From 0a10a789a588fa5a463b29722a6e472384daad6b Mon Sep 17 00:00:00 2001
From: LemonInTheDark <58055496+LemonInTheDark@users.noreply.github.com>
Date: Thu, 5 Oct 2023 15:34:19 -0700
Subject: [PATCH] Adds support for %% and its derivatives

I'm assuming this handles operator overloading automatically.
Nothin much else to say, outside that I needed to roll my own operation
for this one, since float remainder is kinda hard to find (and I
couldn't after cursory reading)
---
 crates/dreammaker/src/ast.rs       |  5 +++++
 crates/dreammaker/src/constants.rs |  8 ++++++++
 crates/dreammaker/src/lexer.rs     |  3 +++
 crates/dreammaker/src/parser.rs    | 10 ++++++++--
 4 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/crates/dreammaker/src/ast.rs b/crates/dreammaker/src/ast.rs
index 49d8086a..3c1cb677 100644
--- a/crates/dreammaker/src/ast.rs
+++ b/crates/dreammaker/src/ast.rs
@@ -113,6 +113,7 @@ pub enum BinaryOp {
     Div,
     Pow,
     Mod,
+    FloatMod,
     Eq,
     NotEq,
     Less,
@@ -142,6 +143,7 @@ impl fmt::Display for BinaryOp {
             Div => "/",
             Pow => "**",
             Mod => "%",
+            FloatMod => "%%",
             Eq => "==",
             NotEq => "!=",
             Less => "<",
@@ -172,6 +174,7 @@ pub enum AssignOp {
     MulAssign,
     DivAssign,
     ModAssign,
+    FloatModAssign,
     AssignInto,
     BitAndAssign,
     AndAssign,
@@ -192,6 +195,7 @@ impl fmt::Display for AssignOp {
             MulAssign => "*=",
             DivAssign => "/=",
             ModAssign => "%=",
+            FloatModAssign => "%%=",
             AssignInto => ":=",
             BitAndAssign => "&=",
             AndAssign => "&&=",
@@ -233,6 +237,7 @@ augmented! {
     Mul = MulAssign;
     Div = DivAssign;
     Mod = ModAssign;
+    FloatMod = FloatModAssign;
     BitAnd = BitAndAssign;
     BitOr = BitOrAssign;
     BitXor = BitXorAssign;
diff --git a/crates/dreammaker/src/constants.rs b/crates/dreammaker/src/constants.rs
index 40adc04d..c75a240c 100644
--- a/crates/dreammaker/src/constants.rs
+++ b/crates/dreammaker/src/constants.rs
@@ -684,6 +684,14 @@ impl<'a> ConstantFolder<'a> {
         numeric!(LessEq <=);
         numeric!(Greater >);
         numeric!(GreaterEq >=);
+        match (op, lhs, rhs) {
+            (BinaryOp::FloatMod, Float(lhs), Float(rhs)) => return Ok(Constant::from(lhs - ((lhs / rhs).floor() * rhs))),
+            (_, lhs_, rhs_) => {
+                lhs = lhs_;
+                rhs = rhs_;
+            }
+        }
+
         match (op, lhs, rhs) {
             (BinaryOp::Pow, Float(lhs), Float(rhs)) => return Ok(Constant::from(lhs.powf(rhs))),
             (_, lhs_, rhs_) => {
diff --git a/crates/dreammaker/src/lexer.rs b/crates/dreammaker/src/lexer.rs
index ed4c46d2..68627ce5 100644
--- a/crates/dreammaker/src/lexer.rs
+++ b/crates/dreammaker/src/lexer.rs
@@ -75,6 +75,8 @@ table! {
     "##",  TokenPaste;
     "%",   Mod;
     "%=",  ModAssign;
+    "%%",  FloatMod;
+    "%%=", FloatModAssign;
     "&",   BitAnd;
     "&&",  And;
     "&&=", AndAssign;
@@ -278,6 +280,7 @@ impl Token {
                 Eq |
                 NotEq |
                 Mod |
+                FloatMod |
                 And |
                 BitAndAssign |
                 AndAssign |
diff --git a/crates/dreammaker/src/parser.rs b/crates/dreammaker/src/parser.rs
index cde62424..08d02db4 100644
--- a/crates/dreammaker/src/parser.rs
+++ b/crates/dreammaker/src/parser.rs
@@ -150,11 +150,12 @@ oper_table! { BINARY_OPS;
     Pow {
         (BinaryOp, Pow),
     }
-    // * / %
+    // * / % %%
     Mul {
         (BinaryOp, Mul), //
         (BinaryOp, Div = Slash), //
         (BinaryOp, Mod),
+        (BinaryOp, FloatMod),
     }
     // + -
     Add {
@@ -205,7 +206,7 @@ oper_table! { BINARY_OPS;
     Conditional {
         (TernaryOp, Conditional = QuestionMark),
     }
-    // = += -= -= *= /= %= &= |= ^= <<= >>=
+    // = += -= -= *= /= %= %%= &= |= ^= <<= >>=
     Assign {
         (AssignOp, Assign),
         (AssignOp, AddAssign),
@@ -213,6 +214,7 @@ oper_table! { BINARY_OPS;
         (AssignOp, MulAssign),
         (AssignOp, DivAssign),
         (AssignOp, ModAssign),
+        (AssignOp, FloatModAssign),
         (AssignOp, BitAndAssign),
         (AssignOp, BitOrAssign),
         (AssignOp, BitXorAssign),
@@ -887,6 +889,10 @@ impl<'ctx, 'an, 'inp> Parser<'ctx, 'an, 'inp> {
             last_part.push('%');
         } else if self.exact(Punct(ModAssign))?.is_some() {
             last_part.push_str("%=");
+        } else if self.exact(Punct(FloatMod))?.is_some() {
+            last_part.push_str("%%");
+        } else if self.exact(Punct(FloatModAssign))?.is_some() {
+            last_part.push_str("%%=");
         } else if self.exact(Punct(BitAnd))?.is_some() {
             last_part.push('&');
         } else if self.exact(Punct(BitAndAssign))?.is_some() {