Frank.Rdf 7.3.3

Frank.Rdf

An rdf { } computation expression for hand-authoring RDF triples across one or more resources, serialized to JSON-LD in expanded form.

Zero ASP.NET Core dependency — no ProjectReference to Frank, no FrameworkReference to Microsoft.AspNetCore.App; the only NuGet dependency is dotNetRdf.Core. It builds and serializes documents; it has no opinion on how a handler returns the result.

Installation

dotnet add package Frank.Rdf

Example

open System
open Frank.Rdf

let players = Node.Iri "https://example.org/games/1#players"
let anonymousReview = Node.blank ()   // no natural IRI -- minted fresh, GUID-backed

let gameDoc =
    rdf {
        prefix "schema" "https://schema.org/"

        about (
            describe (Node.Iri "https://example.org/games/1") {
                typ "schema:Game"
                propertyString "schema:name" "Tic-tac-toe"
                propertyInt "schema:numberOfPlayers" 2
                propertyBool "schema:isFree" true
                propertyDateTime "schema:datePublished" (DateTimeOffset(1952, 1, 1, 0, 0, 0, TimeSpan.Zero))
                propertyNode "schema:sameAs" (Node.Iri "http://www.wikidata.org/entity/Q210339")
                propertyNode "schema:review" anonymousReview
            }
        )

        about (describe anonymousReview { propertyString "schema:reviewBody" "A timeless classic." })
    }

Doc.toJsonLd gameDoc

describe/about mirrors handler { }/get: describe subject { ... } runs to completion on its own, producing a plain Description, and about absorbs it into the surrounding rdf { } document — the same two-CE composition pattern Frank core already uses for handler { } feeding resource { }'s get. A bare triple subject predicate value operation is also available for one-off statements.

Node.blank () mints an anonymous node for values with no natural IRI (like the review above) — each call is GUID-backed, so blank nodes minted by two independently-built Docs never collide when merged via Doc.merge/includeDoc.

Available Operations

• prefix "name" "uri" - Declares a CURIE namespace mapping
• about (describe subject { ... }) - Absorbs a Description built by a nested describe { } block
• triple subject predicate value - Asserts a single statement directly
• includeDoc otherDoc - Merges another independently-built Doc in (same as Doc.merge)
• typ "prefix:Type" - Asserts rdf:type
• propertyString / propertyInt / propertyBool / propertyDateTime / propertyNode - Asserts a property, picked by the value's type (five distinct operations rather than one overloaded property, since F#'s custom-operation overload resolution can't reliably disambiguate by argument type across calls in the same block)
• Node.blank () - Mints a fresh, GUID-backed blank node for a subject/object with no natural IRI

Serializing

• Doc.toGraph doc - Builds a VDS.RDF.Graph
• Doc.writeJsonLd doc writer - Streams expanded-form JSON-LD into a System.IO.TextWriter (synchronous, flexible for any stream)
• Doc.writeJsonLdAsync doc bufferWriter - Streams expanded-form JSON-LD asynchronously into an IBufferWriter<byte> (e.g. HttpResponse.BodyWriter) — best for response streaming, encodes UTF8 directly to the buffer with no intermediate string allocation
• Doc.toJsonLd doc - Convenience wrapper returning the JSON-LD as a string

Output is always expanded-form JSON-LD: no @context, every predicate and type expanded to its absolute IRI. There is no compact-form option.

Choosing a serialization method

• Use writeJsonLdAsync when streaming to HTTP responses (most efficient, async-friendly)
• Use writeJsonLd when you have a TextWriter from a third-party API or need flexibility
• Use toJsonLd for testing, debugging, or when the full document fits in memory

Related Packages

Has no dependency on Frank, but is designed to serve JSON-LD documents from Frank resources — see sample/Frank.Rdf.Sample for a runnable demonstration, including Doc.merge folding shared facts (a publisher record) into each per-resource document.

See the project repository for the complete guide and sample applications.

License

MIT