From 9be13d26ced58dda77cac4c71cbf0476c065c56e Mon Sep 17 00:00:00 2001
From: Koichi Nakamura <koichi@idein.jp>
Date: Mon, 4 Jan 2021 16:14:14 +0900
Subject: [PATCH] Add input stream stack

---
 bootstrap.fs | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/bootstrap.fs b/bootstrap.fs
index 577c234..12aeed8 100644
--- a/bootstrap.fs
+++ b/bootstrap.fs
@@ -1429,3 +1429,29 @@ W/O stdout_ file>fam c!
 
 \ do nothing
 :noname drop success ; stdout_ file>flush !
+
+( === Input Stream === )
+
+\ input stream stack
+struct
+    cell% field input>next
+    cell% field input>file
+    cell% field input>lineno
+end-struct input%
+
+variable input-streams
+0 input-streams !
+
+: push-input-stream ( file -- )
+    input% %allot   \ addr
+    swap over input>file !
+    0 over input>lineno !
+    input-streams @ over input>next !
+    input-streams !
+;
+
+: pop-input-stream ( -- )
+    input-streams @ input-streams !
+;
+
+stdin_ push-input-stream