From 6b4e16e87940e7afdd0b5bb655e186b36a1a2be2 Mon Sep 17 00:00:00 2001
From: Pano Maria <pano.maria@gmail.com>
Date: Sat, 9 Nov 2024 07:03:58 +0100
Subject: [PATCH] introduce provided source (#91)

---
 spec/section/source-vocabulary.md | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/spec/section/source-vocabulary.md b/spec/section/source-vocabulary.md
index 1202dea..f04211a 100644
--- a/spec/section/source-vocabulary.md
+++ b/spec/section/source-vocabulary.md
@@ -456,3 +456,30 @@ specified by a string Literal. The file's absolute path is `/root/file.xml`.
   rml:iterator "$";
 .
 </pre>
+
+In some cases, it is useful to describe access to a source that will be programmatically
+provided to an RML processor at runtime.
+This could, for example, be a byte stream or an already deserialized JSON or XML node.
+
+For these cases, the `rml:ProvidedSource` can be used.
+It is a sub class of `rml:Source` and MUST have:
+
+* exactly one `rml:sourceIdentifier` property, whose value is a string literal, which
+uniquely identifies the source.
+
+| Property                | Domain                | Range      |
+| ------------------------| --------------------- | ---------- |
+| `rml:sourceIdentifier`  | `rml:ProvidedSource`  | `Literal`  |
+
+The following example illustrates a provided source with its unique identifier `myByteStream`:
+
+<pre class="ex-source">
+&lt;#ProvidedSource&gt; a rml:LogicalSource;
+  rml:source [ a rml:ProvidedSource;
+    rml:sourceIdentifier "myByteStream";
+  ];
+.
+</pre>
+
+An RML processor MAY offer a mechanism to programmatically provide a data source corresponding to
+the `rml:ProvidedSource` description.