analyzing each source module separately just as a compiler would, only much more thoroughly. Then FORTRAN-lint goes on to do what no compiler can do: FORTRAN-lint looks at all the modules of the project and detects errors between modules. FORTRAN-lint detects: ◆ Inconsistencies in variable and argument lists between modules ◆ Inconsistencies in common block declarations ◆ Questionable, non-portable or wasteful code ◆ Unused variables and functions ◆ Variables which are referenced but never assigned a value ◆ Obsolete FORTRAN 77 features in FORTRAN 90 code ◆ Variable usage conflicts FORTRAN-lint provides support for Native FORTRAN 77 and FORTRAN 90. The amount of diagnostic information produced by FORTRAN-lint is determined by options specified on the command line, and can vary from severe errors only to matters of style. FORTRAN-lint provides an extremely quick, convenient and reliable method for locating errors in programs. FORTRAN-lint saves time, money, and frustration! PUTTING FORTRAN-lint TO WORK SPEED DEBUGGING lint Debugging Sample CALL GETUNIT(5,PUNIT,|UNIT) FORTRAN-lint finds bugs and possible bugs before the ^ programmer even starts the debugging process.
    [Show full text]
  • Pylint Documentation Release 2.7.3
    Pylint Documentation Release 2.7.3 Logilab, PyCQA and contributors Mar 29, 2021 Contents 1 Introduction 3 1.1 What is Pylint?..............................................3 1.2 What Pylint is not?............................................3 2 Tutorial 5 2.1 Intro...................................................5 2.2 Getting Started..............................................5 2.3 Your First Pylint’ing...........................................6 2.4 The Next Step..............................................8 3 User Guide 11 3.1 Installation................................................ 11 3.2 Running Pylint.............................................. 11 3.3 Pylint output............................................... 14 3.4 Messages control............................................. 16 3.5 Configuration............................................... 19 3.6 Editor and IDE integration........................................ 21 4 How To Guides 27 4.1 How to Write a Checker......................................... 27 4.2 How To Write a Pylint Plugin...................................... 31 4.3 Transform plugins............................................ 32 5 Technical Reference 35 5.1 Startup and the Linter Class....................................... 35 5.2 Checkers................................................. 35 5.3 Optional Pylint checkers in the extensions module........................... 35 5.4 Pylint features.............................................. 43 5.5 Pylint and C extensions........................................
    [Show full text]