feat!: mermaid rendering

src/lib.rs

@@ -63,10 +63,10 @@ use pyo3::prelude::*;
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
 
 pub mod algorithms;
-pub mod dot;
 pub mod hierarchy;
 pub mod multiportgraph;
 pub mod portgraph;
+pub mod render;
 pub mod secondary;
 pub mod unmanaged;
 pub mod view;

src/render.rs

@@ -0,0 +1,134 @@
+//! This module contains rendering logic from portgraphs into graphviz and
+//! mermaid diagrams.
+
+mod dot;
+mod mermaid;
+
+use std::borrow::Cow;
+
+pub use dot::{DotFormat, DotFormatter};
+pub use mermaid::{MermaidFormat, MermaidFormatter};
+
+use self::mermaid::encode_label;
+
+/// Style of a rendered edge.
+///
+/// Defaults to a box with no label.
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum NodeStyle {
+    /// Ignore the node. No edges will be connected to it.
+    Hidden,
+    /// Draw a box with the label inside.
+    Box(String),
+}
+
+impl NodeStyle {
+    /// Show a node label with the default style.
+    pub fn new(label: impl ToString) -> Self {
+        Self::Box(label.to_string())
+    }
+}
+
+impl Default for NodeStyle {
+    fn default() -> Self {
+        Self::Box(String::new())
+    }
+}
+
+/// Style of an edge in a rendered graph. Defaults to a box with no label.
+#[derive(Clone, Debug, PartialEq, Eq)]
+#[non_exhaustive]
+pub enum PortStyle {
+    /// Do not draw a label. Edges will be connected to the node.
+    Hidden,
+    /// Just the port label. Optionally prepend the port index.
+    Plain(String, bool),
+    /// Draw a box around the label. Optionally prepend the port index.
+    Boxed(String, bool),
+}
+
+impl PortStyle {
+    /// Show a port label with the default style.
+    pub fn new(label: impl ToString) -> Self {
+        Self::Boxed(label.to_string(), true)
+    }
+
+    /// Just the port label. Optionally prepend the port index.
+    pub fn text(label: impl ToString, show_offset: bool) -> Self {
+        Self::Plain(label.to_string(), show_offset)
+    }
+
+    /// Draw a box around the label. Optionally prepend the port index.
+    pub fn boxed(label: impl ToString, show_offset: bool) -> Self {
+        Self::Boxed(label.to_string(), show_offset)
+    }
+}
+
+impl Default for PortStyle {
+    fn default() -> Self {
+        Self::Boxed(String::new(), true)
+    }
+}
+
+/// Style of an edge in a rendered graph. Defaults to [`EdgeStyle::Solid`].
+#[derive(Clone, Debug, PartialEq, Eq, Default)]
+#[non_exhaustive]
+pub enum EdgeStyle {
+    /// Normal line
+    #[default]
+    Solid,
+    /// Dotted line
+    Dotted,
+    /// Dashed line
+    Dashed,
+    /// Custom style
+    Labelled(String, Box<EdgeStyle>),
+    /// Custom style
+    Custom(String),
+}
+
+impl EdgeStyle {
+    /// Adds a label to the edge style.
+    ///
+    /// If the edge style already has a label, it will be replaced.
+    pub fn with_label(self, label: impl ToString) -> Self {
+        match self {
+            Self::Labelled(_, e) => Self::Labelled(label.to_string(), e),
+            _ => Self::Labelled(label.to_string(), Box::new(self)),
+        }
+    }
+
+    /// Get the style as a graphviz style string
+    pub(super) fn as_dot_str(&self) -> &str {
+        match self {
+            Self::Solid => "",
+            Self::Dotted => "dotted",
+            Self::Dashed => "dashed",
+            Self::Custom(s) => s,
+            // Ignore edge labels.
+            Self::Labelled(_lbl, e) => e.as_dot_str(),
+        }
+    }
+
+    /// Get the style as a graphviz style string
+    pub(super) fn as_mermaid_str(&self) -> Cow<'_, str> {
+        match self {
+            Self::Solid => "-->".into(),
+            Self::Dotted => "-.->".into(),
+            // Dashed links are not supported in mermaid, we use dots instead.
+            Self::Dashed => "-.->".into(),
+            Self::Custom(s) => s.into(),
+            Self::Labelled(lbl, e) => {
+                let lbl = encode_label("", lbl);
+                match e.as_ref() {
+                    Self::Solid => format!("--{}-->", lbl).into(),
+                    Self::Dotted => format!("-.{}.->", lbl).into(),
+                    Self::Dashed => format!("-.{}.->", lbl).into(),
+                    Self::Custom(s) => s.into(),
+                    Self::Labelled(_, _) => panic!("Nested labelled edges are not supported"),
+                }
+            }
+        }
+    }
+}

src/dot.rs → src/render/dot.rs

@@ -4,98 +4,9 @@ use std::fmt::Display;
 
 use crate::{Direction, Hierarchy, LinkView, NodeIndex, PortIndex, Weights};
 
-/// Style of an edge in a dot graph. Defaults to "None".
-#[derive(Clone, Debug, PartialEq, Eq)]
-#[non_exhaustive]
-pub enum NodeStyle {
-    /// Ignore the node. No edges will be connected to it.
-    Hidden,
-    /// Draw a box with the label inside.
-    Box(String),
-}
-
-impl NodeStyle {
-    /// Show a node label with the default style.
-    pub fn new(label: impl ToString) -> Self {
-        Self::Box(label.to_string())
-    }
-}
-
-impl Default for NodeStyle {
-    fn default() -> Self {
-        Self::Box(String::new())
-    }
-}
-
-/// Style of an edge in a dot graph. Defaults to `Box("")`.
-#[derive(Clone, Debug, PartialEq, Eq)]
-#[non_exhaustive]
-pub enum PortStyle {
-    /// Do not draw a label. Edges will be connected to the node.
-    Hidden,
-    /// Just the port label. Optionally prepend the port index.
-    #[deprecated(note = "Use `PortStyle::Plain(_, true)` instead")]
-    Text(String),
-    /// Draw a box around the label. Optionally prepend the port index.
-    #[deprecated(note = "Use `PortStyle::Boxed(_, true)` instead")]
-    Box(String),
-    /// Just the port label. Optionally prepend the port index.
-    Plain(String, bool),
-    /// Draw a box around the label. Optionally prepend the port index.
-    Boxed(String, bool),
-}
-
-impl PortStyle {
-    /// Show a port label with the default style.
-    pub fn new(label: impl ToString) -> Self {
-        Self::Boxed(label.to_string(), true)
-    }
-
-    /// Just the port label. Optionally prepend the port index.
-    pub fn text(label: impl ToString, show_offset: bool) -> Self {
-        Self::Plain(label.to_string(), show_offset)
-    }
-
-    /// Draw a box around the label. Optionally prepend the port index.
-    pub fn boxed(label: impl ToString, show_offset: bool) -> Self {
-        Self::Boxed(label.to_string(), show_offset)
-    }
-}
+use super::{EdgeStyle, NodeStyle, PortStyle};
 
-impl Default for PortStyle {
-    fn default() -> Self {
-        Self::Boxed(String::new(), true)
-    }
-}
-
-/// Style of an edge in a dot graph. Defaults to [`EdgeStyle::Solid`].
-#[derive(Clone, Debug, PartialEq, Eq, Default)]
-#[non_exhaustive]
-pub enum EdgeStyle {
-    /// Normal line
-    #[default]
-    Solid,
-    /// Dotted line
-    Dotted,
-    /// Dashed line
-    Dashed,
-    /// Custom style
-    Custom(String),
-}
-
-impl EdgeStyle {
-    /// Get the style as a graphviz style string
-    pub fn as_str(&self) -> &str {
-        match self {
-            Self::Solid => "",
-            Self::Dotted => "dotted",
-            Self::Dashed => "dashed",
-            Self::Custom(s) => s,
-        }
-    }
-}
-
-/// Configurable dot formatter for a `PortGraph`.
+/// Configurable mermaid formatter for a `PortGraph`.
 pub struct DotFormatter<'g, G: LinkView> {
     graph: &'g G,
     forest: Option<&'g Hierarchy>,
@@ -148,6 +59,9 @@ where
     }
 
     /// Encode some `Weights` in the dot format.
+    ///
+    /// This is a convenience method to set the node and port styles based on the weight values.
+    /// It overrides any previous node or port style set.
     pub fn with_weights<'w, N, P>(self, weights: &'w Weights<N, P>) -> Self
     where
         'w: 'g,
@@ -266,18 +180,6 @@ where
                     style: String::new(),
                     label: make_label(offset, show_offset, &label),
                 }),
-                #[allow(deprecated)]
-                PortStyle::Text(label) => Some(PortCellStrings {
-                    id: format!("{}{}", dir, offset),
-                    style: "border=\"0\"".to_string(),
-                    label: make_label(offset, true, &label),
-                }),
-                #[allow(deprecated)]
-                PortStyle::Box(label) => Some(PortCellStrings {
-                    id: format!("{}{}", dir, offset),
-                    style: String::new(),
-                    label: make_label(offset, true, &label),
-                }),
             })
             .collect()
     }
@@ -313,7 +215,7 @@ where
         let to_node = self.graph.port_node(to).expect("missing node");
         let to_offset = self.graph.port_offset(to).expect("missing port").index();
         let edge_style = self.edge_style(from, to);
-        let edge_label = edge_style.as_str();
+        let edge_label = edge_style.as_dot_str();
         format!(
             "{}:out{} -> {}:in{} [style=\"{edge_label}\"]\n",
             from_node.index(),