From: Mark Thom <markjordanthom@gmail.com>
Date: Mon, 4 May 2020 02:31:12 +0000 (-0600)
Subject: use select/3 in gather_equations for detecting whether variables are distinct.
X-Git-Tag: v0.8.123~62
X-Git-Url: https://git.sagredo.dev/?a=commitdiff_plain;h=e5903d8d6eee8da6924334f1d6aad2a8f80d1097;p=scryer-prolog.git

use select/3 in gather_equations for detecting whether variables are distinct.
---

diff --git a/src/prolog/machine/compile.rs b/src/prolog/machine/compile.rs
index 10bc4d22..64f56a30 100644
--- a/src/prolog/machine/compile.rs
+++ b/src/prolog/machine/compile.rs
@@ -763,14 +763,14 @@ impl ListingCompiler {
     }
 
     fn generate_init_goal_code(
-	&mut self,
+	    &mut self,
     ) -> Result<Code, SessionError> {
-	let query_terms = mem::replace(&mut self.initialization_goals.0, vec![]);
-	let queue = mem::replace(&mut self.initialization_goals.1, VecDeque::new());
+	    let query_terms = mem::replace(&mut self.initialization_goals.0, vec![]);
+	    let queue = mem::replace(&mut self.initialization_goals.1, VecDeque::new());
 
-	compile_query(query_terms, queue)
-	    .map(|(code, _)| code)
-	    .map_err(SessionError::from)
+	    compile_query(query_terms, queue)
+	        .map(|(code, _)| code)
+	        .map_err(SessionError::from)
     }
 
     fn set_code_index(
@@ -1143,7 +1143,8 @@ impl ListingCompiler {
         result
     }
 
-    pub(crate) fn gather_items(
+    pub(crate)
+    fn gather_items(
         &mut self,
         wam: &mut Machine,
         src: &mut ParsingStream<Stream>,
@@ -1339,7 +1340,7 @@ fn compile_work_impl(
     let init_goal_code = compiler.generate_init_goal_code()?;
 
     if init_goal_code.len() > 0 {
-	if !wam.run_init_code(init_goal_code) {
+	    if !wam.run_init_code(init_goal_code) {
             println!("Warning: initialization goal for {} failed",
                      compiler.listing_src.name());
         }
diff --git a/src/prolog/toplevel.pl b/src/prolog/toplevel.pl
index a939a40d..ed17f80a 100644
--- a/src/prolog/toplevel.pl
+++ b/src/prolog/toplevel.pl
@@ -235,7 +235,7 @@ write_eqs_and_read_input(B, VarList) :-
     append([Vars0, AttrVars, AttrGoalVars], Vars),
     charsio:extend_var_list(Vars, VarList, NewVarList, fabricated),
     '$get_b_value'(B0),
-    gather_equations(NewVarList, Goals, AttrGoals),
+    gather_equations(NewVarList, NewVarList, Goals, AttrGoals),
     (   bb_get('$first_answer', true) ->
         write('   '),
         bb_put('$first_answer', false)
@@ -294,17 +294,18 @@ gather_query_vars([], []).
 
 is_a_different_variable([_ = Binding | Pairs], Value) :-
     (  Value == Binding, !
-    ;  is_a_different_variable(Pairs, Value)
+    ;  is_a_different_variable(Pairs, Var)
     ).
 
-gather_equations([], Goals, Goals).
-gather_equations([Var = Value | Pairs], Goals, Goals1) :-
+gather_equations([], MasterList, Goals, Goals).
+gather_equations([Var = Value | Pairs], MasterList, Goals, Goals1) :-
+    select((Var = _), MasterList, MasterPairs),
     (  (  nonvar(Value)
-       ;  is_a_different_variable(Pairs, Value)
+       ;  is_a_different_variable(MasterPairs, Value)
        ) ->
        Goals = [Var = Value | Goals0],
-       gather_equations(Pairs, Goals0, Goals1)
-    ;  gather_equations(Pairs, Goals, Goals1)
+       gather_equations(Pairs, MasterList, Goals0, Goals1)
+    ;  gather_equations(Pairs, MasterList, Goals, Goals1)
     ).
 
 print_exception(E) :-