Introduce dedicated instruction for loop else

mitsuhiko · Nov 19, 2022 · d53160d · d53160d
1 parent 6e60023
commit d53160d
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Showing 3 changed files with 11 additions and 7 deletions.
diff --git a/minijinja/src/compiler/codegen.rs b/minijinja/src/compiler/codegen.rs
@@ -136,16 +136,13 @@ impl<'source> CodeGenerator<'source> {
     }
 
     /// Ends the open for loop
-    pub fn end_for_loop(&mut self, push_did_iterate: bool) {
+    pub fn end_for_loop(&mut self, push_did_not_iterate: bool) {
         match self.pending_block.pop() {
             Some(PendingBlock::Loop(iter_instr)) => {
                 self.add(Instruction::Jump(iter_instr));
                 let loop_end = self.next_instruction();
-                if push_did_iterate {
-                    self.add(Instruction::Lookup("loop"));
-                    self.add(Instruction::GetAttr("index0"));
-                    self.add(Instruction::LoadConst(Value::from(0)));
-                    self.add(Instruction::Eq);
+                if push_did_not_iterate {
+                    self.add(Instruction::PushDidNotIterate);
                 };
                 self.add(Instruction::PopFrame);
                 if let Some(Instruction::Iterate(ref mut jump_target)) =

diff --git a/minijinja/src/compiler/instructions.rs b/minijinja/src/compiler/instructions.rs
@@ -138,6 +138,9 @@ pub enum Instruction<'source> {
     /// ends and must point to a `PopFrame` instruction.
     Iterate(usize),
 
+    /// Push a bool that indicates that the loop iterated.
+    PushDidNotIterate,
+
     /// Pops the topmost frame
     PopFrame,
 

diff --git a/minijinja/src/vm/mod.rs b/minijinja/src/vm/mod.rs
@@ -350,7 +350,7 @@ impl<'env> Vm<'env> {
                     ctx_ok!(self.push_loop(state, a, *flags, pc, next_loop_recursion_jump.take()));
                 }
                 Instruction::Iterate(jump_target) => {
-                    let l = state.ctx.current_loop().expect("not inside a loop");
+                    let l = state.ctx.current_loop().unwrap();
                     l.object.idx.fetch_add(1, Ordering::Relaxed);
                     match l.iterator.next() {
                         Some(item) => stack.push(item),
@@ -360,6 +360,10 @@ impl<'env> Vm<'env> {
                         }
                     };
                 }
+                Instruction::PushDidNotIterate => {
+                    let l = state.ctx.current_loop().unwrap();
+                    stack.push(Value::from(l.object.idx.load(Ordering::Relaxed) == 0));
+                }
                 Instruction::Jump(jump_target) => {
                     pc = *jump_target;
                     continue;