From 4242e7610fc2d2798e4a483963e4f908842510ac Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Thu, 5 May 2022 00:25:58 +0800
Subject: [PATCH] checker: add comptime_selector() (#14286)

---
 vlib/v/checker/checker.v  | 23 +----------------------
 vlib/v/checker/comptime.v | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 62b7b52f0c..abd604dc2a 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -2663,28 +2663,7 @@ pub fn (mut c Checker) expr(node_ ast.Expr) ast.Type {
 			return c.comptime_call(mut node)
 		}
 		ast.ComptimeSelector {
-			node.left_type = c.expr(node.left)
-			expr_type := c.unwrap_generic(c.expr(node.field_expr))
-			expr_sym := c.table.sym(expr_type)
-			if expr_type != ast.string_type {
-				c.error('expected `string` instead of `$expr_sym.name` (e.g. `field.name`)',
-					node.field_expr.pos())
-			}
-			if mut node.field_expr is ast.SelectorExpr {
-				left_pos := node.field_expr.expr.pos()
-				if c.comptime_fields_type.len == 0 {
-					c.error('compile time field access can only be used when iterating over `T.fields`',
-						left_pos)
-				}
-				expr_name := node.field_expr.expr.str()
-				if expr_name in c.comptime_fields_type {
-					return c.comptime_fields_type[expr_name]
-				}
-				c.error('unknown `\$for` variable `$expr_name`', left_pos)
-			} else {
-				c.error('expected selector expression e.g. `$(field.name)`', node.field_expr.pos())
-			}
-			return ast.void_type
+			return c.comptime_selector(mut node)
 		}
 		ast.ConcatExpr {
 			return c.concat_expr(mut node)
diff --git a/vlib/v/checker/comptime.v b/vlib/v/checker/comptime.v
index 8138105bef..0175364894 100644
--- a/vlib/v/checker/comptime.v
+++ b/vlib/v/checker/comptime.v
@@ -90,6 +90,30 @@ fn (mut c Checker) comptime_call(mut node ast.ComptimeCall) ast.Type {
 	return f.return_type
 }
 
+fn (mut c Checker) comptime_selector(mut node ast.ComptimeSelector) ast.Type {
+	node.left_type = c.expr(node.left)
+	expr_type := c.unwrap_generic(c.expr(node.field_expr))
+	expr_sym := c.table.sym(expr_type)
+	if expr_type != ast.string_type {
+		c.error('expected `string` instead of `$expr_sym.name` (e.g. `field.name`)', node.field_expr.pos())
+	}
+	if mut node.field_expr is ast.SelectorExpr {
+		left_pos := node.field_expr.expr.pos()
+		if c.comptime_fields_type.len == 0 {
+			c.error('compile time field access can only be used when iterating over `T.fields`',
+				left_pos)
+		}
+		expr_name := node.field_expr.expr.str()
+		if expr_name in c.comptime_fields_type {
+			return c.comptime_fields_type[expr_name]
+		}
+		c.error('unknown `\$for` variable `$expr_name`', left_pos)
+	} else {
+		c.error('expected selector expression e.g. `$(field.name)`', node.field_expr.pos())
+	}
+	return ast.void_type
+}
+
 fn (mut c Checker) comptime_for(node ast.ComptimeFor) {
 	typ := c.unwrap_generic(node.typ)
 	sym := c.table.sym(typ)