Adding runner and world definition

src/world.rs

@@ -0,0 +1,45 @@
+use super::*;
+
+// A struct used for serializing / deserializing world
+#[derive(Debug, Serialize, Deserialize)]
+pub struct WorldDefinition {
+    pub tasks: HashMap<String, TaskDefinition>,
+
+    pub calendars: HashMap<String, Calendar>,
+
+    #[serde(default)]
+    pub variables: VarMap,
+
+    #[serde(default)]
+    pub output_options: TaskOutputOptions,
+}
+
+impl WorldDefinition {
+    pub fn taskset(&self) -> Result<TaskSet> {
+        // Ensure all tasks reference a valid calendar
+        for (name, def) in self.tasks.iter() {
+            if !self.calendars.contains_key(&def.calendar_name) {
+                return Err(anyhow!(
+                    "Task {} references calendar {}, which is not defined",
+                    name,
+                    def.calendar_name
+                ));
+            }
+        }
+        let tasks: HashMap<String, Task> = self
+            .tasks
+            .iter()
+            .map(|(tn, td)| {
+                (
+                    tn.clone(),
+                    td.to_task(self.calendars.get(&td.calendar_name).unwrap()),
+                )
+            })
+            .collect();
+        let ts = TaskSet::from(tasks);
+
+        ts.validate()?;
+
+        Ok(ts)
+    }
+}