From 8a1b739ae60cdba41b7d553efd4aef6ca5c01a3e Mon Sep 17 00:00:00 2001
From: yabu76 <yabu76@gmail.com>
Date: Sat, 15 Nov 2025 23:26:43 +0900
Subject: [PATCH] Add cleanup read to Lua API tio.expect[s]

tio.expect[s]() performs pattern matching for each character received,
but there are cases where the character reception speed exceeds the
pattern matching speed, resulting in characters being missed.

Add non-blocking reads to read all characters that have been received at
that time.
---
 src/script.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/src/script.c b/src/script.c
index e5b2f4f..74419ef 100644
--- a/src/script.c
+++ b/src/script.c
@@ -56,16 +56,22 @@ static char script_init[] =
 "    local ri = arg.RI or -1\n"
 "    tio.line_set(dtr, rts, cts, dsr, cd, ri)\n"
 "end\n"
+"tio.EXPECT_CLEANUP_READ_SIZE = 4096\n"
 "tio.expect = function(pattern, timeout)\n"
 "    local str = ''\n"
 "    while true do\n"
-"        local c = tio.read(1, timeout)\n"
-"        if c == nil then\n"
-"            return nil, str\n"
+"        local astr = tio.read(tio.EXPECT_CLEANUP_READ_SIZE, 0)\n"
+"        local c = nil\n"
+"        if astr == nil then\n"
+"            c = tio.read(1, timeout)\n"
+"            if c == nil then\n"
+"                return nil, str\n"
+"            end\n"
 "        end\n"
-"        str = str .. c\n"
-"        if string.match(str, pattern) then\n"
-"            return string.match(str, pattern), str\n"
+"        str = table.concat{str, astr or '', c or ''}\n"
+"        local captured = { string.match(str, pattern) }\n"
+"        if #captured > 0 then\n"
+"            return table.unpack(captured), str\n"
 "        end\n"
 "    end\n"
 "end\n"
@@ -75,11 +81,15 @@ static char script_init[] =
 "        patterns = { patterns }\n"
 "    end\n"
 "    while true do\n"
-"        local c = tio.read(1, timeout)\n"
-"        if c == nil then\n"
-"            return nil, nil, str\n"
+"        local astr = tio.read(tio.EXPECT_CLEANUP_READ_SIZE, 0)\n"
+"        local c = nil\n"
+"        if astr == nil then\n"
+"            c = tio.read(1, timeout)\n"
+"            if c == nil then\n"
+"                return nil, nil, str\n"
+"            end\n"
 "        end\n"
-"        str = str .. c\n"
+"        str = table.concat{str, astr or '', c or ''}\n"
 "        for idx, pat in ipairs(patterns) do\n"
 "            local captured = { string.match(str, pat) }\n"
 "            if #captured > 0 then\n"