refactor: 拆分编译流水线过程以避免逻辑漂移

crates/oxide_compiler/src/passes/expr/identifier.rs

@@ -0,0 +1,67 @@
+use super::*;
+
+impl Compiler {
+    pub(crate) fn count_identifier_expression(&self, expr: &Expression, ctx: &mut CompileCtx) {
+        let Expression::Identifier(ident) = expr else {
+            return;
+        };
+        let name = ident.name.as_str();
+
+        for up in &ctx.current_upvalue_captures {
+            if up.name == name {
+                ctx.alloc_reg();
+                ctx.count_instr();
+                return;
+            }
+        }
+
+        if ctx.scopes.symbols.lookup_is_captured(name) {
+            ctx.alloc_reg();
+            ctx.count_instr();
+            return;
+        }
+
+        if CompileCtx::is_known_builtin(name) {
+            let _ = ctx.lookup_or_builtin(name);
+        }
+        ctx.alloc_reg();
+        ctx.projected_pc += 1;
+    }
+
+    pub(crate) fn emit_identifier_expression(
+        &self, ident: &oxide_parser::IdentifierReference, ctx: &mut CompileCtx,
+    ) -> Result<u8, String> {
+        let name = ident.name.as_str();
+
+        for (uv_idx, up) in ctx.current_upvalue_captures.iter().enumerate() {
+            if up.name == name {
+                let r = ctx.alloc_reg();
+                let idx = uv_idx as u8;
+                ctx.emit(opcode::encode(OpCode::LOAD_UPVALUE, r, idx, 0));
+                return Ok(r);
+            }
+        }
+
+        if ctx.scopes.symbols.lookup_is_captured(name) {
+            let cell_idx = ctx
+                .scopes
+                .cell_registry
+                .iter()
+                .find(|(n, _)| n == name)
+                .map(|(_, idx)| *idx)
+                .unwrap_or(0);
+            let r = ctx.alloc_reg();
+            if let Some((binding, _)) = ctx.scopes.symbols.lookup_any_binding(name) {
+                ctx.emit(opcode::encode(OpCode::CELL_GET, r, binding.reg, cell_idx));
+            } else {
+                ctx.emit(opcode::encode(OpCode::CELL_GET, r, 0, cell_idx));
+            }
+            return Ok(r);
+        }
+
+        let var_reg = ctx.lookup_or_builtin(name)?;
+        let r = ctx.alloc_reg();
+        ctx.emit(opcode::encode(OpCode::LOAD_VAR, r, var_reg, 0));
+        Ok(r)
+    }
+}