From 1e64a6a2f623a6f6a3ce1b0b10ccfe40acbcdde4 Mon Sep 17 00:00:00 2001
From: Alexander Gavrilov <angavrilov@gmail.com>
Date: Mon, 16 Apr 2012 18:05:42 +0400
Subject: [PATCH] Make dfhack.lineedit automatically interact with
 RunCoreQueryLoop.

It still falls back to the original waiting mode if yield fails.
---
 library/LuaTools.cpp   | 62 +++++++++++++++++++++++++++++++++++++-----
 library/lua/dfhack.lua | 11 +-------
 2 files changed, 56 insertions(+), 17 deletions(-)

diff --git a/library/LuaTools.cpp b/library/LuaTools.cpp
index 993efa747..be4fa864e 100644
--- a/library/LuaTools.cpp
+++ b/library/LuaTools.cpp
@@ -240,15 +240,14 @@ static int lua_dfhack_is_interactive(lua_State *S)
     return 1;
 }
 
-static int lua_dfhack_lineedit(lua_State *S)
+static int dfhack_lineedit_sync(lua_State *S, Console *pstream)
 {
-    const char *prompt = luaL_optstring(S, 1, ">> ");
-    const char *hfile = luaL_optstring(S, 2, NULL);
-
-    Console *pstream = get_console(S);
     if (!pstream)
         return 2;
 
+    const char *prompt = luaL_optstring(S, 1, ">> ");
+    const char *hfile = luaL_optstring(S, 2, NULL);
+
     DFHack::CommandHistory hist;
     if (hfile)
         hist.load(hfile);
@@ -271,6 +270,47 @@ static int lua_dfhack_lineedit(lua_State *S)
     }
 }
 
+static int DFHACK_QUERY_COROTABLE_TOKEN = 0;
+
+static int yield_helper(lua_State *S)
+{
+    return lua_yield(S, lua_gettop(S));
+}
+
+namespace {
+    int dfhack_lineedit_cont(lua_State *L, int status, int)
+    {
+        if (Lua::IsSuccess(status))
+            return lua_gettop(L) - 2;
+        else
+            return dfhack_lineedit_sync(L, get_console(L));
+    }
+}
+
+static int dfhack_lineedit(lua_State *S)
+{
+    lua_settop(S, 2);
+
+    Console *pstream = get_console(S);
+    if (!pstream)
+        return 2;
+
+    lua_rawgetp(S, LUA_REGISTRYINDEX, &DFHACK_QUERY_COROTABLE_TOKEN);
+    lua_rawgetp(S, -1, S);
+    bool in_coroutine = !lua_isnil(S, -1);
+    lua_settop(S, 2);
+
+    if (in_coroutine)
+    {
+        lua_pushcfunction(S, yield_helper);
+        lua_pushvalue(S, 1);
+        lua_pushvalue(S, 2);
+        return Lua::TailPCallK<dfhack_lineedit_cont>(S, 2, LUA_MULTRET, 0, 0);
+    }
+
+    return dfhack_lineedit_sync(S, pstream);
+}
+
 /*
  * Exception handling
  */
@@ -796,10 +836,12 @@ bool DFHack::Lua::RunCoreQueryLoop(color_ostream &out, lua_State *state,
             return false;
         }
 
+        lua_rawgetp(state, LUA_REGISTRYINDEX, &DFHACK_QUERY_COROTABLE_TOKEN);
         lua_pushvalue(state, base+1);
         lua_remove(state, base+1);
         thread = Lua::NewCoroutine(state);
-        lua_rawsetp(state, LUA_REGISTRYINDEX, thread);
+        lua_rawsetp(state, -2, thread);
+        lua_pop(state, 1);
 
         rv = resume_query_loop(out, thread, state, lua_gettop(state)-base, prompt, histfile);
     }
@@ -839,8 +881,10 @@ bool DFHack::Lua::RunCoreQueryLoop(color_ostream &out, lua_State *state,
     {
         CoreSuspender suspend;
 
+        lua_rawgetp(state, LUA_REGISTRYINDEX, &DFHACK_QUERY_COROTABLE_TOKEN);
         lua_pushnil(state);
-        lua_rawsetp(state, LUA_REGISTRYINDEX, thread);
+        lua_rawsetp(state, -2, thread);
+        lua_pop(state, 1);
     }
 
     return (rv == LUA_OK);
@@ -1180,6 +1224,10 @@ lua_State *DFHack::Lua::Open(color_ostream &out, lua_State *state)
     luaL_openlibs(state);
     AttachDFGlobals(state);
 
+    // Table of query coroutines
+    lua_newtable(state);
+    lua_rawsetp(state, LUA_REGISTRYINDEX, &DFHACK_QUERY_COROTABLE_TOKEN);
+
     // Replace the print function of the standard library
     lua_pushcfunction(state, lua_dfhack_println);
     lua_setglobal(state, "print");
diff --git a/library/lua/dfhack.lua b/library/lua/dfhack.lua
index 595363da8..b5985f0c1 100644
--- a/library/lua/dfhack.lua
+++ b/library/lua/dfhack.lua
@@ -130,15 +130,6 @@ end
 
 -- Interactive
 
-function dfhack.query(prompt,hfile)
-    local _,main = coroutine.running()
-    if main then
-        return dfhack.lineedit(prompt,hfile)
-    else
-        return coroutine.yield(prompt,hfile)
-    end
-end
-
 local print_banner = true
 
 function dfhack.interpreter(prompt,hfile,env)
@@ -163,7 +154,7 @@ function dfhack.interpreter(prompt,hfile,env)
     setmetatable(prompt_env, { __index = env or _G })
 
     while true do
-        local cmdline = dfhack.query(prompt_str, hfile)
+        local cmdline = dfhack.lineedit(prompt_str, hfile)
 
         if cmdline == nil or cmdline == 'quit' then
             break