WIP: refactor to generalize Machine::run_top_level()

src/machine/lib_machine.rs

@@ -0,0 +1,71 @@
+use super::{Machine, MachineConfig, QueryResult, QueryResultLine, Atom};
+
+impl Machine {
+    pub fn new_lib() -> Self {
+        Machine::new(MachineConfig::in_memory().with_toplevel(include_str!("../lib_toplevel.pl")))
+    }
+
+    pub fn run_query(&mut self, query: String) -> QueryResult {
+        self.set_user_input(query);
+        self.run_top_level(atom!("$toplevel"), (atom!("run_input_once"), 0));
+        self.parse_output()
+    }
+
+    pub fn parse_output(&self) -> QueryResult {
+        let output = self.get_user_output();
+        output
+            .split(";")
+            .map(|s| s.trim())
+            .map(|s| s.replace(".", ""))
+            .filter(|s| !s.is_empty())
+            .map(QueryResultLine::try_from)
+            .filter_map(Result::ok)
+            .collect::<Vec<QueryResultLine>>()
+            .into()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::machine::{QueryMatch, Value};
+
+    #[test]
+    fn programatic_query() {
+        let mut machine = Machine::with_test_streams();
+
+        machine.load_module_string(
+            "facts",
+            String::from(
+                r#"
+            triple("a", "p1", "b").
+            triple("a", "p2", "b").
+        "#,
+            ),
+        );
+
+        let query = String::from(r#"triple("a",P,"b")."#);
+        let output = machine.run_query(query);
+        assert_eq!(
+            output,
+            QueryResult::Matches(vec![
+                QueryMatch::from(btreemap! {
+                    "P" => Value::from("p1"),
+                }),
+                QueryMatch::from(btreemap! {
+                    "P" => Value::from("p2"),
+                }),
+            ])
+        );
+
+        assert_eq!(
+            machine.run_query(String::from(r#"triple("a","p1","b")."#)),
+            QueryResult::True
+        );
+
+        assert_eq!(
+            machine.run_query(String::from(r#"triple("x","y","z")."#)),
+            QueryResult::False
+        );
+    }
+}