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    gleam-parser

    Parser and parsing utilities for the Gleam programming language in MoonBit

    gleam
    parser
    scanner
    ast
    morphir
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    Version
    0.1.0
    License
    Apache-2.0
    Repository
    Last updated
    16 hours ago
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    Dependencies

    #moonrockz/gleam-parser

    Parser and parsing utilities for the Gleam programming language in MoonBit. One expected user is morphir-moonbit, as a frontend that reads Gleam and a backend that writes it.

    Status: scanner, AST, parser, CST and diagnostics are done. The AST mirrors the Gleam compiler's untyped AST at v1.19.2; the parity oracle is the compiler itself.

    Done:

    • Scanner (tokenize): lossless tokens with trivia (whitespace, line breaks, //, /// and //// comments) that rebuild the source byte for byte; spans are UTF-8 byte offsets as in the compiler; a lexical error is a GL-SCAN-001 diagnostic with the compiler's message plus an Error token, and scanning goes on.
    • AST and JSON: the compiler's untyped AST (v1.19.2) with a canonical JSON encoder and decoder (docs/ast-json.md); a Rust oracle on gleam-core writes the same JSON, and tests/fixtures/ast prove byte equality.

    • Parser (parse_text, parse_module): a recursive-descent port of the compiler's parse.rs; on every fixture the canonical JSON equals the compiler's byte for byte, and the first error has the compiler's kind and span. A definition that does not parse is reported and skipped; the rest of the file is parsed.
    • CST (ParseResult.cst): every token grouped per definition; ModuleCst::to_source() is the text byte for byte, also with errors.
    • Dialect (Dialect::gleam_1_19()): what the parser accepts.
    • Report (render_plain, render_terminal, encode_diagnostics): the compiler's diagnostic layout, with colours, or as JSON.
    • Parity: on a pinned corpus of 25 published packages (233 files), all 233 files give the compiler's AST byte for byte (mise run test:parity); 44 rejection fixtures check the accept and reject verdicts and the first error against the compiler (mise run test:rejection).

    test {
      let r = @gleam.parse_text("import gleam/io\n\npub fn main() {\n  io.println(\"hi\")\n}\n")
      inspect(r.module_.definitions.length(), content="2")
      inspect(r.has_errors(), content="false")
    }

    Planned, in order:

    • Syntax tree: a read-only node model with six traversal styles.
    • Printer and formatter: Gleam source from an AST, gleam format parity.

    #Installation

    moon add moonrockz/gleam-parser

    In your package's moon.pkg:

    import {
  "moonrockz/gleam-parser" @gleam,
}

    #Development

    • mise run check: info, lint, format and all tests.
    • mise run test:targets: the library on wasm, wasm-gc, js and native.
    • mise run test:parity and mise run test:rejection: parity with the Gleam compiler on the corpus and on the rejection fixtures (see AGENTS.md).
    • See AGENTS.md for conventions and docs/cookbook/ for tested examples.

    Arg

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ArgNames

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Assert

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    AssignName

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Assignment

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    AssignmentKind

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    BinOp

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    BitArrayOption

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    BitArraySegment

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    BitArraySize

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    CallArg

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Clause

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ClauseGuard

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Comment

    source

    The scanner: tokens, trivia and lexical errors.

    CommentKind

    source

    The scanner: tokens, trivia and lexical errors.

    Constant

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    CustomType

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    DecodeError

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Definition

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    DefinitionCst

    source

    The CST: every token grouped per definition (ModuleCst::to_source() is the text byte for byte; a Skipped definition is a run the parser reported and skipped).

    DefinitionKind

    source

    The CST: every token grouped per definition (ModuleCst::to_source() is the text byte for byte; a Skipped definition is a run the parser reported and skipped).

    Deprecation

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Diagnostic

    source

    Diagnostics: severity, labels and the problem record.

    Dialect

    source

    Dialects: what the parser accepts (Dialect::gleam_1_19() is the default) and the deprecation Rules it warns about.

    Documentation

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Expr

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    External

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Function

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    FunctionLiteralKind

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ImplicitCallArgOrigin

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Import

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ImportAlias

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    IncorrectNamePosition

    source

    The parser: a module from tokens, with recovery per definition. A ParseResult holds the AST (module_), extra, warnings, the cst and the diagnostics; ParseError is what the snippet parsers raise.

    IntOperator

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Keyword

    source

    The scanner: tokens, trivia and lexical errors.

    Label

    source

    Diagnostics: severity, labels and the problem record.

    LexicalErrorType

    source

    The scanner: tokens, trivia and lexical errors.

    Module

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ModuleConstant

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ModuleCst

    source

    The CST: every token grouped per definition (ModuleCst::to_source() is the text byte for byte; a Skipped definition is a run the parser reported and skipped).

    ModuleExtra

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    OracleOutput

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    ParseError

    source

    The parser: a module from tokens, with recovery per definition. A ParseResult holds the AST (module_), extra, warnings, the cst and the diagnostics; ParseError is what the snippet parsers raise.

    ParseErrorDetails

    source

    The parser: a module from tokens, with recovery per definition. A ParseResult holds the AST (module_), extra, warnings, the cst and the diagnostics; ParseError is what the snippet parsers raise.

    ParseErrorType

    source

    The parser: a module from tokens, with recovery per definition. A ParseResult holds the AST (module_), extra, warnings, the cst and the diagnostics; ParseError is what the snippet parsers raise.

    ParseResult

    source

    The parser: a module from tokens, with recovery per definition. A ParseResult holds the AST (module_), extra, warnings, the cst and the diagnostics; ParseError is what the snippet parsers raise.

    Parsed

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Pattern

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Position

    source

    Spans (UTF-8 byte offsets) and positions (1-based line and column).

    Publicity

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    RecordBeingUpdated

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    RecordConstructor

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    RecordConstructorArg

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    RecordUpdateArg

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Rule

    source

    Dialects: what the parser accepts (Dialect::gleam_1_19() is the default) and the deprecation Rules it warns about.

    Severity

    source

    Diagnostics: severity, labels and the problem record.

    SourceText

    source

    Source text with byte, UTF-16 and line/column lookups.

    SpannedString

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    SrcSpan

    source

    Spans (UTF-8 byte offsets) and positions (1-based line and column).

    Statement

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    StringPrefixLeftSideAssignment

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TailPattern

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Target

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TargetedDefinition

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TodoKind

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Token

    source

    The scanner: tokens, trivia and lexical errors.

    TokenKind

    source

    The scanner: tokens, trivia and lexical errors.

    TokenStream

    source

    The scanner: tokens, trivia and lexical errors.

    Trivia

    source

    The scanner: tokens, trivia and lexical errors.

    TypeAlias

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAst

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAstConstructor

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAstConstructorName

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAstFn

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAstHole

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAstTuple

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    TypeAstVar

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    UnicodeEscapeError

    source

    The scanner: tokens, trivia and lexical errors.

    UnqualifiedImport

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Use

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    UseAssignment

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    Warning

    source

    The AST: a mirror of the Gleam compiler's untyped AST (v1.19.2), with canonical JSON (docs/ast-json.md).

    canonical

    source
    fn canonical(json : Json) -> String

    Canonical JSON text of an encoded AST value (sorted keys, no whitespace).

    decode_expr

    source

    decode_oracle_output

    source

    decode_parsed

    source

    diagnostic_description

    source
    fn diagnostic_description(code : String) -> String?

    The one-line description of a diagnostic code (GL-SCAN-001, …), or None for an unknown code. The table is in AGENTS.md > Diagnostics.

    encode_diagnostics

    source

    Diagnostics as JSON (gleam-parser's own shape).

    encode_expr

    source

    encode_oracle_output

    source

    encode_parsed

    source

    parse_float_value

    source
    fn parse_float_value(value : String) -> Double?

    The number a Float literal denotes (1., 1.e3, 1.0e-3, _).

    parse_int_value

    source
    fn parse_int_value(value : String) -> 
    BigInt    ?

    The number an Int literal denotes (sign, radix prefix, _ separators).

    parse_module

    source

    Parse a token stream into a module (see @parser.parse_module).

    parse_text

    source

    Parse Gleam source text into a module, with recovery per definition.

    test {
      let r = @gleam.parse_text("pub fn main() {\n  io.println(\"hi\")\n}\n")
      inspect(r.module_.definitions.length(), content="1")
      inspect(r.has_errors(), content="false")
    }

    render_plain

    source

    Render a diagnostic as the Gleam compiler prints it (no colours).

    render_terminal

    source

    Render a diagnostic with ANSI colours.

    tokenize

    source

    Scan source into tokens with trivia and diagnostics. The scan is lossless: TokenStream::to_source() is the text.

    tokenize_text

    source

    tokenize of a SourceText built from text.

    version

    source
    fn version() -> String

    The version of gleam-parser, the same as version in moon.mod. mise run release:prepare rewrites the string below; tests/bdd checks that it equals moon.mod.

    test {
      inspect(@gleam.version().split(".").count(), content="3")
    }

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