From f9448e894e6db7093d4c892649c3df7f4c0a3095 Mon Sep 17 00:00:00 2001
From: Mark Thom <markjordanthom@gmail.com>
Date: Mon, 22 Apr 2019 19:48:09 -0600
Subject: [PATCH] use binary_pow for (^)/2

---
 Cargo.toml                               |  2 +-
 src/prolog/machine/compile.rs            |  2 ++
 src/prolog/machine/machine_errors.rs     |  2 --
 src/prolog/machine/machine_state_impl.rs | 20 +++++++++++++++++---
 4 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 5c096128..89d699e7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,7 +14,7 @@ cfg-if = "0.1.7"
 downcast = "0.10.0"
 num = "0.2"
 ordered-float = "0.5.0"
-prolog_parser = "0.8.20"
+prolog_parser = "0.8.21"
 readline_rs_compat = { version = "0.1.9", optional = true }
 ref_thread_local = "0.0.0"
 
diff --git a/src/prolog/machine/compile.rs b/src/prolog/machine/compile.rs
index ac60200a..919d7b82 100644
--- a/src/prolog/machine/compile.rs
+++ b/src/prolog/machine/compile.rs
@@ -123,6 +123,8 @@ fn compile_query(terms: Vec<QueryTerm>, queue: VecDeque<TopLevel>, flags: Machin
     let mut code = try!(cg.compile_query(&terms));
 
     compile_appendix(&mut code, &queue, false, flags)?;
+
+    print_code(&code);
     Ok((code, cg.take_vars()))
 }
 
diff --git a/src/prolog/machine/machine_errors.rs b/src/prolog/machine/machine_errors.rs
index ddff619f..bdfdd343 100644
--- a/src/prolog/machine/machine_errors.rs
+++ b/src/prolog/machine/machine_errors.rs
@@ -249,7 +249,6 @@ impl RepFlag {
 #[derive(Clone, Copy)]
 pub enum EvalError {
 //    FloatOverflow,
-//    IntOverflow,
 //    Undefined,
 //    FloatUnderflow,
     ZeroDivisor,
@@ -260,7 +259,6 @@ impl EvalError {
     pub fn as_str(self) -> &'static str {
         match self {
 //            EvalError::FloatOverflow => "float_overflow",
-//            EvalError::IntOverflow => "int_overflow",
 //            EvalError::Undefined => "undefined",
 //            EvalError::FloatUnderflow => "underflow",
             EvalError::ZeroDivisor => "zero_divisor",
diff --git a/src/prolog/machine/machine_state_impl.rs b/src/prolog/machine/machine_state_impl.rs
index 516dccc6..736e7440 100644
--- a/src/prolog/machine/machine_state_impl.rs
+++ b/src/prolog/machine/machine_state_impl.rs
@@ -721,7 +721,7 @@ impl MachineState {
         let caller = MachineError::functor_stub(clause_name!("(is)"), 2);
         let mut interms: Vec<Number> = Vec::with_capacity(64);
 
-        for heap_val in self.post_order_iter(a) {
+        for heap_val in self.heap.post_order_iter(a) {
             match heap_val {
                 HeapCellValue::NamedStr(2, name, _) => {
                     let a2 = interms.pop().unwrap();
@@ -733,7 +733,7 @@ impl MachineState {
                         "*" => interms.push(a1 * a2),
                         "/" => interms.push(self.div(a1, a2)?),
                         "**" => interms.push(self.pow(a1, a2)?),
-                        "^"  => interms.push(self.pow(a1, a2)?),
+                        "^"  => interms.push(self.binary_pow(a1, a2)?),
                         "max"  => interms.push(self.max(a1, a2)?),
                         "rdiv" => {
                             let r1 = self.get_rational(&ArithmeticTerm::Number(a1), &caller)?;
@@ -841,6 +841,20 @@ impl MachineState {
         }
     }
 
+    fn binary_pow(&self, n1: Number, n2: Number) -> Result<Number, MachineStub>
+    {
+        match (n1, n2) {
+            (Number::Integer(n1), Number::Integer(n2)) =>
+                self.pow(Number::Integer(n1), Number::Integer(n2)),
+            (Number::Integer(_), n) | (n, _) => {
+                let n = Addr::Con(Constant::Number(n));
+                let stub = MachineError::functor_stub(clause_name!("^"), 2);
+                
+                Err(self.error_form(MachineError::type_error(ValidType::Integer, n), stub))                
+            }
+        }
+    }
+    
     fn pow(&self, n1: Number, n2: Number) -> Result<Number, MachineStub>
     {
         match n1.pow(n2) {
@@ -1033,7 +1047,7 @@ impl MachineState {
                 let n1 = try_or_fail!(self, self.get_number(a1));
                 let n2 = try_or_fail!(self, self.get_number(a2));
 
-                self.interms[t - 1] = try_or_fail!(self, self.pow(n1, n2));
+                self.interms[t - 1] = try_or_fail!(self, self.binary_pow(n1, n2));
                 self.p += 1;
             },
             &ArithmeticInstruction::Pow(ref a1, ref a2, t) => {
-- 
2.54.0