yapyon (やぴょん)

「YAMLちゃうで。やぴょんやぴょん」 It's not YAML. It's yapyon.

Python-style typed literals with YAML-like block structure. Quoted strings, True/False/None, indentation blocks, - sequences, + multimaps, # comments — and parse-time splicing that replaces YAML's anchors.

name: "api-gateway"
version: 3.10
port: 8080
debug: False

paths:
  root: "/srv/gateway"
  logs: y"{root}/logs"          # -> "/srv/gateway/logs"
  banner: y"{name} v{version}"  # -> "api-gateway v3.10"   (lexeme, not 3.1)

changes:                        # multimap: keys may repeat, order is data
  + registry: {set: ["Bypass"]}
  + file: {delete: ["Edge"]}
  + registry: {remove: ["Edge Update"]}

The pitch: the same bytes mean the same data, to every parser, on every machine, always. No implicit typing (no is not False; there are no unquoted scalars at all), no anchors, no tags, no evaluation, one null spelling, one document per file. A repeated key is an error unless the block says + , so it can never be mistaken for a typo — or silently collapsed, the way Python and YAML both drop {"a": 1, "a": 2} down to one entry.

Status

Pre-alpha, and 0.1.0a1 means it. Lexer, parser, resolver and loader are done and tested — 265 tests, including a conformance suite that turns the splice matrix and the Python divergence table into executable cases.

The normative specification is still a working draft held by the author, so this README summarises the format rather than defining it.

$ pip install --pre yapyon

>>> import yapyon
>>> yapyon.loads('name: "gw"\nport: 8080\naddr: y"{name}:{port}"\n')
{'name': 'gw', 'port': 8080, 'addr': 'gw:8080'}

loads and load return plain Python. Eight of the ten types are builtins; a + block comes back as an OrderedMultimap, and a yt literal as an unfilled Template.

From a checkout, the stages will also dump what they see:

$ pip install -e ".[dev]" && pytest -q
$ python -m yapyon.lexer examples/gateway.ypy    # token dump
$ python -m yapyon.parser examples/gateway.ypy   # AST dump

Prefixes

f"...", t"...", u"..." are errors with hints — their meaning depends on an enclosing scope, and a data file has none.

Diagnostics

shiran: (warning) → akan: (error) → yakamashiwa: (internal bug). Verbose success prints ええやん.