refactor: 清除旧代码并展开 crate

crates/oxide_compiler/src/stmt/iteration/while_loop.rs

@@ -0,0 +1,41 @@
+use crate::compiler::{CompileCtx, Compiler, Label};
+use oxide_bytecode::opcode;
+use oxide_parser::Statement;
+
+impl Compiler {
+    pub(crate) fn count_while_statement(&self, stmt: &oxide_parser::WhileStatement<'_>, ctx: &mut CompileCtx) {
+        let id = ctx.next_label_id();
+        let start_label = Label::WhileStart(id);
+        let end_label = Label::WhileEnd(id);
+        ctx.labels.label_map.insert(start_label, ctx.projected_pc);
+        self.count_expression(&stmt.test, ctx);
+        ctx.projected_pc += 1;
+        self.count_statement(&stmt.body, ctx);
+        ctx.projected_pc += 1;
+        ctx.labels.label_map.insert(end_label, ctx.projected_pc);
+    }
+
+    pub(crate) fn emit_while_statement(&self, stmt: &Statement, ctx: &mut CompileCtx) -> Result<Option<u8>, String> {
+        let Statement::WhileStatement(wh) = stmt else {
+            return Ok(None);
+        };
+        let id = ctx.next_label_id();
+        let start_label = Label::WhileStart(id);
+        let end_label = Label::WhileEnd(id);
+        ctx.push_loop(end_label, start_label);
+        let n_labeled = ctx.take_pending_loop_labels(end_label, start_label);
+        let test_reg = self.emit_expression(&wh.test, ctx)?;
+        let end_pos = ctx.resolve_label(end_label)?;
+        let offset = (end_pos as isize) - (ctx.bytecode.len() as isize);
+        let offset = ctx.checked_jump_offset(offset);
+        ctx.emit(opcode::encode_jmp_if_false(test_reg, offset));
+        self.emit_statement(&wh.body, ctx)?;
+        let start_pos = ctx.resolve_label(start_label)?;
+        let offset = (start_pos as isize) - (ctx.bytecode.len() as isize);
+        let offset = ctx.checked_jump_offset(offset);
+        ctx.emit(opcode::encode_jmp(offset));
+        ctx.pop_label_scopes(n_labeled);
+        ctx.pop_loop();
+        Ok(None)
+    }
+}