From cba6a6fdea354f7655fe1a2cae3a03b54e8ffc0a Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Mon, 30 Dec 2019 10:45:56 +0100
Subject: [PATCH] `as` casting

---
 examples/news_fetcher.v    |  4 ++--
 vlib/builtin/int_test.v    |  4 ++++
 vlib/compiler/expression.v | 12 ++++++++++++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/examples/news_fetcher.v b/examples/news_fetcher.v
index 73c226db54..4807a5dd7d 100644
--- a/examples/news_fetcher.v
+++ b/examples/news_fetcher.v
@@ -6,7 +6,7 @@ import json
 import sync
 
 const (
-	NR_THREADS = 4
+	nr_threads = 4
 )
 
 struct Story {
@@ -73,7 +73,7 @@ fn main() {
 	fetcher.mu = &mtx
 	fetcher.wg = &wg
 	fetcher.wg.add(ids.len)
-	for i := 0; i < NR_THREADS; i++ {
+	for i := 0; i < nr_threads; i++ {
 		go fetcher.fetch()
 	}
 	fetcher.wg.wait()
diff --git a/vlib/builtin/int_test.v b/vlib/builtin/int_test.v
index d3fedf73d7..dd903d2f25 100644
--- a/vlib/builtin/int_test.v
+++ b/vlib/builtin/int_test.v
@@ -44,6 +44,10 @@ fn test_float_equal_operator() {
 	assert a.gtbit(1)
 	assert a >= 1
 	assert a.gebit(1)
+
+	f := 1.2
+	ab := f as int
+	assert ab == 1
 }
 
 fn test_str_methods() {
diff --git a/vlib/compiler/expression.v b/vlib/compiler/expression.v
index 44ceb98511..ad23e42b55 100644
--- a/vlib/compiler/expression.v
+++ b/vlib/compiler/expression.v
@@ -60,6 +60,18 @@ fn (p mut Parser) bool_expression() string {
 			p.gen('}, sizeof($typ) ), .typ = SumType_${tt} }')//${val}_type }')
 		}
 	}
+	// `as` cast
+	// TODO remove copypasta
+	if p.tok == .key_as {
+		p.next()
+		cast_typ := p.get_type()
+		if typ == cast_typ {
+			p.warn('casting `$typ` to `$cast_typ` is not needed')
+		}
+		p.cgen.set_placeholder(start_ph, '($cast_typ)(')
+		p.gen(')')
+		return cast_typ
+	}
 	return typ
 }