Named graph example from the YARRRML spec fails to parse

[namedgraph]

Issue type: :bug: Bug

Mapping with graphs fails to parse. The tutorial and the spec seem suspect re. the graphs (plural) key, because in other examples I'm seeing graph (singular)?

Description

I'm following the 9.8.1 All triples example in order to place my output triples into a named graph:

mappings:
  ParentSmth:
    sources: RelatedSmth
    graphs: smth:$(id)
    s: smth:$(id)#this
    po:
      - p: ont:isSmthOf
        o:
          - mapping: ChildSmth

Steps

% yarrrml-parser -i RelatedSmth.yml -o RelatedSmth.ttl
TypeError: mapping.graphs.forEach is not a function
    at expandTargetsInMapping (/opt/homebrew/lib/node_modules/@rmlio/yarrrml-parser/lib/expander.js:235:20)
    at expandMappings (/opt/homebrew/lib/node_modules/@rmlio/yarrrml-parser/lib/expander.js:55:9)
    at expand (/opt/homebrew/lib/node_modules/@rmlio/yarrrml-parser/lib/expander.js:36:3)
    at RMLGenerator.convert (/opt/homebrew/lib/node_modules/@rmlio/yarrrml-parser/lib/abstract-generator.js:60:30)
    at Object.<anonymous> (/opt/homebrew/lib/node_modules/@rmlio/yarrrml-parser/bin/parser.js:106:23)
    at Module._compile (node:internal/modules/cjs/loader:1246:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1300:10)
    at Module.load (node:internal/modules/cjs/loader:1103:32)
    at Module._load (node:internal/modules/cjs/loader:942:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:83:12) {
  code: 'INVALID_YARRRML'
}

Environment

yarrrml-parser 1.4.0. openjdk 17.0.6 2023-01-17 OpenJDK Runtime Environment Homebrew (build 17.0.6+0) OpenJDK 64-Bit Server VM Homebrew (build 17.0.6+0, mixed mode, sharing)

[namedgraph]

graph key does what I need, so it looks like an error in the tutorial and the documentation?

[namedgraph]

@bjdmeest ping

[bjdmeest]

Ah yes, that's a small bug in the yarrrml-parser, yarrrml below works, but a fix is in the making

mappings:
  ParentSmth:
    sources: RelatedSmth
    graphs:
      - smth:$(id)
    s: smth:$(id)#this
    po:
      - p: ont:isSmthOf
        o:
          - mapping: ChildSmth

[bjdmeest]

this got fixed by v1.5.0: https://github.com/RMLio/yarrrml-parser/commit/a13aceb30b6334810d8703f944f0eaf25f2d4c9c