compiler: implement multiple return support

pkg/compiler/return_test.go

@@ -0,0 +1,71 @@
+package compiler_test
+
+import (
+	"math/big"
+	"testing"
+)
+
+func TestMultipleReturn1(t *testing.T) {
+	src := `
+		package hello
+
+		func two() (int, int) {
+			return 5, 9
+		}
+
+		func Main() int {
+			a, _ := two()
+			return a
+		}
+	`
+	eval(t, src, big.NewInt(5))
+}
+
+func TestMultipleReturn2(t *testing.T) {
+	src := `
+		package hello
+
+		func two() (int, int) {
+			return 5, 9
+		}
+
+		func Main() int {
+			_, b := two()
+			return b
+		}
+	`
+	eval(t, src, big.NewInt(9))
+}
+
+func TestMultipleReturnWithArg(t *testing.T) {
+	src := `
+		package hello
+		
+		func inc2(a int) (int, int) {
+			return a+1, a+2 
+		}
+
+		func Main() int {
+			a, b := 3, 9
+			a, b = inc2(a)
+			return a+b
+		}
+	`
+	eval(t, src, big.NewInt(9))
+}
+
+func TestSingleReturn(t *testing.T) {
+	src := `
+		package hello
+
+		func inc(k int) int {
+			return k+1
+		}
+
+		func Main() int {
+			a, b := inc(3), inc(4)
+			return a+b
+		}
+	`
+	eval(t, src, big.NewInt(9))
+}