add chan type (#1)

* [vartype] add chantype because it is used with yletool

* debug

* more

pkg/vartype.go

@@ -90,6 +90,8 @@ func variableType(variable ast.Expr, depth int, hyphen bool, imports map[string]
 			varTypes = append(varTypes, variableType(arg, depth, hyphen, imports))
 		}
 		return sprintf(funcName+"(%s)", join(varTypes, ", "))
+	case *ast.ChanType:
+		return sprintf("chan")
 	case *ast.CompositeLit:
 		eltsType := variableType(t.Type, depth, hyphen, imports)
 		varTypes := []varTypeOutput{}