What is this?
A parser generator: you write a grammar for your language or file format, and ANTLR generates a parser that builds parse trees, plus listener/visitor interfaces to react to recognized phrases. Widely used to build languages, tools, and frameworks.
A parser generator: you write a grammar for your language or file format, and ANTLR generates a parser that builds parse trees, plus listener/visitor interfaces to react to recognized phrases. Widely used to build languages, tools, and frameworks.Is it a tool I run, or a library I call from my code?Both halves: the generator is a Java command-line tool you run on a grammar file, and it emits parser source code. That generated code works together with a runtime library for your target language, which your project links in.
Both halves: the generator is a Java command-line tool you run on a grammar file, and it emits parser source code. That generated code works together with a runtime library for your target language, which your project links in.How do I go from a grammar to a working parser?Write a .g4 grammar, run the ANTLR jar on it with Java, and it generates parser plus listener/visitor code in your chosen target language; then add the matching ANTLR runtime library to your project. The Getting started with v4 guide walks through a first example.
Write a .g4 grammar, run the ANTLR jar on it with Java, and it generates parser plus listener/visitor code in your chosen target language; then add the matching ANTLR runtime library to your project. The Getting started with v4 guide walks through a first example.Which languages can it generate parsers for?Ten targets: Java, C#, Python 3, JavaScript, TypeScript, Go, C++, Swift, Dart and PHP. You pick one target, generate, and link the matching ANTLR runtime library into your project.
Ten targets: Java, C#, Python 3, JavaScript, TypeScript, Go, C++, Swift, Dart and PHP. You pick one target, generate, and link the matching ANTLR runtime library into your project.Is upgrading to a newer ANTLR release always safe?Not blindly: ANTLR skips semver rules. Minor releases can include breaking changes, backward compatibility is guaranteed only for patch bumps, and the policy is to regenerate your parsers with every release.
Not blindly: ANTLR skips semver rules. Minor releases can include breaking changes, backward compatibility is guaranteed only for patch bumps, and the policy is to regenerate your parsers with every release.Where does it run?The generator runs anywhere Java runs - Windows, macOS, Linux - and the generated parsers run wherever your target language runs, from JVM servers to browsers (JavaScript, TypeScript) and phones (Swift, Dart).
The generator runs anywhere Java runs - Windows, macOS, Linux - and the generated parsers run wherever your target language runs, from JVM servers to browsers (JavaScript, TypeScript) and phones (Swift, Dart).Do parsers generated for different languages behave the same?Yes - keeping all 10 targets consistent is an explicit design goal the team calls unique and highly valuable. Every release is a complete release of the tool and all runtimes under one shared version number.
Yes - keeping all 10 targets consistent is an explicit design goal the team calls unique and highly valuable. Every release is a complete release of the tool and all runtimes under one shared version number.Does it still support Python 2?No. As of version 4.14 Python 2 support is dropped, since Python 2 was officially halted in 2020 and consistent quality across targets could no longer be maintained. Use the Python 3 target.
No. As of version 4.14 Python 2 support is dropped, since Python 2 was officially halted in 2020 and consistent quality across targets could no longer be maintained. Use the Python 3 target.Do I have to write every grammar from scratch?No - there is a companion collection of ready-made grammars without actions, where each root directory is the lowercase name of the language it parses, like java, cpp, csharp or c.
No - there is a companion collection of ready-made grammars without actions, where each root directory is the lowercase name of the language it parses, like java, cpp, csharp or c.What is the best way to learn it?The Definitive ANTLR 4 Reference, the book the README recommends: it demystifies parsing data formats like JSON, network protocols like SMTP, and server config files. The book's source code is also available online.
The Definitive ANTLR 4 Reference, the book the README recommends: it demystifies parsing data formats like JSON, network protocols like SMTP, and server config files. The book's source code is also available online.What are similar projects?flatbuffers, PHP-Parser, nom, quicktype, grammars-v4, TabNine, fq, hello-algo
flatbuffers, PHP-Parser, nom, quicktype, grammars-v4, TabNine, fq, hello-algo