Merge pull request #244 from egohygiene/copilot/introduce-transformation-dag-model

feat: introduce transformation DAG core model

Author: szmyty

Cargo.lock

@@ -49,6 +49,8 @@ notify-debouncer-mini = "0.4"
 
 itertools = "0.14"
 
+petgraph = "0.8"
+
 [package.metadata.generate-rpm]
 assets = [
     { source = "target/release/renderflow", dest = "/usr/bin/renderflow", mode = "0755" },

Cargo.toml

@@ -0,0 +1,76 @@
+use std::fmt;
+
+/// Represents all document formats that can participate in transformation edges.
+///
+/// Formats are modelled as graph nodes: each variant is a unique node in the
+/// [`TransformGraph`](super::TransformGraph).  An edge between two nodes
+/// indicates that a [`TransformEdge`](super::TransformEdge) exists that can
+/// convert from the source format to the target format.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum Format {
+    Markdown,
+    Html,
+    Pdf,
+    Docx,
+    Epub,
+    Rst,
+    Latex,
+}
+
+impl fmt::Display for Format {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let s = match self {
+            Format::Markdown => "markdown",
+            Format::Html => "html",
+            Format::Pdf => "pdf",
+            Format::Docx => "docx",
+            Format::Epub => "epub",
+            Format::Rst => "rst",
+            Format::Latex => "latex",
+        };
+        write!(f, "{}", s)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_display_markdown() {
+        assert_eq!(Format::Markdown.to_string(), "markdown");
+    }
+
+    #[test]
+    fn test_display_all_variants() {
+        assert_eq!(Format::Html.to_string(), "html");
+        assert_eq!(Format::Pdf.to_string(), "pdf");
+        assert_eq!(Format::Docx.to_string(), "docx");
+        assert_eq!(Format::Epub.to_string(), "epub");
+        assert_eq!(Format::Rst.to_string(), "rst");
+        assert_eq!(Format::Latex.to_string(), "latex");
+    }
+
+    #[test]
+    fn test_format_equality() {
+        assert_eq!(Format::Markdown, Format::Markdown);
+        assert_ne!(Format::Markdown, Format::Html);
+    }
+
+    #[test]
+    fn test_format_clone_copy() {
+        let f = Format::Pdf;
+        let g = f;
+        assert_eq!(f, g);
+    }
+
+    #[test]
+    fn test_format_hash() {
+        use std::collections::HashSet;
+        let mut set = HashSet::new();
+        set.insert(Format::Markdown);
+        set.insert(Format::Markdown);
+        set.insert(Format::Html);
+        assert_eq!(set.len(), 2);
+    }
+}