remove vestigial prolog/ directory (#444)

src/targets.rs

@@ -0,0 +1,175 @@
+use crate::prolog_parser::ast::*;
+
+use crate::clause_types::*;
+use crate::forms::*;
+use crate::instructions::*;
+use crate::iterators::*;
+
+pub trait CompilationTarget<'a> {
+    type Iterator: Iterator<Item = TermRef<'a>>;
+
+    fn iter(_: &'a Term) -> Self::Iterator;
+
+    fn to_constant(_: Level, _: Constant, _: RegType) -> Self;
+    fn to_list(_: Level, _: RegType) -> Self;
+    fn to_structure(_: ClauseType, _: usize, _: RegType) -> Self;
+
+    fn to_void(_: usize) -> Self;
+    fn is_void_instr(&self) -> bool;
+
+    fn to_pstr(lvl: Level, string: String, r: RegType, has_tail: bool) -> Self;
+
+    fn incr_void_instr(&mut self);
+
+    fn constant_subterm(_: Constant) -> Self;
+
+    fn argument_to_variable(_: RegType, _: usize) -> Self;
+    fn argument_to_value(_: RegType, _: usize) -> Self;
+
+    fn move_to_register(_: RegType, _: usize) -> Self;
+
+    fn subterm_to_variable(_: RegType) -> Self;
+    fn subterm_to_value(_: RegType) -> Self;
+
+    fn clause_arg_to_instr(_: RegType) -> Self;
+}
+
+impl<'a> CompilationTarget<'a> for FactInstruction {
+    type Iterator = FactIterator<'a>;
+
+    fn iter(term: &'a Term) -> Self::Iterator {
+        breadth_first_iter(term, false) // do not iterate over the root clause if one exists.
+    }
+
+    fn to_constant(lvl: Level, constant: Constant, reg: RegType) -> Self {
+        FactInstruction::GetConstant(lvl, constant, reg)
+    }
+
+    fn to_structure(ct: ClauseType, arity: usize, reg: RegType) -> Self {
+        FactInstruction::GetStructure(ct, arity, reg)
+    }
+
+    fn to_list(lvl: Level, reg: RegType) -> Self {
+        FactInstruction::GetList(lvl, reg)
+    }
+
+    fn to_void(subterms: usize) -> Self {
+        FactInstruction::UnifyVoid(subterms)
+    }
+
+    fn is_void_instr(&self) -> bool {
+        match self {
+            &FactInstruction::UnifyVoid(_) => true,
+            _ => false,
+        }
+    }
+
+    fn to_pstr(lvl: Level, string: String, r: RegType, has_tail: bool) -> Self {
+        FactInstruction::GetPartialString(lvl, string, r, has_tail)
+    }
+
+    fn incr_void_instr(&mut self) {
+        match self {
+            &mut FactInstruction::UnifyVoid(ref mut incr) => *incr += 1,
+            _ => {}
+        }
+    }
+
+    fn constant_subterm(constant: Constant) -> Self {
+        FactInstruction::UnifyConstant(constant)
+    }
+
+    fn argument_to_variable(arg: RegType, val: usize) -> Self {
+        FactInstruction::GetVariable(arg, val)
+    }
+
+    fn move_to_register(arg: RegType, val: usize) -> Self {
+        FactInstruction::GetVariable(arg, val)
+    }
+
+    fn argument_to_value(arg: RegType, val: usize) -> Self {
+        FactInstruction::GetValue(arg, val)
+    }
+
+    fn subterm_to_variable(val: RegType) -> Self {
+        FactInstruction::UnifyVariable(val)
+    }
+
+    fn subterm_to_value(val: RegType) -> Self {
+        FactInstruction::UnifyValue(val)
+    }
+
+    fn clause_arg_to_instr(val: RegType) -> Self {
+        FactInstruction::UnifyVariable(val)
+    }
+}
+
+impl<'a> CompilationTarget<'a> for QueryInstruction {
+    type Iterator = QueryIterator<'a>;
+
+    fn iter(term: &'a Term) -> Self::Iterator {
+        post_order_iter(term)
+    }
+
+    fn to_structure(ct: ClauseType, arity: usize, r: RegType) -> Self {
+        QueryInstruction::PutStructure(ct, arity, r)
+    }
+
+    fn to_constant(lvl: Level, constant: Constant, reg: RegType) -> Self {
+        QueryInstruction::PutConstant(lvl, constant, reg)
+    }
+
+    fn to_list(lvl: Level, reg: RegType) -> Self {
+        QueryInstruction::PutList(lvl, reg)
+    }
+
+    fn to_pstr(lvl: Level, string: String, r: RegType, has_tail: bool) -> Self {
+        QueryInstruction::PutPartialString(lvl, string, r, has_tail)
+    }
+
+    fn to_void(subterms: usize) -> Self {
+        QueryInstruction::SetVoid(subterms)
+    }
+
+    fn is_void_instr(&self) -> bool {
+        match self {
+            &QueryInstruction::SetVoid(_) => true,
+            _ => false,
+        }
+    }
+
+    fn incr_void_instr(&mut self) {
+        match self {
+            &mut QueryInstruction::SetVoid(ref mut incr) => *incr += 1,
+            _ => {}
+        }
+    }
+
+    fn constant_subterm(constant: Constant) -> Self {
+        QueryInstruction::SetConstant(constant)
+    }
+
+    fn argument_to_variable(arg: RegType, val: usize) -> Self {
+        QueryInstruction::PutVariable(arg, val)
+    }
+
+    fn move_to_register(arg: RegType, val: usize) -> Self {
+        QueryInstruction::GetVariable(arg, val)
+    }
+
+    fn argument_to_value(arg: RegType, val: usize) -> Self {
+        QueryInstruction::PutValue(arg, val)
+    }
+
+    fn subterm_to_variable(val: RegType) -> Self {
+        QueryInstruction::SetVariable(val)
+    }
+
+    fn subterm_to_value(val: RegType) -> Self {
+        QueryInstruction::SetValue(val)
+    }
+
+    fn clause_arg_to_instr(val: RegType) -> Self {
+        QueryInstruction::SetValue(val)
+    }
+}