Rework library interface

benches/run_iai.rs

@@ -5,15 +5,15 @@ mod setup;
 mod iai {
     use iai_callgrind::{library_benchmark, library_benchmark_group, main};
 
-    use scryer_prolog::QueryResolution;
+    use scryer_prolog::LeafAnswer;
 
     use super::setup;
 
     #[library_benchmark]
     #[bench::count_edges(setup::prolog_benches()["count_edges"].setup())]
     #[bench::numlist(setup::prolog_benches()["numlist"].setup())]
     #[bench::csv_codename(setup::prolog_benches()["csv_codename"].setup())]
-    fn bench(mut run: impl FnMut() -> QueryResolution) -> QueryResolution {
+    fn bench(mut run: impl FnMut() -> Vec<LeafAnswer>) -> Vec<LeafAnswer> {
         run()
     }
 

benches/setup.rs

@@ -1,7 +1,7 @@
 use std::{collections::BTreeMap, fs, path::Path};
 
 use maplit::btreemap;
-use scryer_prolog::{Machine, QueryResolution, Value};
+use scryer_prolog::{LeafAnswer, Machine, MachineBuilder, Term};
 
 pub fn prolog_benches() -> BTreeMap<&'static str, PrologBenchmark> {
     [
@@ -10,21 +10,21 @@ pub fn prolog_benches() -> BTreeMap<&'static str, PrologBenchmark> {
             "benches/edges.pl", // name of the prolog module file to load. use the same file in multiple benchmarks
             "independent_set_count(ky, Count).", // query to benchmark in the context of the loaded module. consider making the query adjustable to tune the run time to ~0.1s
             Strategy::Reuse,
-            btreemap! { "Count" => Value::Integer(2869176.into()) },
+            btreemap! { "Count" => Term::integer(2869176) },
         ),
         (
             "numlist",
             "benches/numlist.pl",
             "run_numlist(1000000, Head).",
             Strategy::Reuse,
-            btreemap! { "Head" => Value::Integer(1.into())},
+            btreemap! { "Head" => Term::integer(1) },
         ),
         (
             "csv_codename",
             "benches/csv.pl",
             "get_codename(\"0020\",Name).",
             Strategy::Reuse,
-            btreemap! { "Name" => Value::String("SPACE".into())},
+            btreemap! { "Name" => Term::string("SPACE") },
         ),
     ]
     .map(|b| {
@@ -54,7 +54,7 @@ pub struct PrologBenchmark {
     pub filename: &'static str,
     pub query: &'static str,
     pub strategy: Strategy,
-    pub bindings: BTreeMap<&'static str, Value>,
+    pub bindings: BTreeMap<&'static str, Term>,
 }
 
 impl PrologBenchmark {
@@ -64,28 +64,34 @@ impl PrologBenchmark {
             .file_stem()
             .and_then(|s| s.to_str())
             .unwrap();
-        let mut machine = Machine::new_lib();
+        let mut machine = MachineBuilder::default().build();
         machine.load_module_string(module_name, program);
         machine
     }
 
     #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
-    pub fn setup(&self) -> impl FnMut() -> QueryResolution {
+    pub fn setup(&self) -> impl FnMut() -> Vec<LeafAnswer> {
         let mut machine = self.make_machine();
         let query = self.query;
         move || {
             use criterion::black_box;
-            black_box(machine.run_query(black_box(query.to_string()))).unwrap()
+            black_box(
+                machine
+                    .run_query(black_box(query))
+                    .collect::<Result<Vec<_>, _>>()
+                    .unwrap(),
+            )
         }
     }
 }
 
 #[cfg(test)]
 mod test {
+
     #[test]
     fn validate_benchmarks() {
         use super::prolog_benches;
-        use scryer_prolog::{QueryMatch, QueryResolution};
+        use scryer_prolog::LeafAnswer;
         use std::{fmt::Write, fs};
 
         struct BenchResult {
@@ -100,10 +106,13 @@ mod test {
             let mut machine = r.make_machine();
             let setup_inference_count = machine.get_inference_count();
 
-            let result = machine.run_query(r.query.to_string()).unwrap();
+            let result: Vec<_> = machine
+                .run_query(r.query)
+                .collect::<Result<_, _>>()
+                .unwrap();
             let query_inference_count = machine.get_inference_count() - setup_inference_count;
 
-            let expected = QueryResolution::Matches(vec![QueryMatch::from(r.bindings.clone())]);
+            let expected = [LeafAnswer::from_bindings(r.bindings.clone())];
             assert_eq!(result, expected, "validating benchmark {}", r.name);
 
             results.push(BenchResult {

src/lib.rs

@@ -1,10 +1,9 @@
+//! A free software ISO Prolog system.
 #![recursion_limit = "4112"]
+#![deny(missing_docs)]
 
 #[macro_use]
 extern crate static_assertions;
-#[cfg(test)]
-#[macro_use]
-extern crate maplit;
 
 #[macro_use]
 pub(crate) mod macros;
@@ -46,24 +45,25 @@ use wasm_bindgen::prelude::*;
 // Re-exports
 pub use machine::config::*;
 pub use machine::lib_machine::*;
-pub use machine::parsed_results::*;
 pub use machine::Machine;
 
+/// Eval a source file in Wasm.
 #[cfg(target_arch = "wasm32")]
 #[wasm_bindgen]
 pub fn eval_code(s: &str) -> String {
     use machine::mock_wam::*;
 
     console_error_panic_hook::set_once();
 
-    let mut wam = Machine::with_test_streams();
+    let mut wam = MachineBuilder::default().build();
     let bytes = wam.test_load_string(s);
     String::from_utf8_lossy(&bytes).to_string()
 }
 
+/// The entry point for the Scryer Prolog CLI.
 pub fn run_binary() -> std::process::ExitCode {
     use crate::atom_table::Atom;
-    use crate::machine::{Machine, INTERRUPT};
+    use crate::machine::INTERRUPT;
 
     #[cfg(feature = "repl")]
     ctrlc::set_handler(move || {
@@ -84,7 +84,9 @@ pub fn run_binary() -> std::process::ExitCode {
         .unwrap();
 
     runtime.block_on(async move {
-        let mut wam = Machine::new(Default::default());
+        let mut wam = MachineBuilder::default()
+            .with_streams(StreamConfig::stdio())
+            .build();
         wam.run_module_predicate(atom!("$toplevel"), (atom!("$repl"), 0))
     })
 }

src/machine/config.rs

@@ -1,32 +1,191 @@
-pub struct MachineConfig {
-    pub streams: StreamConfig,
-    pub toplevel: &'static str,
+use rand::{rngs::StdRng, SeedableRng};
+
+use crate::Machine;
+
+use super::{
+    bootstrapping_compile, current_dir, import_builtin_impls, libraries, load_module, Atom,
+    CompilationTarget, IndexStore, ListingSource, MachineArgs, MachineState, Stream, StreamOptions,
+};
+
+/// Describes how the streams of a [`Machine`](crate::Machine) will be handled.
+pub struct StreamConfig {
+    inner: StreamConfigInner,
+}
+
+impl Default for StreamConfig {
+    /// Defaults to using in-memory streams.
+    fn default() -> Self {
+        Self::in_memory()
+    }
+}
+
+impl StreamConfig {
+    /// Binds the input, output and error streams to stdin, stdout and stderr.
+    pub fn stdio() -> Self {
+        StreamConfig {
+            inner: StreamConfigInner::Stdio,
+        }
+    }
+
+    /// Binds the output stream to a memory buffer, and the error stream to stderr.
+    ///
+    /// The input stream is ignored.
+    pub fn in_memory() -> Self {
+        StreamConfig {
+            inner: StreamConfigInner::Memory,
+        }
+    }
 }
 
-pub enum StreamConfig {
+enum StreamConfigInner {
     Stdio,
     Memory,
 }
 
-impl Default for MachineConfig {
+/// Describes how a [`Machine`](crate::Machine) will be configured.
+pub struct MachineBuilder {
+    pub(crate) streams: StreamConfig,
+    pub(crate) toplevel: &'static str,
+}
+
+impl Default for MachineBuilder {
+    /// Defaults to using in-memory streams.
     fn default() -> Self {
-        MachineConfig {
-            streams: StreamConfig::Stdio,
-            toplevel: include_str!("../toplevel.pl"),
+        MachineBuilder {
+            streams: Default::default(),
+            toplevel: default_toplevel(),
         }
     }
 }
 
-impl MachineConfig {
-    pub fn in_memory() -> Self {
-        MachineConfig {
-            streams: StreamConfig::Memory,
-            ..Default::default()
-        }
+impl MachineBuilder {
+    /// Creates a default configuration.
+    pub fn new() -> Self {
+        Default::default()
+    }
+
+    /// Uses the given `crate::StreamConfig` in this configuration.
+    pub fn with_streams(mut self, streams: StreamConfig) -> Self {
+        self.streams = streams;
+        self
     }
 
+    /// Uses the given toplevel in this configuration.
     pub fn with_toplevel(mut self, toplevel: &'static str) -> Self {
         self.toplevel = toplevel;
         self
     }
+
+    /// Builds the [`Machine`](crate::Machine) from this configuration.
+    pub fn build(self) -> Machine {
+        let args = MachineArgs::new();
+        let mut machine_st = MachineState::new();
+
+        let (user_input, user_output, user_error) = match self.streams.inner {
+            StreamConfigInner::Stdio => (
+                Stream::stdin(&mut machine_st.arena, args.add_history),
+                Stream::stdout(&mut machine_st.arena),
+                Stream::stderr(&mut machine_st.arena),
+            ),
+            StreamConfigInner::Memory => (
+                Stream::Null(StreamOptions::default()),
+                Stream::from_owned_string("".to_owned(), &mut machine_st.arena),
+                Stream::stderr(&mut machine_st.arena),
+            ),
+        };
+
+        let mut wam = Machine {
+            machine_st,
+            indices: IndexStore::new(),
+            code: vec![],
+            user_input,
+            user_output,
+            user_error,
+            load_contexts: vec![],
+            #[cfg(feature = "ffi")]
+            foreign_function_table: Default::default(),
+            rng: StdRng::from_entropy(),
+        };
+
+        let mut lib_path = current_dir();
+
+        lib_path.pop();
+        lib_path.push("lib");
+
+        wam.add_impls_to_indices();
+
+        bootstrapping_compile(
+            Stream::from_static_string(
+                libraries::get("ops_and_meta_predicates")
+                    .expect("library ops_and_meta_predicates should exist"),
+                &mut wam.machine_st.arena,
+            ),
+            &mut wam,
+            ListingSource::from_file_and_path(
+                atom!("ops_and_meta_predicates.pl"),
+                lib_path.clone(),
+            ),
+        )
+        .unwrap();
+
+        bootstrapping_compile(
+            Stream::from_static_string(
+                libraries::get("builtins").expect("library builtins should exist"),
+                &mut wam.machine_st.arena,
+            ),
+            &mut wam,
+            ListingSource::from_file_and_path(atom!("builtins.pl"), lib_path.clone()),
+        )
+        .unwrap();
+
+        if let Some(builtins) = wam.indices.modules.get_mut(&atom!("builtins")) {
+            load_module(
+                &mut wam.machine_st,
+                &mut wam.indices.code_dir,
+                &mut wam.indices.op_dir,
+                &mut wam.indices.meta_predicates,
+                &CompilationTarget::User,
+                builtins,
+            );
+
+            import_builtin_impls(&wam.indices.code_dir, builtins);
+        } else {
+            unreachable!()
+        }
+
+        lib_path.pop(); // remove the "lib" at the end
+
+        bootstrapping_compile(
+            Stream::from_static_string(include_str!("../loader.pl"), &mut wam.machine_st.arena),
+            &mut wam,
+            ListingSource::from_file_and_path(atom!("loader.pl"), lib_path.clone()),
+        )
+        .unwrap();
+
+        wam.configure_modules();
+
+        if let Some(loader) = wam.indices.modules.get(&atom!("loader")) {
+            load_module(
+                &mut wam.machine_st,
+                &mut wam.indices.code_dir,
+                &mut wam.indices.op_dir,
+                &mut wam.indices.meta_predicates,
+                &CompilationTarget::User,
+                loader,
+            );
+        } else {
+            unreachable!()
+        }
+
+        wam.load_special_forms();
+        wam.load_top_level(self.toplevel);
+        wam.configure_streams();
+
+        wam
+    }
+}
+
+/// Returns a static string slice to the default toplevel
+pub fn default_toplevel() -> &'static str {
+    include_str!("../toplevel.pl")
 }