Add sample files, make it easier to find them

docs/assets/samples/foaf.jelly.txt

@@ -0,0 +1,189 @@
+# Frame 0
+rows {
+  options {
+    physical_type: PHYSICAL_STREAM_TYPE_TRIPLES
+    max_name_table_size: 4000
+    max_prefix_table_size: 150
+    max_datatype_table_size: 32
+    logical_type: LOGICAL_STREAM_TYPE_FLAT_TRIPLES
+    version: 1
+  }
+}
+rows {
+  prefix {
+    value: "https://neverblink.eu/example#"
+  }
+}
+rows {
+  name {
+    value: "Piotr"
+  }
+}
+rows {
+  prefix {
+    value: "http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+  }
+}
+rows {
+  name {
+    value: "type"
+  }
+}
+rows {
+  prefix {
+    value: "http://xmlns.com/foaf/0.1/"
+  }
+}
+rows {
+  name {
+    value: "Person"
+  }
+}
+rows {
+  triple {
+    s_iri {
+      prefix_id: 1
+    }
+    p_iri {
+      prefix_id: 2
+    }
+    o_iri {
+      prefix_id: 3
+    }
+  }
+}
+rows {
+  prefix {
+    value: "https://schema.org/"
+  }
+}
+rows {
+  triple {
+    o_iri {
+      prefix_id: 4
+      name_id: 3
+    }
+  }
+}
+rows {
+  name {
+    value: "givenName"
+  }
+}
+rows {
+  triple {
+    p_iri {
+      prefix_id: 3
+    }
+    o_literal {
+      lex: "Piotr"
+    }
+  }
+}
+rows {
+  name {
+    value: "familyName"
+  }
+}
+rows {
+  triple {
+    p_iri {
+    }
+    o_literal {
+      lex: "Sowi\305\204ski"
+    }
+  }
+}
+rows {
+  name {
+    value: "homepage"
+  }
+}
+rows {
+  prefix {
+    value: "https://"
+  }
+}
+rows {
+  name {
+    value: "ostrzyciel.eu"
+  }
+}
+rows {
+  triple {
+    p_iri {
+    }
+    o_iri {
+      prefix_id: 5
+    }
+  }
+}
+rows {
+  name {
+    value: "Organization"
+  }
+}
+rows {
+  triple {
+    s_bnode: "0000"
+    p_iri {
+      prefix_id: 2
+      name_id: 2
+    }
+    o_iri {
+      prefix_id: 4
+      name_id: 8
+    }
+  }
+}
+rows {
+  name {
+    value: "name"
+  }
+}
+rows {
+  triple {
+    p_iri {
+    }
+    o_literal {
+      lex: "NeverBlink"
+    }
+  }
+}
+rows {
+  name {
+    value: "url"
+  }
+}
+rows {
+  name {
+    value: "neverblink.eu"
+  }
+}
+rows {
+  triple {
+    p_iri {
+    }
+    o_iri {
+      prefix_id: 5
+    }
+  }
+}
+rows {
+  name {
+    value: "worksFor"
+  }
+}
+rows {
+  triple {
+    s_iri {
+      prefix_id: 1
+      name_id: 1
+    }
+    p_iri {
+      prefix_id: 4
+      name_id: 12
+    }
+    o_bnode: "0000"
+  }
+}

docs/assets/samples/foaf.ttl

@@ -0,0 +1,13 @@
+PREFIX foaf: <http://xmlns.com/foaf/0.1/>
+PREFIX schema: <https://schema.org/>
+PREFIX : <https://neverblink.eu/example#>
+
+:Piotr a foaf:Person , schema:Person ;
+    foaf:givenName "Piotr" ;
+    foaf:familyName "Sowiński" ;
+    foaf:homepage <https://ostrzyciel.eu> ;
+    schema:worksFor [
+        a schema:Organization ;
+        schema:name "NeverBlink" ;
+        schema:url <https://neverblink.eu>
+    ] .

docs/use-cases.md

@@ -45,6 +45,11 @@
 
 Below listed are some example datasets available in the Jelly format. All of these are in the [delimited format](user-guide.md#delimited-vs-non-delimited-jelly). The licenses for these datasets are specified on the linked documentation pages.
 
+- Toy dataset (starting example – `foaf.jelly`):
+    - [:octicons-download-24: foaf.jelly](assets/samples/foaf.jelly)
+    - [:octicons-download-24: foaf.ttl](assets/samples/foaf.ttl) – same file in the Turtle format.
+    - [:octicons-download-24: foaf.jelly.txt](assets/samples/foaf.jelly.txt) – text representation of the Jelly file, for debugging purposes.
+
 - Large datasets (millions of triples/quads):
     - [:octicons-download-24: ASSIST-IoT weather measurements](https://w3id.org/riverbench/datasets/assist-iot-weather/1.0.3/files/jelly_full.jelly.gz) ([documentation](https://w3id.org/riverbench/datasets/assist-iot-weather/1.0.3)) – 80 million triples.
     - [:octicons-download-24: 5 million nanopublications](https://w3id.org/riverbench/datasets/nanopubs/1.0.3/files/jelly_full.jelly.gz) ([documentation](https://w3id.org/riverbench/datasets/nanopubs/1.0.3)) – 171 million quads.

docs/user-guide.md

@@ -444,6 +444,16 @@ You can read more about how this works in the [serialization format specificatio
 - [Jelly-JVM]({{ jvm_link() }}) supports both variants, but uses them in different contexts. When writing to a Java byte stream (typically a file) with Apache Jena RIOT or RDF4J Rio, the delimited variant is used. However, the RIOT/Rio integrations can parse either delimited or non-delimited Jelly data. In the gRPC protocol, the non-delimited variant is used.
 - [RiverBench](http://w3id.org/riverbench) publishes its RDF metadata and datasets as Jelly files. These files are always written using the delimited variant.
 
+## Sample files
+
+`foaf.jelly` is a simple Jelly file that may be useful when trying to understand how the format works. You can download it here:
+
+- [:octicons-download-24: foaf.jelly](assets/samples/foaf.jelly)
+- [:octicons-download-24: foaf.ttl](assets/samples/foaf.ttl) – same file in the Turtle format.
+- [:octicons-download-24: foaf.jelly.txt](assets/samples/foaf.jelly.txt) – text representation of the Jelly file, for debugging purposes.
+
+You can find more example datasets (including ones with millions of triples) **[on this page](use-cases.md#example-datasets-in-the-jelly-format)**. The [conformance test cases](conformance/rdf-test-cases.md) contain dozens of valid Jelly files testing all features of the format.
+
 ## Implementing Jelly
 
 !!! note