From 1ba5996404d43531562820db3c8a709a438abc59 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Mon, 29 Jun 2020 10:53:12 +0300
Subject: [PATCH] parser: fix interface functions with no params (ui examples)

---
 vlib/v/parser/fn.v                            |  3 ++-
 .../tests/fn_type_only_args_in_interfaces.out |  5 +++++
 .../tests/fn_type_only_args_in_interfaces.vv  | 22 +++++++++++++++++++
 .../tests/fn_type_only_args_unknown_name.out  |  5 +++--
 4 files changed, 32 insertions(+), 3 deletions(-)
 create mode 100755 vlib/v/parser/tests/fn_type_only_args_in_interfaces.out
 create mode 100644 vlib/v/parser/tests/fn_type_only_args_in_interfaces.vv

diff --git a/vlib/v/parser/fn.v b/vlib/v/parser/fn.v
index 0ea5e45f7..cf49cec57 100644
--- a/vlib/v/parser/fn.v
+++ b/vlib/v/parser/fn.v
@@ -367,7 +367,8 @@ fn (mut p Parser) fn_args() ([]table.Arg, bool, bool) {
 	mut args := []table.Arg{}
 	mut is_variadic := false
 	// `int, int, string` (no names, just types)
-	types_only := p.tok.kind in [.amp, .ellipsis, .key_fn] || (p.peek_tok.kind in [.comma, .rpar] && p.table.known_type(p.tok.lit))
+	types_only := p.tok.kind in [.amp, .ellipsis, .key_fn] || (p.peek_tok.kind == .comma && p.table.known_type(p.tok.lit)) ||
+		p.peek_tok.kind == .rpar
 	// TODO copy pasta, merge 2 branches
 	if types_only {
 		// p.warn('types only')
diff --git a/vlib/v/parser/tests/fn_type_only_args_in_interfaces.out b/vlib/v/parser/tests/fn_type_only_args_in_interfaces.out
new file mode 100755
index 000000000..0ce9615bb
--- /dev/null
+++ b/vlib/v/parser/tests/fn_type_only_args_in_interfaces.out
@@ -0,0 +1,5 @@
+vlib/v/parser/tests/fn_type_only_args_in_interfaces.v:22:1: error: `syntax_error` evaluated but not used 
+   20 | }
+   21 | 
+   22 | syntax_error
+      | ~~~~~~~~~~~~
diff --git a/vlib/v/parser/tests/fn_type_only_args_in_interfaces.vv b/vlib/v/parser/tests/fn_type_only_args_in_interfaces.vv
new file mode 100644
index 000000000..0a3e83966
--- /dev/null
+++ b/vlib/v/parser/tests/fn_type_only_args_in_interfaces.vv
@@ -0,0 +1,22 @@
+
+struct Type1 {}
+struct Type2 {}
+struct Type3 {}
+
+
+pub interface Widget1 {
+  init(Type1, Type2)
+}
+
+pub interface Widget2 {
+  init(Type1)
+  draw(Type2, Type3)
+}
+
+pub interface Widget3 {
+  fnoparams1()
+  fnoparams2()
+  draw(Type1, Type2)
+}
+
+syntax_error
diff --git a/vlib/v/parser/tests/fn_type_only_args_unknown_name.out b/vlib/v/parser/tests/fn_type_only_args_unknown_name.out
index a91e79972..f90443c8e 100644
--- a/vlib/v/parser/tests/fn_type_only_args_unknown_name.out
+++ b/vlib/v/parser/tests/fn_type_only_args_unknown_name.out
@@ -1,5 +1,6 @@
-vlib/v/parser/tests/fn_type_only_args_unknown_name.v:1:16: error: unexpected `{`, expecting `,` 
+vlib/v/parser/tests/fn_type_only_args_unknown_name.v:2:1: error: functions with type only args can not have bodies 
     1 | fn test(param) {
-      |                ^
     2 | }
+      | ^
     3 | 
+    4 | fn main() {
-- 
2.39.5