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Parse Yaml

hexa.parse_yaml

Summary

Parse a hexa YAML spec into a :class:PortNode tree.

The YAML grammar uses a nested mapping format built from three member kinds:

  • attribute: a name: type scalar (e.g. source_type: str)
  • nested struct: a name: mapping of sub-attributes (e.g. source:)
  • port: a name: mapping whose single key is a class whose value is a body, or a class key with a ... body. A port carries a class shape.
Disambiguation of a mapping value

A mapping with exactly one key whose value is a non-scalar body (a mapping, ..., or a list) is a port. Any other mapping (multiple keys, or all scalar-typed values) is a nested struct of attributes.

Examples

Parse a spec into a port tree:

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```python
from hexa import parse_yaml

node = parse_yaml("samples/minimal/sample.yaml")
print(node)
```

The YAML grammar:

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```yaml
RootClassName:
  attr: type                 # scalar attribute
  source:                    # nested struct (all scalar sub-attributes)
    source_type: str
    bank: str
  methods:                   # reserved block of functions
    run:
      args: [a, b]
  ingest:                    # port (single non-scalar class key)
    IngestPort:
      source_type: str
      methods: {Method: ...}
```

Notes

  • See samples/minimal/sample.yaml and samples/extraction_pipeline/extraction_pipeline.yaml for worked examples.

Classes

Functions

parse_yaml 

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parse_yaml(path: str | Path) -> PortNode

Parse a hexa YAML spec file into a :class:PortNode tree.

Parameters:

Name Type Description Default
path str | Path

Path to the .yaml file.

 required

Returns:

Name Type Description
PortNode PortNode

The root node of the parsed tree.

Raises:

Type Description
ValueError

On structural errors in the YAML.