From c7f07cd0b6a0f44dc73e3c1c269a9d5c1f430136 Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Tue, 4 Feb 2020 07:37:38 +0100
Subject: [PATCH] v2: postfix_expr() checker

---
 vlib/v/ast/ast.v         |  1 +
 vlib/v/checker/checker.v | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/vlib/v/ast/ast.v b/vlib/v/ast/ast.v
index 951e746763..1246f6331a 100644
--- a/vlib/v/ast/ast.v
+++ b/vlib/v/ast/ast.v
@@ -235,6 +235,7 @@ pub struct PostfixExpr {
 pub:
 	op   token.Kind
 	expr Expr
+	pos  token.Position
 }
 
 pub struct PrefixExpr {
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 7a20eaa0ac..13c3cd04dd 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -242,7 +242,7 @@ pub fn (c &Checker) expr(node ast.Expr) table.Type {
 		}
 		// ast.FloatLiteral {}
 		ast.PostfixExpr {
-			return c.expr(it.expr)
+			return c.postfix_expr(it)
 		}
 		/*
 		ast.UnaryExpr {
@@ -309,6 +309,22 @@ pub fn (c &Checker) expr(node ast.Expr) table.Type {
 	return table.void_type
 }
 
+pub fn (c &Checker) postfix_expr(node ast.PostfixExpr) table.Type {
+	/*
+	match node.expr {
+		ast.IdentVar {
+			println('postfix identvar')
+		}
+		else {}
+	}
+	*/
+	typ := c.expr(node.expr)
+	if typ.kind != .int {
+		c.error('invalid operation: $node.op.str() (non-numeric type `$typ.name`)', node.pos)
+	}
+	return typ
+}
+
 pub fn (c &Checker) index_expr(node ast.IndexExpr) table.Type {
 	mut typ := c.expr(node.left)
 	mut is_range := false // TODO is_range := node.index is ast.RangeExpr