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parser

AST and parsers for the MoonBit programming language

parser
lexer
AST
MoonBit
moon add moonbitlang/parser@0.3.15
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Version
0.3.15
License
Apache-2.0
Repository
Last updated
2 days ago
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Dependencies

README

#moonbitlang/parser

Note: This module is highly experimental and unstable. Use with caution.

A parser implementation for the MoonBit programming language, written in MoonBit, providing lexical analysis and syntax parsing capabilities.

This module defines the Abstract Syntax Tree (AST) and provides parsers for MoonBit source code. It includes both a hand-written LL(k) parser with error recovery and an LR(1) parser generated by moonyacc.

#Project Structure

.
├── tokens/            # token definitions and utilities
├── lexer/             # Lexical analysis components
├── mbti_ast/          # AST for .mbti files
├── mbti_parser/       # LR parser for .mbti files
├── syntax/            # AST and utils for MoonBit source code
├── handrolled_parser/ # Hand-written parser implementation
├── yacc_parser/       # LR parser generated by moonyacc
├── test/              # Test suite
└── top.mbt            # parsing entries

#Usage

///|
test {
  let source =
    #| let number = 123
    #| fn add(a: Int, b: Int) -> Int {
    #|   a + b
    #| }
    #| enum Color {
    #|   Red
    #|   Green
    #|   Blue
    #| }
    #| struct Point {
    #|   x: Int
    #|   y: Int
    #| }
  let (impls, _) = parse_string(source)
  @json.inspect(impls, content=[
    {
      "type": "Impl::TopLetDef",
      "binder": { "type": "Binder", "name": "number", "loc": null },
      "ty": null,
      "expr": {
        "type": "Expr::Constant",
        "c": { "type": "Constant::Int", "0": "123" },
        "loc": null,
      },
      "vis": { "type": "Visibility::Default" },
      "is_constant": false,
      "loc": null,
      "attrs": [],
      "doc": "",
    },
    {
      "type": "Impl::TopFuncDef",
      "fun_decl": {
        "type": "FunDecl",
        "type_name": null,
        "name": { "type": "Binder", "name": "add", "loc": null },
        "has_error": null,
        "is_async": null,
        "decl_params": [
          {
            "type": "Parameter::Positional",
            "binder": { "type": "Binder", "name": "a", "loc": null },
            "ty": {
              "type": "Type::Name",
              "constr_id": {
                "type": "ConstrId",
                "id": { "type": "LongIdent::Ident", "0": "Int" },
                "loc": null,
              },
              "tys": [],
              "loc": null,
            },
          },
          {
            "type": "Parameter::Positional",
            "binder": { "type": "Binder", "name": "b", "loc": null },
            "ty": {
              "type": "Type::Name",
              "constr_id": {
                "type": "ConstrId",
                "id": { "type": "LongIdent::Ident", "0": "Int" },
                "loc": null,
              },
              "tys": [],
              "loc": null,
            },
          },
        ],
        "params_loc": null,
        "quantifiers": [],
        "return_type": {
          "type": "Type::Name",
          "constr_id": {
            "type": "ConstrId",
            "id": { "type": "LongIdent::Ident", "0": "Int" },
            "loc": null,
          },
          "tys": [],
          "loc": null,
        },
        "error_type": { "type": "ErrorType::NoErrorType" },
        "vis": { "type": "Visibility::Default" },
        "attrs": [],
        "doc": "",
      },
      "decl_body": {
        "type": "DeclBody::DeclBody",
        "local_types": [],
        "expr": {
          "type": "Expr::Infix",
          "op": {
            "type": "Var",
            "name": { "type": "LongIdent::Ident", "0": "+" },
            "loc": null,
          },
          "lhs": {
            "type": "Expr::Ident",
            "id": {
              "type": "Var",
              "name": { "type": "LongIdent::Ident", "0": "a" },
              "loc": null,
            },
            "loc": null,
          },
          "rhs": {
            "type": "Expr::Ident",
            "id": {
              "type": "Var",
              "name": { "type": "LongIdent::Ident", "0": "b" },
              "loc": null,
            },
            "loc": null,
          },
          "loc": null,
        },
      },
      "loc": null,
    },
    {
      "type": "Impl::TopTypeDef",
      "0": {
        "type": "TypeDecl",
        "tycon": "Color",
        "tycon_loc": null,
        "params": [],
        "components": {
          "type": "TypeDesc::Variant",
          "0": [
            {
              "type": "ConstrDecl",
              "name": { "type": "ConstrName", "name": "Red", "loc": null },
              "args": null,
              "tag": null,
              "attrs": [],
              "loc": null,
              "doc": "",
            },
            {
              "type": "ConstrDecl",
              "name": { "type": "ConstrName", "name": "Green", "loc": null },
              "args": null,
              "tag": null,
              "attrs": [],
              "loc": null,
              "doc": "",
            },
            {
              "type": "ConstrDecl",
              "name": { "type": "ConstrName", "name": "Blue", "loc": null },
              "args": null,
              "tag": null,
              "attrs": [],
              "loc": null,
              "doc": "",
            },
          ],
        },
        "attrs": [],
        "doc": "",
        "type_vis": { "type": "Visibility::Default" },
        "deriving": [],
        "loc": null,
      },
    },
    {
      "type": "Impl::TopTypeDef",
      "0": {
        "type": "TypeDecl",
        "tycon": "Point",
        "tycon_loc": null,
        "params": [],
        "components": {
          "type": "TypeDesc::Record",
          "0": [
            {
              "type": "FieldDecl",
              "name": { "type": "FieldName", "label": "x", "loc": null },
              "ty": {
                "type": "Type::Name",
                "constr_id": {
                  "type": "ConstrId",
                  "id": { "type": "LongIdent::Ident", "0": "Int" },
                  "loc": null,
                },
                "tys": [],
                "loc": null,
              },
              "mut": false,
              "vis": { "type": "Visibility::Default" },
              "loc": null,
              "attrs": [],
              "doc": "",
            },
            {
              "type": "FieldDecl",
              "name": { "type": "FieldName", "label": "y", "loc": null },
              "ty": {
                "type": "Type::Name",
                "constr_id": {
                  "type": "ConstrId",
                  "id": { "type": "LongIdent::Ident", "0": "Int" },
                  "loc": null,
                },
                "tys": [],
                "loc": null,
              },
              "mut": false,
              "vis": { "type": "Visibility::Default" },
              "loc": null,
              "attrs": [],
              "doc": "",
            },
          ],
        },
        "attrs": [],
        "doc": "",
        "type_vis": { "type": "Visibility::Default" },
        "deriving": [],
        "loc": null,
      },
    },
  ])
}

You can also explore the parsing results using the AST Explorer.

#Build & Test

This project uses the MoonBit build system:

moon update
moon check
moon test

#Contributing

We welcome contributions to this project! Please see CONTRIBUTING.md for guidelines on how to contribute and report bugs.

#
Parser

source
pub(all) enum Parser {
  MoonYacc
  Handrolled
}

#
parse_file

source

#
parse_string

source

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