feat: Add r4k script transfom target

src/transformations/mod.rs

@@ -1 +1,2 @@
 pub mod ode;
+pub mod r4k;

src/transformations/r4k.rs

@@ -0,0 +1,43 @@
+use minijinja::{context, Environment};
+
+use crate::Model;
+
+const ODE_PY_TEMPLATE: &str = include_str!("../../templates/ode.py.txt");
+
+pub fn render_ode(model: Model) -> String {
+    let env = Environment::new();
+
+    let mut ctx = context! {
+        model => model,
+    };
+
+    env.render_str(ODE_PY_TEMPLATE, &mut ctx).unwrap()
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_render_ode_abc_json() {
+        use super::*;
+
+        const ABC_JSON_STR: &str = include_str!("../../tests/fixtures/abc.json");
+
+        let model = serde_json::from_str::<Model>(ABC_JSON_STR).unwrap();
+
+        let ode = render_ode(model);
+
+        const EXPECTED: &str = r#"import numpy as np
+from numpy import float64, ndarray
+
+def system(t: float64, P: ndarray, *args):
+    A, B, C = P
+    
+    dA = (A  * B )
+    dB = (A  * B )
+    dC = (A  * B  / C )
+    
+    return ndarray([dA, dB, dC])"#;
+
+        assert_eq!(ode, EXPECTED);
+    }
+}

templates/ode.py.txt

@@ -0,0 +1,37 @@
+import numpy as np
+from numpy import float64, ndarray
+
+def system(t: float64, P: ndarray, *args):
+    {% for node_id, node in model.nodes|items if node.related_constant_name is defined -%}
+    {{ node.name }} {%- if not loop.last %}, {% endif %}
+    {%- endfor %} = P
+    {% for node_id, node in model.nodes|items -%}
+        {% if node.related_constant_name %}
+    d{{ node.name }} = {% for link in node.links -%}
+                {%- set link_node = model.nodes[link.node_id] -%}
+                {%- if link_node.related_constant_name -%}
+                    ({{ link.sign }} {{ link_node.name }})
+                {%- else -%}
+                    (
+                        {%- for input in link_node.inputs recursive -%}
+                            {%- set inner_link_node = model.nodes[input] %}
+                            {%- if inner_link_node.related_constant_name -%}
+                                {{ inner_link_node.name }} {% if not loop.last %} {{ link_node.operation }} {% endif %}
+                            {%- else -%}
+                                {%- set old_link_node = link_node -%}
+                                {%- set link_node = inner_link_node -%}
+                                {{ loop(inner_link_node.inputs) }}
+                                {%- set link_node = old_link_node -%}
+                                {% if not loop.last %} {{ link_node.operation }} {% endif %}
+                            {%- endif -%}
+                        {%- endfor -%}
+                    )
+                {%- endif -%}
+            {% endfor -%}
+        {% endif %}
+    {%- endfor %}
+
+    return ndarray([
+    {%- for node_id, node in model.nodes|items if node.related_constant_name is defined -%}
+    d{{ node.name }} {%- if not loop.last %}, {% endif %}
+    {%- endfor -%}])