Parser, pretty-printer and data structures library for working with the stella language in Swift.
Code generated by the ANTLR for Swift is terrible... So this package provides a more convenient interface to access Stella's syntax constructions as well as the parser built on top of the SwiftParsec library, which is a port of the original Haskell's Parsec library to Swfit.
Don't forget to install Swift if you don't have it.
Use swift --version to check installation.
To use this package inside another swift package,
add the following dependency to your Package.swift file:
dependencies: [
.package(url: "https://github.com/Artem-Goldenberg/SwiftStella.git", from: "1.2.1")
],Then you can include this package as a module in normal Swift files like this:
import StellaIf you want to clone this package and run tests for the parser, you need to clone
the repository with this submodule repository
containing example Stella programs, on which the parser is being tested.
To do it you can simply use:
git clone --recurse-submodules "https://github.com/Artem-Goldenberg/SwiftStella.git"
If you've already cloned without the
--recurse-submodules, usegit submodule initand thengit submodule updatecommands to download needed repository.
After that, you can build the package or run tests using
swift build
swift test
Also, if you want to quickly see the parse tree for some Stella source, you can run
swift run QuickParse <your stella source file>
It will print the serialized parse tree and pretty printed source program back to the standard output.
For development version there is also a
TestGeneratorexecutable target, which parses current test files and prints serizlized program trees to theprinted-treesfolder it also saves pretty printed sources from the ast toprinted-codeforlder, this is how you can generate and update test files. To run it, switch to the repository root directory and executeswift run TestGeneratorcommand.
Quicker to demonstrate by an example:
import Stella
func parse(sourceText: String) throws {
// get Parsec parsers for Stella's syntactic elements by using
// the static attribute `parser` on them, see library sources
// (or explore with `Stella.` completions) for all syntax elements
let stellaParser = Stella.Program.parser // or just use Program.parser
// you can use Parsec parser's `run` method to run the parser on the specified text
// and source file name (for error messages). See docs for Swift's Parsec library, if
// you want to learn more about how to work with these parsers
let program: Program = try stellaParser.run(
sourceName: "somefilename.stella",
input: sourceText
)
// use the `code` variable on any syntax element to get
// the reprinted source text of that element
let text = program.code
let declarations = program.declarations // get the list of all declarations
// now you can do whatever you want with them:
for decl in declarations {
switch decl {
case .function(_, name, params, returnType, _, body, returnExpr):
...
case .genericFunction(...):
...
...
}
}
}See Syntax.swift and Type.swift files for all cases and all syntax elements of the Stella language.