862 lines
28 KiB
Rust
862 lines
28 KiB
Rust
use prolog_parser::ast::*;
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use prolog_parser::tabled_rc::*;
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use crate::prolog::clause_types::*;
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use crate::prolog::forms::*;
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use crate::prolog::heap_print::*;
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use crate::prolog::instructions::*;
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use crate::prolog::machine::heap::Heap;
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use crate::prolog::read::*;
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mod attributed_variables;
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pub(super) mod code_repo;
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pub mod compile;
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mod copier;
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mod dynamic_database;
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pub mod heap;
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pub mod machine_errors;
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pub mod machine_indices;
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pub(super) mod machine_state;
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pub mod modules;
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mod stack;
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pub(super) mod term_expansion;
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pub mod toplevel;
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#[macro_use]
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mod machine_state_impl;
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mod system_calls;
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use crate::prolog::machine::attributed_variables::*;
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use crate::prolog::machine::code_repo::*;
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use crate::prolog::machine::compile::*;
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use crate::prolog::machine::machine_errors::*;
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use crate::prolog::machine::machine_indices::*;
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use crate::prolog::machine::machine_state::*;
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use crate::prolog::machine::modules::*;
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use crate::prolog::machine::toplevel::*;
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use crate::prolog::read::PrologStream;
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use indexmap::IndexMap;
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use std::collections::VecDeque;
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use std::fs::File;
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use std::io::Read;
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use std::mem;
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use std::ops::Index;
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use std::rc::Rc;
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use std::sync::atomic::AtomicBool;
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pub struct MachinePolicies {
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call_policy: Box<dyn CallPolicy>,
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cut_policy: Box<dyn CutPolicy>,
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}
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lazy_static! {
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pub static ref INTERRUPT: AtomicBool = AtomicBool::new(false);
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}
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impl MachinePolicies {
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#[inline]
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fn new() -> Self {
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MachinePolicies {
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call_policy: Box::new(DefaultCallPolicy {}),
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cut_policy: Box::new(DefaultCutPolicy {}),
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}
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}
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}
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pub struct Machine {
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pub(super) machine_st: MachineState,
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pub(super) inner_heap: Heap,
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pub(super) policies: MachinePolicies,
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pub(super) indices: IndexStore,
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pub(super) code_repo: CodeRepo,
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pub(super) toplevel_idx: usize,
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pub(super) prolog_stream: ParsingStream<Box<dyn Read>>,
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}
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impl Index<LocalCodePtr> for CodeRepo {
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type Output = Line;
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fn index(&self, ptr: LocalCodePtr) -> &Self::Output {
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match ptr {
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LocalCodePtr::InSituDirEntry(p) => &self.in_situ_code[p],
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LocalCodePtr::TopLevel(_, p) => &self.cached_query[p],
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LocalCodePtr::DirEntry(p) => &self.code[p],
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LocalCodePtr::UserGoalExpansion(p) => &self.goal_expanders[p],
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LocalCodePtr::UserTermExpansion(p) => &self.term_expanders[p],
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}
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}
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}
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impl Index<LocalCodePtr> for Machine {
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type Output = Line;
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fn index(&self, ptr: LocalCodePtr) -> &Self::Output {
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&self.code_repo[ptr]
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}
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}
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impl SubModuleUser for IndexStore {
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fn atom_tbl(&self) -> TabledData<Atom> {
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self.atom_tbl.clone()
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}
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fn op_dir(&mut self) -> &mut OpDir {
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&mut self.op_dir
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}
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fn get_code_index(&self, key: PredicateKey, module_name: ClauseName) -> Option<CodeIndex> {
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match module_name.as_str() {
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"user" | "builtin" => self.code_dir.get(&key).cloned(),
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_ => self
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.modules
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.get(&module_name)
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.and_then(|ref module| module.code_dir.get(&key).cloned().map(CodeIndex::from))
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}
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}
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fn remove_code_index(&mut self, key: PredicateKey) {
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self.code_dir.remove(&key);
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}
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fn insert_dir_entry(&mut self, name: ClauseName, arity: usize, idx: CodeIndex) {
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if let Some(ref code_idx) = self.code_dir.get(&(name.clone(), arity)) {
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if !code_idx.is_undefined() {
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println!("Warning: overwriting {}/{}", &name, arity);
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}
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let (p, module_name) = idx.0.borrow().clone();
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set_code_index!(code_idx, p, module_name);
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return;
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}
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self.code_dir.insert((name.clone(), arity), idx.clone());
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}
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fn use_qualified_module(
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&mut self,
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code_repo: &mut CodeRepo,
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flags: MachineFlags,
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submodule: &Module,
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exports: &Vec<ModuleExport>,
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) -> Result<(), SessionError> {
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use_qualified_module(self, submodule, exports)?;
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submodule
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.dump_expansions(code_repo, flags)
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.map_err(SessionError::from)
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}
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fn use_module(
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&mut self,
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code_repo: &mut CodeRepo,
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flags: MachineFlags,
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submodule: &Module,
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) -> Result<(), SessionError> {
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use_module(self, submodule)?;
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if !submodule.inserted_expansions {
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submodule
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.dump_expansions(code_repo, flags)
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.map_err(SessionError::from)
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} else {
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Ok(())
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}
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}
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}
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include!(concat!(env!("OUT_DIR"), "/libraries.rs"));
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static TOPLEVEL: &str = include_str!("../toplevel.pl");
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impl Machine {
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fn compile_special_forms(&mut self) {
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let verify_attrs_src = clause_name!("verify_attrs.pl");
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let project_attrs_src = clause_name!("project_attributes.pl");
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match compile_special_form(self, parsing_stream(VERIFY_ATTRS.as_bytes()), verify_attrs_src)
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{
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Ok(p) => {
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self.machine_st.attr_var_init.verify_attrs_loc = p;
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}
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Err(_) =>
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panic!("Machine::compile_special_forms() failed at VERIFY_ATTRS"),
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}
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match compile_special_form(self, parsing_stream(PROJECT_ATTRS.as_bytes()), project_attrs_src)
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{
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Ok(p) => {
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self.machine_st.attr_var_init.project_attrs_loc = p;
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}
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Err(e) =>
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panic!("Machine::compile_special_forms() failed at PROJECT_ATTRS: {}", e),
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}
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}
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fn compile_top_level(&mut self) -> Result<(), SessionError>
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{
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self.toplevel_idx = self.code_repo.code.len();
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compile_user_module(self, parsing_stream(TOPLEVEL.as_bytes()),
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true, clause_name!("toplevel.pl"));
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if let Some(module) = self.indices.take_module(clause_name!("$toplevel")) {
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self.indices.use_module(
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&mut self.code_repo,
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self.machine_st.flags,
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&module,
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)?;
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Ok(self.indices.insert_module(module))
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} else {
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Err(SessionError::ModuleNotFound)
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}
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}
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fn compile_scryerrc(&mut self) {
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let mut path = match dirs::home_dir() {
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Some(path) => path,
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None => return,
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};
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path.push(".scryerrc");
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if path.is_file() {
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let file_src = match File::open(&path) {
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Ok(file_handle) => parsing_stream(file_handle),
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Err(_) => return,
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};
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compile_user_module(self, file_src, true,
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clause_name!("$HOME/.scryerrc"));
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}
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}
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#[cfg(test)]
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pub fn reset(&mut self) {
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self.prolog_stream = readline::input_stream();
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self.policies.cut_policy = Box::new(DefaultCutPolicy {});
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self.machine_st.reset();
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}
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pub fn run_init_code(&mut self, code: Code) -> bool {
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let old_machine_st = self.sink_to_snapshot();
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self.machine_st.reset();
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self.code_repo.cached_query = code;
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self.run_query();
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let result = self.machine_st.fail;
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self.absorb_snapshot(old_machine_st);
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!result
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}
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pub fn run_top_level(&mut self) {
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use std::env;
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let mut filename_atoms = vec![];
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// the first of these is the path to the scryer-prolog executable, so skip
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// it.
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for filename in env::args().skip(1) {
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let atom = atom!(filename, self.indices.atom_tbl);
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filename_atoms.push(Addr::Con(atom));
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}
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let list_addr =
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Addr::HeapCell(self.machine_st.heap.to_list(filename_atoms.into_iter()));
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self.machine_st[temp_v!(1)] = list_addr;
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self.machine_st.p = CodePtr::Local(LocalCodePtr::DirEntry(self.toplevel_idx));
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self.run_query();
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}
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pub fn new(prolog_stream: PrologStream) -> Self {
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let mut wam = Machine {
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machine_st: MachineState::new(),
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inner_heap: Heap::with_capacity(256 * 256),
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policies: MachinePolicies::new(),
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indices: IndexStore::new(),
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code_repo: CodeRepo::new(),
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toplevel_idx: 0,
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prolog_stream,
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};
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let atom_tbl = wam.indices.atom_tbl.clone();
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compile_listing(
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&mut wam,
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parsing_stream(BUILTINS.as_bytes()),
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default_index_store!(atom_tbl.clone()),
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true,
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clause_name!("builtins.pl"),
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);
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wam.compile_special_forms();
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compile_user_module(&mut wam, parsing_stream(ERROR.as_bytes()), true,
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clause_name!("error"));
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compile_user_module(&mut wam, parsing_stream(LISTS.as_bytes()), true,
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clause_name!("lists"));
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compile_user_module(&mut wam, parsing_stream(NON_ISO.as_bytes()), true,
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clause_name!("non_iso"));
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compile_user_module(&mut wam, parsing_stream(SI.as_bytes()), true,
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clause_name!("si"));
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if wam.compile_top_level().is_err() {
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panic!("Loading '$toplevel' module failed");
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}
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wam.compile_scryerrc();
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wam
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}
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#[inline]
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pub fn machine_flags(&self) -> MachineFlags {
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self.machine_st.flags
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}
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pub fn check_toplevel_code(&self, indices: &IndexStore) -> Result<(), SessionError> {
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for (key, idx) in &indices.code_dir {
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match ClauseType::from(key.0.clone(), key.1, None) {
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ClauseType::Named(..) | ClauseType::Op(..) => {}
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_ => {
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// ensure we don't try to overwrite the name/arity of a builtin.
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let err_str = format!("{}/{}", key.0, key.1);
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let err_str = clause_name!(err_str, self.indices.atom_tbl());
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return Err(SessionError::CannotOverwriteBuiltIn(err_str));
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}
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};
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if let Some(ref existing_idx) = self.indices.code_dir.get(&key) {
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// ensure we don't try to overwrite an existing predicate from a different module.
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if !existing_idx.is_undefined() && !idx.is_undefined() {
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// allow the overwriting of user-level predicates by all other predicates.
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if existing_idx.module_name().as_str() == "user" {
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continue;
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}
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if existing_idx.module_name() != idx.module_name() {
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let err_str = format!(
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"{}/{} from module {}",
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key.0,
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key.1,
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existing_idx.module_name().as_str()
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);
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let err_str = clause_name!(err_str, self.indices.atom_tbl());
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return Err(SessionError::CannotOverwriteImport(err_str));
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}
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}
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}
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}
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Ok(())
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}
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pub fn add_batched_code(&mut self, code: Code, code_dir: CodeDir) {
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// error detection has finished, so update the master index of keys.
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for (key, idx) in code_dir {
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if let Some(ref mut master_idx) = self.indices.code_dir.get_mut(&key) {
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// ensure we don't double borrow if master_idx == idx.
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// we don't need to modify anything in that case.
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if !Rc::ptr_eq(&master_idx.0, &idx.0) {
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set_code_index!(master_idx, idx.0.borrow().0, idx.module_name());
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}
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continue;
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}
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self.indices.code_dir.insert(key, idx);
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}
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self.code_repo.code.extend(code.into_iter());
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}
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#[inline]
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pub fn add_batched_ops(&mut self, op_dir: OpDir) {
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self.indices.op_dir.extend(op_dir.into_iter());
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}
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#[inline]
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pub fn add_module(&mut self, module: Module, code: Code) {
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self.indices
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.modules
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.insert(module.module_decl.name.clone(), module);
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self.code_repo.code.extend(code.into_iter());
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}
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fn throw_session_error(&mut self, err: SessionError, key: PredicateKey) {
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let h = self.machine_st.heap.h;
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let err = MachineError::session_error(h, err);
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let stub = MachineError::functor_stub(key.0, key.1);
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let err = self.machine_st.error_form(err, stub);
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self.machine_st.throw_exception(err);
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return;
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}
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fn extract_module_export_list(&mut self) -> Result<Vec<ModuleExport>, ParserError>
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{
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let mut export_list = self.machine_st[temp_v!(2)].clone();
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let mut exports = vec![];
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while let Addr::Lis(l) = self.machine_st.store(self.machine_st.deref(export_list)) {
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match &self.machine_st.heap[l] {
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&HeapCellValue::Addr(Addr::Str(s)) => {
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match &self.machine_st.heap[s] {
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HeapCellValue::NamedStr(arity, ref name, _)
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if *arity == 2 && name.as_str() == "/" => {
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let name = match &self.machine_st.heap[s+1] {
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&HeapCellValue::Addr(Addr::Con(Constant::Atom(ref name, _))) =>
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name.clone(),
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_ =>
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unreachable!()
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};
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let arity = match &self.machine_st.heap[s+2] {
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&HeapCellValue::Addr(Addr::Con(Constant::Integer(ref arity))) =>
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arity.to_usize().unwrap(),
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_ =>
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unreachable!()
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};
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exports.push(ModuleExport::PredicateKey((name, arity)));
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}
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HeapCellValue::NamedStr(arity, ref name, _)
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if *arity == 3 && name.as_str() == "op" => {
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let name = match &self.machine_st.heap[s+3] {
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&HeapCellValue::Addr(Addr::Con(Constant::Atom(ref name, _))) =>
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name.clone(),
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_ =>
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unreachable!()
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};
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let spec = match &self.machine_st.heap[s+2] {
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&HeapCellValue::Addr(Addr::Con(Constant::Atom(ref name, _))) =>
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name.clone(),
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_ =>
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unreachable!()
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};
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let prec = match &self.machine_st.heap[s+1] {
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&HeapCellValue::Addr(Addr::Con(Constant::Integer(ref arity))) =>
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arity.to_usize().unwrap(),
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_ =>
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unreachable!()
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};
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exports.push(ModuleExport::OpDecl(to_op_decl(
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prec,
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spec.as_str(),
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name,
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)?));
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}
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_ => unreachable!()
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}
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}
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_ => unreachable!()
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}
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export_list = self.machine_st.heap[l+1].as_addr(l+1);
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}
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Ok(exports)
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}
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fn use_module<ToSource>(&mut self, to_src: ToSource)
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where ToSource: Fn(ClauseName) -> ModuleSource
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{
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// the term expander will overwrite the cached query, so save it here.
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let cached_query = mem::replace(&mut self.code_repo.cached_query, vec![]);
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let module_spec = self.machine_st[temp_v!(1)].clone();
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let name = match self.machine_st.store(self.machine_st.deref(module_spec)) {
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Addr::Con(Constant::Atom(name, _)) => name,
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_ => unreachable!()
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};
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let load_result = match to_src(name) {
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ModuleSource::Library(name) =>
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if let Some(module) = self.indices.take_module(name.clone()) {
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self.indices.remove_module(clause_name!("user"), &module);
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self.indices.modules.insert(name.clone(), module);
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Ok(name)
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} else {
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load_library(self, name, false)
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},
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ModuleSource::File(name) =>
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load_module_from_file(self, name.as_str(), false)
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};
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let result = load_result.and_then(|name| {
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let module = self.indices.take_module(name.clone()).unwrap();
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if !module.is_impromptu_module {
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self.indices.use_module(&mut self.code_repo, self.machine_st.flags, &module)?;
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}
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Ok(self.indices.insert_module(module))
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});
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self.code_repo.cached_query = cached_query;
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if let Err(e) = result {
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self.throw_session_error(e, (clause_name!("use_module"), 1));
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}
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}
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fn use_qualified_module<ToSource>(&mut self, to_src: ToSource)
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where ToSource: Fn(ClauseName) -> ModuleSource
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{
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// the term expander will overwrite the cached query, so save it here.
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let cached_query = mem::replace(&mut self.code_repo.cached_query, vec![]);
|
|
|
|
let module_spec = self.machine_st[temp_v!(1)].clone();
|
|
let name = match self.machine_st.store(self.machine_st.deref(module_spec)) {
|
|
Addr::Con(Constant::Atom(name, _)) => name,
|
|
_ => unreachable!()
|
|
};
|
|
|
|
let exports = match self.extract_module_export_list() {
|
|
Ok(exports) => exports,
|
|
Err(e) => {
|
|
self.throw_session_error(SessionError::from(e), (clause_name!("use_module"), 2));
|
|
return;
|
|
}
|
|
};
|
|
|
|
let load_result = match to_src(name) {
|
|
ModuleSource::Library(name) =>
|
|
if let Some(module) = self.indices.take_module(name.clone()) {
|
|
self.indices.remove_module(clause_name!("user"), &module);
|
|
self.indices.modules.insert(name.clone(), module);
|
|
|
|
Ok(name)
|
|
} else {
|
|
load_library(self, name, false)
|
|
},
|
|
ModuleSource::File(name) =>
|
|
load_module_from_file(self, name.as_str(), false)
|
|
};
|
|
|
|
let result = load_result.and_then(|name| {
|
|
let module = self.indices.take_module(name.clone()).unwrap();
|
|
|
|
if !module.is_impromptu_module {
|
|
self.indices.use_qualified_module(&mut self.code_repo,
|
|
self.machine_st.flags,
|
|
&module,
|
|
&exports)?;
|
|
}
|
|
|
|
Ok(self.indices.insert_module(module))
|
|
});
|
|
|
|
self.code_repo.cached_query = cached_query;
|
|
|
|
if let Err(e) = result {
|
|
self.throw_session_error(e, (clause_name!("use_module"), 2));
|
|
}
|
|
}
|
|
|
|
fn handle_toplevel_command(&mut self, code_ptr: REPLCodePtr, p: LocalCodePtr) {
|
|
match code_ptr {
|
|
REPLCodePtr::CompileBatch => {
|
|
let user_src = clause_name!("user");
|
|
|
|
let src = readline::input_stream();
|
|
readline::set_prompt(false);
|
|
|
|
if let EvalSession::Error(e) = compile_user_module(self, src, false, user_src) {
|
|
self.throw_session_error(e, (clause_name!("repl"), 0));
|
|
}
|
|
}
|
|
REPLCodePtr::UseModule =>
|
|
self.use_module(ModuleSource::Library),
|
|
REPLCodePtr::UseModuleFromFile =>
|
|
self.use_module(ModuleSource::File),
|
|
REPLCodePtr::UseQualifiedModule =>
|
|
self.use_qualified_module(ModuleSource::Library),
|
|
REPLCodePtr::UseQualifiedModuleFromFile =>
|
|
self.use_qualified_module(ModuleSource::File)
|
|
}
|
|
|
|
self.machine_st.p = CodePtr::Local(p);
|
|
}
|
|
|
|
fn sink_to_snapshot(&mut self) -> MachineState {
|
|
let mut snapshot = MachineState::with_capacity(0);
|
|
|
|
snapshot.hb = self.machine_st.hb;
|
|
snapshot.e = self.machine_st.e;
|
|
snapshot.b = self.machine_st.b;
|
|
snapshot.b0 = self.machine_st.b0;
|
|
snapshot.s = self.machine_st.s;
|
|
snapshot.tr = self.machine_st.tr;
|
|
snapshot.pstr_tr = self.machine_st.pstr_tr;
|
|
snapshot.num_of_args = self.machine_st.num_of_args;
|
|
|
|
snapshot.fail = self.machine_st.fail;
|
|
snapshot.trail = mem::replace(&mut self.machine_st.trail, vec![]);
|
|
snapshot.pstr_trail = mem::replace(&mut self.machine_st.pstr_trail, vec![]);
|
|
snapshot.heap = self.machine_st.heap.take();
|
|
snapshot.mode = self.machine_st.mode;
|
|
snapshot.stack = self.machine_st.stack.take();
|
|
snapshot.registers = mem::replace(&mut self.machine_st.registers, vec![]);
|
|
snapshot.block = self.machine_st.block;
|
|
|
|
snapshot.ball = self.machine_st.ball.take();
|
|
snapshot.lifted_heap = mem::replace(&mut self.machine_st.lifted_heap, vec![]);
|
|
|
|
snapshot
|
|
}
|
|
|
|
fn absorb_snapshot(&mut self, mut snapshot: MachineState) {
|
|
self.machine_st.hb = snapshot.hb;
|
|
self.machine_st.e = snapshot.e;
|
|
self.machine_st.b = snapshot.b;
|
|
self.machine_st.b0 = snapshot.b0;
|
|
self.machine_st.s = snapshot.s;
|
|
self.machine_st.tr = snapshot.tr;
|
|
self.machine_st.pstr_tr = snapshot.pstr_tr;
|
|
self.machine_st.num_of_args = snapshot.num_of_args;
|
|
|
|
self.machine_st.fail = snapshot.fail;
|
|
self.machine_st.trail = mem::replace(&mut snapshot.trail, vec![]);
|
|
self.machine_st.pstr_trail = mem::replace(&mut snapshot.pstr_trail, vec![]);
|
|
|
|
self.inner_heap = self.machine_st.heap.take();
|
|
self.inner_heap.truncate(0);
|
|
|
|
self.machine_st.heap = snapshot.heap.take();
|
|
self.machine_st.mode = snapshot.mode;
|
|
self.machine_st.stack = snapshot.stack;
|
|
self.machine_st.registers = mem::replace(&mut snapshot.registers, vec![]);
|
|
self.machine_st.block = snapshot.block;
|
|
|
|
self.machine_st.ball = snapshot.ball.take();
|
|
self.machine_st.lifted_heap = mem::replace(&mut snapshot.lifted_heap, vec![]);
|
|
}
|
|
|
|
pub(super) fn run_query(&mut self) {
|
|
self.machine_st.cp = LocalCodePtr::TopLevel(0, self.code_repo.size_of_cached_query());
|
|
let end_ptr = CodePtr::Local(self.machine_st.cp);
|
|
|
|
while self.machine_st.p < end_ptr {
|
|
self.machine_st.query_stepper(
|
|
&mut self.indices,
|
|
&mut self.policies,
|
|
&mut self.code_repo,
|
|
&mut self.prolog_stream,
|
|
);
|
|
|
|
match self.machine_st.p {
|
|
CodePtr::Local(LocalCodePtr::TopLevel(_, p)) if p > 0 => {}
|
|
CodePtr::REPL(code_ptr, p) => self.handle_toplevel_command(code_ptr, p),
|
|
CodePtr::DynamicTransaction(trans_type, p) => {
|
|
// self.code_repo.cached_query is about to be overwritten by the term expander,
|
|
// so hold onto it locally and restore it after the compiler has finished.
|
|
self.machine_st.fail = false;
|
|
let cached_query = mem::replace(&mut self.code_repo.cached_query, vec![]);
|
|
|
|
self.dynamic_transaction(trans_type, p);
|
|
self.code_repo.cached_query = cached_query;
|
|
|
|
if let CodePtr::Local(LocalCodePtr::TopLevel(_, 0)) = self.machine_st.p {
|
|
break;
|
|
}
|
|
}
|
|
_ =>
|
|
break
|
|
};
|
|
}
|
|
}
|
|
}
|
|
|
|
impl MachineState {
|
|
fn dispatch_instr(
|
|
&mut self,
|
|
instr: &Line,
|
|
indices: &mut IndexStore,
|
|
policies: &mut MachinePolicies,
|
|
code_repo: &CodeRepo,
|
|
prolog_stream: &mut PrologStream,
|
|
) {
|
|
match instr {
|
|
&Line::Arithmetic(ref arith_instr) => self.execute_arith_instr(arith_instr),
|
|
&Line::Choice(ref choice_instr) => {
|
|
self.execute_choice_instr(choice_instr, &mut policies.call_policy)
|
|
}
|
|
&Line::Cut(ref cut_instr) => {
|
|
self.execute_cut_instr(cut_instr, &mut policies.cut_policy)
|
|
}
|
|
&Line::Control(ref control_instr) => self.execute_ctrl_instr(
|
|
indices,
|
|
code_repo,
|
|
&mut policies.call_policy,
|
|
&mut policies.cut_policy,
|
|
prolog_stream,
|
|
control_instr,
|
|
),
|
|
&Line::Fact(ref fact_instr) => {
|
|
self.execute_fact_instr(&fact_instr);
|
|
self.p += 1;
|
|
}
|
|
&Line::Indexing(ref indexing_instr) => self.execute_indexing_instr(&indexing_instr),
|
|
&Line::IndexedChoice(ref choice_instr) => {
|
|
self.execute_indexed_choice_instr(choice_instr, &mut policies.call_policy)
|
|
}
|
|
&Line::Query(ref query_instr) => {
|
|
self.execute_query_instr(&query_instr);
|
|
self.p += 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
fn execute_instr(
|
|
&mut self,
|
|
indices: &mut IndexStore,
|
|
policies: &mut MachinePolicies,
|
|
code_repo: &CodeRepo,
|
|
prolog_stream: &mut PrologStream,
|
|
) {
|
|
let instr = match code_repo.lookup_instr(self.last_call, &self.p) {
|
|
Some(instr) => instr,
|
|
None => return,
|
|
};
|
|
|
|
self.dispatch_instr(instr.as_ref(), indices, policies, code_repo, prolog_stream);
|
|
}
|
|
|
|
fn backtrack(&mut self) {
|
|
if self.b > 0 {
|
|
let b = self.b;
|
|
|
|
self.b0 = self.stack.index_or_frame(b).prelude.b0;
|
|
self.p = CodePtr::Local(self.stack.index_or_frame(b).prelude.bp);
|
|
|
|
if let CodePtr::Local(LocalCodePtr::TopLevel(_, p)) = self.p {
|
|
self.fail = p == 0;
|
|
} else {
|
|
self.fail = false;
|
|
}
|
|
} else {
|
|
self.p = CodePtr::Local(LocalCodePtr::TopLevel(0, 0));
|
|
}
|
|
}
|
|
|
|
fn check_machine_index(&mut self, code_repo: &CodeRepo) -> bool {
|
|
match self.p {
|
|
CodePtr::Local(LocalCodePtr::DirEntry(p)) if p < code_repo.code.len() => {}
|
|
CodePtr::Local(LocalCodePtr::UserTermExpansion(p))
|
|
if p < code_repo.term_expanders.len() => {}
|
|
CodePtr::Local(LocalCodePtr::UserTermExpansion(_)) => self.fail = true,
|
|
CodePtr::Local(LocalCodePtr::UserGoalExpansion(p))
|
|
if p < code_repo.goal_expanders.len() => {}
|
|
CodePtr::Local(LocalCodePtr::UserGoalExpansion(_)) => self.fail = true,
|
|
CodePtr::Local(LocalCodePtr::InSituDirEntry(p)) if p < code_repo.in_situ_code.len() => {
|
|
}
|
|
CodePtr::Local(_) | CodePtr::REPL(..) => return false,
|
|
CodePtr::DynamicTransaction(..) => {
|
|
// prevent use of dynamic transactions from
|
|
// succeeding in expansions. self.fail will be toggled
|
|
// back to false later.
|
|
self.fail = true;
|
|
return false;
|
|
}
|
|
_ => {}
|
|
}
|
|
|
|
true
|
|
}
|
|
|
|
// return true iff verify_attr_interrupt is called.
|
|
fn verify_attr_stepper(
|
|
&mut self,
|
|
indices: &mut IndexStore,
|
|
policies: &mut MachinePolicies,
|
|
code_repo: &mut CodeRepo,
|
|
prolog_stream: &mut PrologStream,
|
|
) -> bool {
|
|
loop {
|
|
let instr = match code_repo.lookup_instr(self.last_call, &self.p) {
|
|
Some(instr) => {
|
|
if instr.as_ref().is_head_instr() {
|
|
instr
|
|
} else {
|
|
let cp = self.p.local();
|
|
self.run_verify_attr_interrupt(cp);
|
|
return true;
|
|
}
|
|
}
|
|
None => return false,
|
|
};
|
|
|
|
self.dispatch_instr(instr.as_ref(), indices, policies, code_repo, prolog_stream);
|
|
|
|
if self.fail {
|
|
self.backtrack();
|
|
}
|
|
|
|
if !self.check_machine_index(code_repo) {
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
fn run_verify_attr_interrupt(&mut self, cp: LocalCodePtr) {
|
|
let p = self.attr_var_init.verify_attrs_loc;
|
|
|
|
self.attr_var_init.cp = cp;
|
|
self.verify_attr_interrupt(p);
|
|
}
|
|
|
|
fn query_stepper(
|
|
&mut self,
|
|
indices: &mut IndexStore,
|
|
policies: &mut MachinePolicies,
|
|
code_repo: &mut CodeRepo,
|
|
prolog_stream: &mut PrologStream,
|
|
) {
|
|
loop {
|
|
self.execute_instr(indices, policies, code_repo, prolog_stream);
|
|
|
|
if self.fail {
|
|
self.backtrack();
|
|
}
|
|
|
|
match self.p {
|
|
CodePtr::VerifyAttrInterrupt(_) => {
|
|
self.p = CodePtr::Local(self.attr_var_init.cp);
|
|
|
|
let instigating_p = CodePtr::Local(self.attr_var_init.instigating_p);
|
|
let instigating_instr = code_repo.lookup_instr(false, &instigating_p).unwrap();
|
|
|
|
if !instigating_instr.as_ref().is_head_instr() {
|
|
let cp = self.p.local();
|
|
self.run_verify_attr_interrupt(cp);
|
|
} else if !self.verify_attr_stepper(indices, policies, code_repo, prolog_stream) {
|
|
if self.fail {
|
|
break;
|
|
}
|
|
|
|
let cp = self.p.local();
|
|
self.run_verify_attr_interrupt(cp);
|
|
}
|
|
}
|
|
_ => {
|
|
if !self.check_machine_index(code_repo) {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|