finalize the module resolution operator.

diff --git a/README.md b/README.md
index 908a79cc5b848fc32cf973dfb663f8809b28b955..5629e7ae273df73704f8e29f30386b6ac169f5ed 100644 (file)
--- a/README.md
+++ b/README.md
@@ -108,6 +108,7 @@ The following predicates are built-in to rusty-wam.
     * `is/2` works for `(+)/2`, `(-)/{1,2}`, `(*)/2`, `(//)/2`, `(div)/2`, `(/)/2`, `(rdiv)/2`,
       `(xor)/2`, `(rem)/2`, `(mod)/2`, `(/\)/2`, `(\/)/2`, `(>>)/2`, `(<<)/2`.
     * Comparison operators: `>`, `<`, `=<`, `>=`, `=:=`, `=\=`.
+* `(:)/2`
 * `(@>)/2`
 * `(@>=)/2`
 * `(@=<)/2`
@@ -277,4 +278,13 @@ prolog> :- use_module(library(lists), [member/2]).
 ```
 
 A qualified `use_module` can be used to remove imports from the
-toplevel by calling it with an empty import list.
\ No newline at end of file
+toplevel by calling it with an empty import list.
+
+The `(:)/2` operator is used to resolve calls to predicates
+not within the current working namespace:
+
+```
+prolog> ?- lists:member(X, Xs).
+```
+
+This is a debugging kludge. Mostly.
\ No newline at end of file

diff --git a/src/prolog/ast.rs b/src/prolog/ast.rs
index 4ddaa2d037d3ce3934ec4eff759d3b773ad4ecdd..51b6cce71f7eeb64ed560ba47fdc625da091c27f 100644 (file)
--- a/src/prolog/ast.rs
+++ b/src/prolog/ast.rs
@@ -495,6 +495,7 @@ pub enum ParserError
     InvalidModuleExport,
     InvalidRuleHead,
     InvalidUseModuleDecl,
+    InvalidModuleResolution,
     MissingQuote,
     ParseBigInt,
     ParseFloat,
@@ -860,7 +861,7 @@ impl ClauseName {
             &ClauseName::User(ref name) => name.as_ref()
         }
     }
-
+    
     pub fn defrock_brackets(self) -> Self {
         fn defrock_brackets(s: &str) -> &str {
             if s.starts_with('(') && s.ends_with(')') {
@@ -1532,9 +1533,11 @@ impl HeapCellValue {
     }
 }
 
-#[derive(Clone, Copy, PartialEq)]
+#[derive(Clone, Copy,PartialEq)]
 pub enum IndexPtr {
-    Undefined, Index(usize)
+    Undefined, Index(usize),
+    Module // This is a resolved module call. The module
+    // targeted is in the wrapping CodeIndex, and the name is in the ClauseType.
 }
 
 #[derive(Clone)]
@@ -1542,7 +1545,7 @@ pub struct CodeIndex(pub Rc<RefCell<(IndexPtr, ClauseName)>>);
 
 impl CodeIndex {
     pub fn is_undefined(&self) -> bool {
-        let index_ptr = self.0.borrow().0;
+        let index_ptr = &self.0.borrow().0;
 
         if let IndexPtr::Undefined = index_ptr {
             true

diff --git a/src/prolog/compile.rs b/src/prolog/compile.rs
index 35b0c6971763ab615f6acc230205ef4745964fd6..d2906acbaf2496caa84ce5bb313ca01995a6ac68 100644 (file)
--- a/src/prolog/compile.rs
+++ b/src/prolog/compile.rs
@@ -38,10 +38,9 @@ fn print_code(code: &Code) {
 pub fn parse_code(wam: &mut Machine, buffer: &str) -> Result<TopLevelPacket, ParserError>
 {
     let atom_tbl = wam.atom_tbl();
-    let index = MachineCodeIndex {
+    let index = MachineCodeIndices {
         code_dir: &mut wam.code_dir,
         op_dir: &mut wam.op_dir,
-        //modules: &wam.modules
     };
 
     let mut worker = TopLevelWorker::new(buffer.as_bytes(), atom_tbl, index);
@@ -189,11 +188,11 @@ impl<'a> ListingCompiler<'a> {
         Ok(code)
     }
 
-    fn add_code(self, code: Code, indices: MachineCodeIndex) {
+    fn add_code(self, code: Code, indices: MachineCodeIndices) {
         let code_dir = mem::replace(indices.code_dir, HashMap::new());
         let op_dir   = mem::replace(indices.op_dir, HashMap::new());
 
-        if let Some(mut module) = self.module {            
+        if let Some(mut module) = self.module {
             module.code_dir.extend(as_module_code_dir(code_dir));
             module.op_dir.extend(op_dir.into_iter());
 
@@ -206,7 +205,7 @@ impl<'a> ListingCompiler<'a> {
 
 }
 
-fn use_module(module: &mut Option<Module>, submodule: &Module, indices: &mut MachineCodeIndex)
+fn use_module(module: &mut Option<Module>, submodule: &Module, indices: &mut MachineCodeIndices)
 {
     indices.use_module(submodule);
 
@@ -216,7 +215,7 @@ fn use_module(module: &mut Option<Module>, submodule: &Module, indices: &mut Mac
 }
 
 fn use_qualified_module(module: &mut Option<Module>, submodule: &Module, exports: &Vec<PredicateKey>,
-                        indices: &mut MachineCodeIndex)
+                        indices: &mut MachineCodeIndices)
 {
     indices.use_qualified_module(submodule, exports);
 
@@ -226,7 +225,7 @@ fn use_qualified_module(module: &mut Option<Module>, submodule: &Module, exports
 }
 
 pub
-fn compile_listing(wam: &mut Machine, src_str: &str, mut indices: MachineCodeIndex) -> EvalSession
+fn compile_listing(wam: &mut Machine, src_str: &str, mut indices: MachineCodeIndices) -> EvalSession
 {
     let mut worker   = TopLevelBatchWorker::new(src_str.as_bytes(), wam.atom_tbl());
     let mut compiler = ListingCompiler::new(wam);
@@ -264,12 +263,12 @@ fn compile_listing(wam: &mut Machine, src_str: &str, mut indices: MachineCodeInd
 }
 
 pub fn compile_user_module(wam: &mut Machine, src_str: &str) -> EvalSession {
-    let mut indices  = machine_code_index!(&mut CodeDir::new(), &mut default_op_dir());
+    let mut indices = machine_code_indices!(&mut CodeDir::new(), &mut default_op_dir());
 
     if let Some(ref builtins) = wam.modules.get(&clause_name!("builtins")) {
-        indices.use_module(builtins);        
+        indices.use_module(builtins);
     } else {
-        return EvalSession::from(SessionError::ModuleNotFound);        
+        return EvalSession::from(SessionError::ModuleNotFound);
     }
 
     compile_listing(wam, src_str, indices)

diff --git a/src/prolog/io.rs b/src/prolog/io.rs
index 5a55b0f1ddc2dba0641f3662c5a16514510f58b3..7f346b45f7247fa243f664600936cd6aed7477fb 100644 (file)
--- a/src/prolog/io.rs
+++ b/src/prolog/io.rs
@@ -12,8 +12,12 @@ use std::fmt;
 impl fmt::Display for IndexPtr {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match self {
-            &IndexPtr::Undefined => write!(f, "undefined"),
-            &IndexPtr::Index(i)  => write!(f, "{}", i)
+            &IndexPtr::Module =>
+                write!(f, ""),
+            &IndexPtr::Undefined =>
+                write!(f, "undefined"),
+            &IndexPtr::Index(i)  =>
+                write!(f, "{}", i)
         }
     }
 }

diff --git a/src/prolog/lib/builtins.pl b/src/prolog/lib/builtins.pl
index 35953a405109d8dab5957bb017f8cb4f8e3c3e05..94334f2ccda528419d8d40f52a6563036207a78d 100644 (file)
--- a/src/prolog/lib/builtins.pl
+++ b/src/prolog/lib/builtins.pl
@@ -5,7 +5,7 @@
        (>>)/2, (mod)/2, (rem)/2, (>)/2, (<)/2, (=\=)/2, (=:=)/2,
        (-)/1, (>=)/2, (=<)/2, (,)/2, (->)/2, (;)/2, (=..)/2, (==)/2,
        (\==)/2, (@=<)/2, (@>=)/2, (@<)/2, (@>)/2, (=@=)/2, (\=@=)/2,
-       catch/3, throw/1, true/0, false/0]).
+       (:)/2, catch/3, throw/1, true/0, false/0]).
 
 % arithmetic operators.
 :- op(700, xfx, is).
@@ -51,6 +51,9 @@
 :- op(700, xfx, =@=).
 :- op(700, xfx, \=@=).
 
+% module resolution operator.
+:- op(600, xfy, :).
+
 % the maximum arity flag. needs to be replaced with current_prolog_flag(max_arity, MAX_ARITY).
 max_arity(63).
 

diff --git a/src/prolog/machine/machine_errors.rs b/src/prolog/machine/machine_errors.rs
index a3cb86da14639a33b1cccd46e79b01de10aba00f..c23dd49bf136c5911ab2445ae0110cbec7dd2e33 100644 (file)
--- a/src/prolog/machine/machine_errors.rs
+++ b/src/prolog/machine/machine_errors.rs
@@ -35,6 +35,22 @@ impl MachineError {
         MachineError { stub, from: ErrorProvenance::Received }
     }
 
+    pub(super)
+    fn module_resolution_error(h: usize, mod_name: ClauseName, name: ClauseName, arity: usize) -> Self
+    {
+        let mod_name = HeapCellValue::Addr(Addr::Con(Constant::Atom(mod_name)));
+        let name = HeapCellValue::Addr(Addr::Con(Constant::Atom(name)));
+        
+        let mut stub = functor!("evaluation_error", 1, [HeapCellValue::Addr(Addr::HeapCell(h + 2))]);
+        
+        stub.append(&mut functor!("/", 2, [HeapCellValue::Addr(Addr::HeapCell(h + 2 + 3)),
+                                           heap_integer!(arity)],
+                                  Fixity::In));
+        stub.append(&mut functor!(":", 2, [mod_name, name], Fixity::In));
+
+        MachineError { stub, from: ErrorProvenance::Constructed }
+    }
+    
     pub(super) fn existence_error(h: usize, name: ClauseName, arity: usize) -> Self {
         let mut stub = functor!("existence_error", 2, [heap_atom!("procedure"), heap_str!(3 + h)]);
         stub.append(&mut Self::functor_stub(name, arity));

diff --git a/src/prolog/machine/machine_state.rs b/src/prolog/machine/machine_state.rs
index 5ccf181c752d6bada2737a199179c4d579a6dc65..8e1a9a0449dd5aaaa8a9cb7fe12414233d385733 100644 (file)
--- a/src/prolog/machine/machine_state.rs
+++ b/src/prolog/machine/machine_state.rs
@@ -33,7 +33,7 @@ impl Ball {
 
 pub(crate) struct CodeDirs<'a> {
     code_dir: &'a CodeDir,
-    modules: &'a HashMap<ClauseName, Module>
+    modules: &'a ModuleDir
 }
 
 impl<'a> CodeDirs<'a> {
@@ -225,6 +225,21 @@ pub struct MachineState {
     pub(super) last_call: bool
 }
 
+fn call_at_index(machine_st: &mut MachineState, module_name: ClauseName, arity: usize, idx: usize)
+{
+    machine_st.cp.assign_if_local(machine_st.p.clone() + 1);
+    machine_st.num_of_args = arity;
+    machine_st.b0 = machine_st.b;
+    machine_st.p  = dir_entry!(idx, module_name);
+}
+
+fn execute_at_index(machine_st: &mut MachineState, module_name: ClauseName, arity: usize, idx: usize)
+{
+    machine_st.num_of_args = arity;
+    machine_st.b0 = machine_st.b;
+    machine_st.p  = dir_entry!(idx, module_name);
+}
+
 pub(crate) type CallResult = Result<(), Vec<HeapCellValue>>;
 
 pub(crate) trait CallPolicy: Any {
@@ -352,35 +367,46 @@ pub(crate) trait CallPolicy: Any {
     }
 
     fn context_call(&mut self, machine_st: &mut MachineState, name: ClauseName, arity: usize,
-                    idx: CodeIndex)
+                    idx: CodeIndex, code_dirs: CodeDirs)
                     -> CallResult
     {
         if machine_st.last_call {
-            self.try_execute(machine_st, name, arity, idx)
+            self.try_execute(machine_st, name, arity, idx, code_dirs)
         } else {
-            self.try_call(machine_st, name, arity, idx)
+            self.try_call(machine_st, name, arity, idx, code_dirs)
         }
     }
 
-    fn try_call(&mut self, machine_st: &mut MachineState, name: ClauseName,
-                arity: usize, idx: CodeIndex)
+    fn try_call(&mut self, machine_st: &mut MachineState, name: ClauseName, arity: usize,
+                idx: CodeIndex, code_dirs: CodeDirs)
                 -> CallResult
-    {                
+    {
         match idx.0.borrow().0 {
+            IndexPtr::Module => {
+                let stub = MachineError::functor_stub(name.clone(), arity);
+                let module_name = idx.0.borrow().1.clone();
+                let h = machine_st.heap.h;
+
+                if let Some(ref idx) = code_dirs.get(name.clone(), arity, module_name.clone()) {
+                    if let IndexPtr::Index(compiled_tl_index) = idx.0.borrow().0 {
+                        call_at_index(machine_st, module_name, arity, compiled_tl_index);
+                        return Ok(());
+                    }
+                }
+
+                let err = MachineError::module_resolution_error(h, module_name, name, arity);
+                return Err(machine_st.error_form(err, stub));
+            },
             IndexPtr::Undefined => {
                 let stub = MachineError::functor_stub(name.clone(), arity);
                 let h = machine_st.heap.h;
-                
+
                 return Err(machine_st.error_form(MachineError::existence_error(h, name, arity),
                                                  stub));
             },
             IndexPtr::Index(compiled_tl_index) => {
                 let module_name = idx.0.borrow().1.clone();
-
-                machine_st.cp.assign_if_local(machine_st.p.clone() + 1);
-                machine_st.num_of_args = arity;
-                machine_st.b0 = machine_st.b;
-                machine_st.p  = dir_entry!(compiled_tl_index, module_name);
+                call_at_index(machine_st, module_name, arity, compiled_tl_index)
             }
         }
 
@@ -388,23 +414,35 @@ pub(crate) trait CallPolicy: Any {
     }
 
     fn try_execute<'a>(&mut self, machine_st: &mut MachineState, name: ClauseName,
-                       arity: usize, idx: CodeIndex)
+                       arity: usize, idx: CodeIndex, code_dirs: CodeDirs)
                        -> CallResult
     {
         match idx.0.borrow().0 {
+            IndexPtr::Module => {
+                let stub = MachineError::functor_stub(name.clone(), arity);
+                let module_name = idx.0.borrow().1.clone();
+                let h = machine_st.heap.h;
+
+                if let Some(ref idx) = code_dirs.get(name.clone(), arity, module_name.clone()) {
+                    if let IndexPtr::Index(compiled_tl_index) = idx.0.borrow().0 {
+                        execute_at_index(machine_st, module_name, arity, compiled_tl_index);
+                        return Ok(());
+                    }
+                }
+
+                let err = MachineError::module_resolution_error(h, module_name, name, arity);
+                return Err(machine_st.error_form(err, stub));
+            },
             IndexPtr::Undefined => {
                 let stub = MachineError::functor_stub(name.clone(), arity);
                 let h = machine_st.heap.h;
-                
+
                 return Err(machine_st.error_form(MachineError::existence_error(h, name, arity),
                                                  stub));
             },
             IndexPtr::Index(compiled_tl_index) => {
                 let module_name = idx.0.borrow().1.clone();
-
-                machine_st.num_of_args = arity;
-                machine_st.b0 = machine_st.b;
-                machine_st.p  = dir_entry!(compiled_tl_index, module_name);
+                execute_at_index(machine_st, module_name, arity, compiled_tl_index);
             }
         }
 
@@ -552,7 +590,7 @@ pub(crate) trait CallPolicy: Any {
                     machine_st.execute_inlined(&inlined),
                 ClauseType::Op(..) | ClauseType::Named(..) =>
                     if let Some(idx) = code_dirs.get(name.clone(), arity, user) {
-                        self.context_call(machine_st, name, arity, idx)?;
+                        self.context_call(machine_st, name, arity, idx, code_dirs)?;
                     } else {
                         let h = machine_st.heap.h;
                         let stub = MachineError::functor_stub(clause_name!("call"), arity + 1);
@@ -562,7 +600,7 @@ pub(crate) trait CallPolicy: Any {
                 ClauseType::System(_) => {
                     let name = Addr::Con(Constant::Atom(name));
                     let stub = MachineError::functor_stub(clause_name!("call"), arity + 1);
-                    
+
                     return Err(machine_st.error_form(MachineError::type_error(ValidType::Callable,
                                                                               name),
                                                      stub));
@@ -576,10 +614,10 @@ pub(crate) trait CallPolicy: Any {
 
 impl CallPolicy for CallWithInferenceLimitCallPolicy {
     fn context_call(&mut self, machine_st: &mut MachineState, name: ClauseName,
-                    arity: usize, idx: CodeIndex)
+                    arity: usize, idx: CodeIndex, code_dirs: CodeDirs)
                     -> CallResult
     {
-        self.prev_policy.context_call(machine_st, name, arity, idx)?;
+        self.prev_policy.context_call(machine_st, name, arity, idx, code_dirs)?;
         self.increment()
     }
 
@@ -747,7 +785,7 @@ impl CutPolicy for SCCCutPolicy {
         let b = machine_st.b;
 
         if let Addr::Con(Constant::Usize(b0)) = machine_st[r].clone() {
-            if b > b0 {                
+            if b > b0 {
                 machine_st.b = b0;
                 machine_st.tidy_trail();
                 machine_st.or_stack.truncate(machine_st.b);
@@ -755,8 +793,8 @@ impl CutPolicy for SCCCutPolicy {
         } else {
             machine_st.fail = true;
             return;
-        }    
-        
+        }
+
         if let Some(&(_, b_cutoff, prev_block)) = self.cont_pts.last() {
             if machine_st.b < b_cutoff {
                 machine_st.block = prev_block;

diff --git a/src/prolog/machine/machine_state_impl.rs b/src/prolog/machine/machine_state_impl.rs
index 984d1dc254972190c9c24f3e94f5c4a0c1471ecf..2ee034c0e791a4ddac110f1899b14ca48b4cc57b 100644 (file)
--- a/src/prolog/machine/machine_state_impl.rs
+++ b/src/prolog/machine/machine_state_impl.rs
@@ -1832,7 +1832,8 @@ impl MachineState {
             &ControlInstruction::CallClause(ClauseType::Named(ref name, ref idx), arity, _, lco)
           | &ControlInstruction::CallClause(ClauseType::Op(ref name, _, ref idx), arity, _, lco) => {
                 self.last_call = lco;
-                try_or_fail!(self, call_policy.context_call(self, name.clone(), arity, idx.clone()));
+                try_or_fail!(self, call_policy.context_call(self, name.clone(), arity, idx.clone(),
+                                                            code_dirs));
             },
             &ControlInstruction::CallClause(ClauseType::System(ref ct), _, _, lco) => {
                 self.last_call = lco;

diff --git a/src/prolog/machine/mod.rs b/src/prolog/machine/mod.rs
index e42981f037e1cb1dc8faacf1d56e92f0b2d11ce4..dc3bdd1962f3a863566082d054c2ffceb0581156 100644 (file)
--- a/src/prolog/machine/mod.rs
+++ b/src/prolog/machine/mod.rs
@@ -17,13 +17,12 @@ use std::mem::swap;
 use std::ops::Index;
 use std::rc::Rc;
 
-pub struct MachineCodeIndex<'a> {
-    pub code_dir: &'a mut CodeDir,
-    pub op_dir: &'a mut OpDir,
-//    pub modules: &'a ModuleDir
+pub struct MachineCodeIndices<'a> {
+    pub(super) code_dir: &'a mut CodeDir,
+    pub(super) op_dir: &'a mut OpDir,
 }
 
-impl<'a> MachineCodeIndex<'a> {
+impl<'a> MachineCodeIndices<'a> {
     pub(super)
     fn lookup(&mut self, name: ClauseName, arity: usize, fixity: Option<Fixity>) -> ClauseType
     {
@@ -73,7 +72,7 @@ impl Index<LocalCodePtr> for Machine {
     }
 }
 
-impl<'a> SubModuleUser for MachineCodeIndex<'a> {
+impl<'a> SubModuleUser for MachineCodeIndices<'a> {
     fn op_dir(&mut self) -> &mut OpDir {
         self.op_dir
     }
@@ -111,7 +110,7 @@ impl Machine {
             cached_query: None
         };
 
-        let indices = machine_code_index!(&mut CodeDir::new(), &mut default_op_dir());
+        let indices = machine_code_indices!(&mut CodeDir::new(), &mut default_op_dir());
         compile_listing(&mut wam, BUILTINS, indices);
 
         compile_user_module(&mut wam, LISTS);
@@ -178,14 +177,14 @@ impl Machine {
         self.ms.atom_tbl.clone()
     }
 
-    pub fn use_qualified_module_in_toplevel(&mut self, name: ClauseName, exports: Vec<PredicateKey>) -> EvalSession
+    pub fn use_qualified_module_in_toplevel(&mut self, name: ClauseName, exports: Vec<PredicateKey>)
+                                            -> EvalSession
     {
         self.remove_module(name.clone());
 
         if let Some(mut module) = self.modules.remove(&name) {
             let result = {
-                let mut indices = machine_code_index!(&mut self.code_dir, &mut self.op_dir);
-                                                      //&self.modules);
+                let mut indices = machine_code_indices!(&mut self.code_dir, &mut self.op_dir);
                 indices.use_qualified_module(&mut module, &exports)
             };
 
@@ -202,8 +201,7 @@ impl Machine {
 
         if let Some(mut module) = self.modules.remove(&name) {
             let result = {
-                let mut indices = machine_code_index!(&mut self.code_dir, &mut self.op_dir);
-                                                      //&self.modules);
+                let mut indices = machine_code_indices!(&mut self.code_dir, &mut self.op_dir);
                 indices.use_module(&mut module)
             };
 

diff --git a/src/prolog/macros.rs b/src/prolog/macros.rs
index f3bb0d5009a4a5533773a173d2d240c1cf62ef8e..fc287fc7066d9cb713691f17f2952f6c22ccbd72 100644 (file)
--- a/src/prolog/macros.rs
+++ b/src/prolog/macros.rs
@@ -233,9 +233,9 @@ macro_rules! set_code_index {
     }}
 }
 
-macro_rules! machine_code_index {
+macro_rules! machine_code_indices {
     ($code_dir:expr, $op_dir:expr) => ( //, $modules:expr) => (
-        MachineCodeIndex { code_dir: $code_dir, op_dir: $op_dir } //, modules: $modules }
+        MachineCodeIndices { code_dir: $code_dir, op_dir: $op_dir } //, modules: $modules }
     )
 }
 

diff --git a/src/prolog/parser b/src/prolog/parser
index 25b422477921de898dd50b0aa33be8fac5a0ec61..a7b81b591bce10f93a5f835336c588be763516c6 160000 (submodule)
--- a/src/prolog/parser
+++ b/src/prolog/parser
@@ -1 +1 @@
-Subproject commit 25b422477921de898dd50b0aa33be8fac5a0ec61
+Subproject commit a7b81b591bce10f93a5f835336c588be763516c6

diff --git a/src/prolog/toplevel.rs b/src/prolog/toplevel.rs
index 3fac73ca1d4f36272d5e02a380e3680c0c0c379c..2c82ea56e1d6ad015b5ea847f4b24f2674157b4c 100644 (file)
--- a/src/prolog/toplevel.rs
+++ b/src/prolog/toplevel.rs
@@ -5,7 +5,7 @@ use prolog::parser::parser::*;
 use prolog::tabled_rc::*;
 
 use std::collections::{HashSet, VecDeque};
-use std::cell::Cell;
+use std::cell::{Cell, RefCell};
 use std::io::Read;
 use std::mem;
 use std::rc::Rc;
@@ -288,6 +288,17 @@ fn mark_cut_variables(terms: &mut Vec<Term>) -> bool {
     found_cut_var
 }
 
+fn module_resolution_call(mod_name: Term, body: Term) -> Result<QueryTerm, ParserError> {
+    if let Term::Constant(_, Constant::Atom(mod_name)) = mod_name {
+        if let Term::Clause(_, name, terms, _) = body {
+            let idx = CodeIndex(Rc::new(RefCell::new((IndexPtr::Module, mod_name))));
+            return Ok(QueryTerm::Clause(Cell::default(), ClauseType::Named(name, idx), terms));
+        }
+    }
+
+    Err(ParserError::InvalidModuleResolution)
+}
+
 pub enum TopLevelPacket {
     Query(Vec<QueryTerm>, Vec<TopLevel>),
     Decl(TopLevel, Vec<TopLevel>)
@@ -391,7 +402,7 @@ impl RelationWorker {
         self.fabricate_rule(fold_by_str(prec_seq, body_term, comma_sym))
     }
 
-    fn to_query_term(&mut self, indices: &mut MachineCodeIndex, term: Term)
+    fn to_query_term(&mut self, indices: &mut MachineCodeIndices, term: Term)
                      -> Result<QueryTerm, ParserError>
     {
         match term {
@@ -411,6 +422,11 @@ impl RelationWorker {
 
                     self.queue.push_back(clauses);
                     Ok(QueryTerm::Jump(stub))
+                } else if name.as_str() == ":" && terms.len() == 2 {
+                    let callee   = *terms.pop().unwrap();
+                    let mod_name = *terms.pop().unwrap();
+                    
+                    module_resolution_call(mod_name, callee)
                 } else if name.as_str() == "->" && terms.len() == 2 {
                     let conq = *terms.pop().unwrap();
                     let prec = *terms.pop().unwrap();
@@ -460,7 +476,7 @@ impl RelationWorker {
         }
     }
 
-    fn setup_query(&mut self, idx: &mut MachineCodeIndex, terms: Vec<Box<Term>>, blocks_cuts: bool)
+    fn setup_query(&mut self, idx: &mut MachineCodeIndices, terms: Vec<Box<Term>>, blocks_cuts: bool)
                    -> Result<Vec<QueryTerm>, ParserError>
     {
         let mut query_terms = vec![];
@@ -495,7 +511,7 @@ impl RelationWorker {
         Ok(query_terms)
     }
 
-    fn setup_rule(&mut self, idx: &mut MachineCodeIndex, mut terms: Vec<Box<Term>>, blocks_cuts: bool)
+    fn setup_rule(&mut self, idx: &mut MachineCodeIndices, mut terms: Vec<Box<Term>>, blocks_cuts: bool)
                   -> Result<Rule, ParserError>
     {
         let post_head_terms = terms.drain(1..).collect();
@@ -512,7 +528,7 @@ impl RelationWorker {
         }
     }
 
-    fn try_term_to_tl(&mut self, idx: &mut MachineCodeIndex, term: Term, blocks_cuts: bool)
+    fn try_term_to_tl(&mut self, idx: &mut MachineCodeIndices, term: Term, blocks_cuts: bool)
                       -> Result<TopLevel, ParserError>
     {
         match term {
@@ -531,7 +547,7 @@ impl RelationWorker {
         }
     }
 
-    fn try_terms_to_tls<Iter>(&mut self, idx: &mut MachineCodeIndex, terms: Iter, blocks_cuts: bool)
+    fn try_terms_to_tls<Iter>(&mut self, idx: &mut MachineCodeIndices, terms: Iter, blocks_cuts: bool)
                               -> Result<VecDeque<TopLevel>, ParserError>
         where Iter: IntoIterator<Item=Term>
     {
@@ -544,7 +560,7 @@ impl RelationWorker {
         Ok(results)
     }
 
-    fn parse_queue(&mut self, idx: &mut MachineCodeIndex) -> Result<VecDeque<TopLevel>, ParserError>
+    fn parse_queue(&mut self, idx: &mut MachineCodeIndices) -> Result<VecDeque<TopLevel>, ParserError>
     {
         let mut queue = VecDeque::new();
 
@@ -563,11 +579,11 @@ impl RelationWorker {
 
 pub struct TopLevelWorker<'a, R: Read> {
     pub parser: Parser<R>,
-    indices: MachineCodeIndex<'a>
+    indices: MachineCodeIndices<'a>
 }
 
 impl<'a, R: Read> TopLevelWorker<'a, R> {
-    pub fn new(inner: R, atom_tbl: TabledData<Atom>, indices: MachineCodeIndex<'a>) -> Self {
+    pub fn new(inner: R, atom_tbl: TabledData<Atom>, indices: MachineCodeIndices<'a>) -> Self {
         TopLevelWorker { parser: Parser::new(inner, atom_tbl), indices }
     }
 
@@ -612,7 +628,7 @@ impl<R: Read> TopLevelBatchWorker<R> {
     }
 
     pub
-    fn consume(&mut self, indices: &mut MachineCodeIndex) -> Result<Option<Declaration>, SessionError>
+    fn consume(&mut self, indices: &mut MachineCodeIndices) -> Result<Option<Declaration>, SessionError>
     {
         let mut preds = vec![];