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    moon_databridge

    Typed tabular import, validation and transformation

    databridge
    cli
    moonbit
    Download zip
    Author
    Version
    0.1.0
    License
    Apache-2.0
    Repository
    Last updated
    12 hours ago
    Downloads
    3

    #Moon DataBridge

    Tabular data pipelines, implemented in MoonBit with a JSON CLI and reusable library API.

    • Repository: https://github.com/btlqql/moon-databridge
    • Package: btlqql/moon_databridge@0.1.0
    • License: Apache-2.0
    • Release scope: 0.1.0 initial implementation. The broader competition proposal in docs/proposal.md is a reference design, not a claim that every planned capability is implemented.

    #Implemented

    CSV with escaped quotes and multiline fields; JSONL error isolation; typed column mapping with required/default/trim/lower/enum/range/scale constraints; row filters; composite-key deduplication; unique-key joins; deterministic sorting; grouped count/sum/mean; field profiling; CSV export.

    #Build and run

    Use MoonBit and Node.js 24. The core library supports JS, wasm, wasm-gc and native; the filesystem/HTTP/process CLI is JS only.

    moon update
moon build --target js
moon run cmd/main --target js -- examples/scenario-1.json
node _build/js/debug/build/cmd/main/main.js examples/scenario-1.json

    Pass - to read a UTF-8 JSON request from stdin. A single request must be at most 16 MiB. Successful requests print one JSON result; invalid requests exit nonzero. The host runner is a separate process and does not edit the input request file.

    #Library use

    moon add btlqql/moon_databridge@0.1.0

    In the consumer's moon.pkg:

    import {
      "btlqql/moon_databridge" @engine,
      "moonbitlang/core/json",
    }

    fn example(request : Json) -> Json raise {
      @engine.execute(request)
    }

    execute(Json) -> Json raise is the standard JSON boundary. from_json, Value::to_json, and run(Value) -> Value raise provide a typed semantic value interface. Object ordering is not significant; numeric values use finite Double. Public domain functions are listed in pkg.generated.mbti.

    #Tests

    moon test --target js
moon test --target wasm
moon test --target wasm-gc
moon test --target native  # requires a C compiler
moon build --target js
node scripts/check.mjs
python -B scripts/reference.py

    There are 8 checked fixture cases in tests/cases.json, executed both in MoonBit white-box tests and through the actual Node CLI. Independent reference checks use Python's standard library or separately written algorithms. Fixtures are synthetic and are not presented as production adoption evidence. See input and output examples and current boundaries.

    #Current boundaries

    Batch in memory. JSONL diagnostics preserve physical line numbers; transformation diagnostics use parsed row indices. Missing/null join keys and duplicate right keys are rejected. Arithmetic uses finite Double; decimal accounting and streaming are outside this release. Column order for CSV export must be explicit. The CSV reader is strict about quotes and column widths; malformed CSV rejects the batch.

    See source and dependency attribution. This release does not establish competition eligibility or organizer acceptance.

    InputError

    source
    pub(all) suberror InputError {
      InputError(String)
    } derive(Eq, Show)

    Value

    source
    pub(all) enum Value {
      Null
      Bool(Bool)
      Number(Double)
      String(String)
      Array(Array[Value])
      Object(Map[String, Value])
    } derive(Eq, 
    Debug    )

    Value::stringify

    source
    fn Value::stringify(self : Value) -> String

    Value::to_json

    source
    fn Value::to_json(self : Value) -> Json

    execute

    source
    fn execute(request : Json) -> Json raise

    from_json

    source
    fn from_json(value : Json) -> Value

    group_rows

    source
    fn group_rows(rows : Array[Value], keys : Array[String], value_field : String) -> Array[Value] raise InputError

    join_rows

    source
    fn join_rows(left : Array[Value], right : Array[Value], left_key : String, right_key : String, prefix? : String, inner? : Bool) -> Array[Value] raise InputError

    profile_rows

    source
    fn profile_rows(rows : Array[Value]) -> Value raise InputError

    read_csv

    source
    fn read_csv(source : String, delimiter? : Char) -> Array[Array[String]] raise InputError

    run

    source
    fn run(request : Value) -> Value raise

    write_csv

    source
    fn write_csv(rows : Array[Array[String]], delimiter? : String) -> String

    Source Files

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