From f9397f8caca632b1a71ca837708ee92e04d47ccf Mon Sep 17 00:00:00 2001
From: Adrien Burgun <adrien.burgun@orange.fr>
Date: Mon, 9 Oct 2023 16:47:57 +0200
Subject: [PATCH] :sparkles: NOT operator and UnaryOperator DCE

---
 GUIDE.md                     | 24 ++++++++++++++++++------
 examples/reactor-safety.mbas | 11 +++++++++++
 src/optimize/dead.rs         |  4 +++-
 src/optimize/jump.rs         |  5 +++++
 src/repr/operator.rs         | 13 ++-----------
 src/translate/display.rs     | 12 ++++++++++++
 6 files changed, 51 insertions(+), 18 deletions(-)
 create mode 100644 examples/reactor-safety.mbas

diff --git a/GUIDE.md b/GUIDE.md
index 0d2a465..38bd08b 100644
--- a/GUIDE.md
+++ b/GUIDE.md
@@ -243,13 +243,25 @@ The "return stack" is cleared at the beginning of the generated program.
 
 `mlog` provides several ways for processors to interact with the in-game world, which are reflected in MinBasic using functions:
 
-<!-- ### `sensor`
+### Sensor, Control and Set Prop
 
-The `sensor` instruction becomes the `.` operator:
+The easiest way to read data from units or blocks, and to write data to those, is to use the dot (`.`) operator:
 
 ```basic
-health = SENSOR(@unit, @health)
-health = @unit.health
+REM A simple program to shut down reactors when their health of cryofluid amount dips too low
+LET reactor = reactor1
 
-@unit.health = @unit.health - 10
-``` -->
+LET enoughHealth = reactor.health >= reactor.maxHealth / 2
+LET enoughCryofluid = reactor.cryofluid >= reactor.liquidCapacity
+
+IF NOT(enoughHealth AND enoughCryofluid) THEN
+    reactor.enabled = false
+ELSE
+    reactor.enabled = true
+END IF
+```
+
+When reading, the dot operator translates to the `sensor` instruction, and replaces the key with its corresponding `@`-variable (`block1.health` becomes `sensor @health block1`, `@unit.x` becomes `sensor @x @unit`, etc.)
+
+When writing, the `control` instruction is used when possible, namely with `.enabled`, `.config` and `.color`.
+Otherwise, the `setprop` instruction is used, which is only available to world processors, and the key is replaced with its corresponding `@`-variable.
diff --git a/examples/reactor-safety.mbas b/examples/reactor-safety.mbas
new file mode 100644
index 0000000..8852dc9
--- /dev/null
+++ b/examples/reactor-safety.mbas
@@ -0,0 +1,11 @@
+REM A simple program to shut down reactors when their health of cryofluid amount dips too low
+LET reactor = reactor1
+
+LET enoughHealth = reactor.health >= reactor.maxHealth / 2
+LET enoughCryofluid = reactor.cryofluid >= reactor.liquidCapacity
+
+IF NOT(enoughHealth AND enoughCryofluid) THEN
+    reactor.enabled = false
+ELSE
+    reactor.enabled = true
+END IF
diff --git a/src/optimize/dead.rs b/src/optimize/dead.rs
index ca8e742..3277708 100644
--- a/src/optimize/dead.rs
+++ b/src/optimize/dead.rs
@@ -31,7 +31,9 @@ pub(crate) fn optimize_dead_code(program: MindustryProgram) -> MindustryProgram
     replace_if(
         program,
         |_instructions, instruction, _index| match instruction {
-            MindustryOperation::Set(name, _) | MindustryOperation::Operator(name, _, _, _) => {
+            MindustryOperation::Set(name, _)
+            | MindustryOperation::Operator(name, _, _, _)
+            | MindustryOperation::UnaryOperator(name, _, _) => {
                 if !is_temporary_variable(name) {
                     return None;
                 }
diff --git a/src/optimize/jump.rs b/src/optimize/jump.rs
index 10dc70e..8c1f5b7 100644
--- a/src/optimize/jump.rs
+++ b/src/optimize/jump.rs
@@ -48,6 +48,11 @@ pub fn optimize_jump_op(program: MindustryProgram) -> MindustryProgram {
                             {
                                 Lookaround::Stop((*operator, lhs.clone(), rhs.clone()))
                             }
+                            MindustryOperation::UnaryOperator(name, operator, value)
+                                if *name == var_name && *operator == UnaryOperator::Not =>
+                            {
+                                Lookaround::Stop((Operator::Eq, value.clone(), Operand::Integer(0)))
+                            }
                             x if x.mutates(&var_name) || x.breaks_flow() => Lookaround::Abort,
                             _ => Lookaround::Continue,
                         },
diff --git a/src/repr/operator.rs b/src/repr/operator.rs
index 7da5aed..9290f73 100644
--- a/src/repr/operator.rs
+++ b/src/repr/operator.rs
@@ -108,7 +108,7 @@ pub enum UnaryOperator {
     Ceil,
     Rand,
     Sqrt,
-    // Not,
+    Not,
 }
 
 impl TryFrom<&str> for UnaryOperator {
@@ -121,17 +121,8 @@ impl TryFrom<&str> for UnaryOperator {
             "ceil" => Ok(Self::Ceil),
             "rand" => Ok(Self::Rand),
             "sqrt" => Ok(Self::Sqrt),
+            "not" => Ok(Self::Not),
             _ => Err(()),
         }
     }
 }
-
-pub(crate) fn format_unary_operator(operator: UnaryOperator) -> &'static str {
-    match operator {
-        UnaryOperator::Floor => "floor",
-        UnaryOperator::Round => "round",
-        UnaryOperator::Ceil => "ceil",
-        UnaryOperator::Rand => "rand",
-        UnaryOperator::Sqrt => "sqrt",
-    }
-}
diff --git a/src/translate/display.rs b/src/translate/display.rs
index 7baadf4..6a9e424 100644
--- a/src/translate/display.rs
+++ b/src/translate/display.rs
@@ -148,6 +148,18 @@ impl std::fmt::Display for MindustryProgram {
     }
 }
 
+fn format_unary_operator(operator: UnaryOperator) -> &'static str {
+    match operator {
+        UnaryOperator::Floor => "floor",
+        UnaryOperator::Round => "round",
+        UnaryOperator::Ceil => "ceil",
+        UnaryOperator::Rand => "rand",
+        UnaryOperator::Sqrt => "sqrt",
+        // Note: we use `equal x 0` to implement the binary NOT operation
+        UnaryOperator::Not => "equal",
+    }
+}
+
 fn format_condition(operator: Operator) -> &'static str {
     match operator {
         Operator::Eq => "equal",