Fnished 'src/techniques.md'.

Author: gnu4cn

scripts/c_func_tips/a

@@ -0,0 +1,6 @@
+local mylib = require "mylib"
+
+t = {1, "a", "this", 3.14}
+
+print( mylib.t_concat(t) )
+

scripts/c_func_tips/demo_tconcat.lua

@@ -0,0 +1,8 @@
+local mylib = require "mylib"
+
+x = mylib.new_tuple(10, "hi", {}, 3)
+print(x(1))
+print(x(2))
+print(x())
+
+print(x(10))

scripts/c_func_tips/demo_tuple.lua

@@ -0,0 +1,7 @@
+local mylib = require "mylib"
+
+c1 = mylib.newCounter()
+print(c1(), c1(), c1())
+
+c2 = mylib.newCounter()
+print(c2(), c2(), c1())

scripts/c_func_tips/demo_upvalue.lua

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include "lua.h"
+#include "lauxlib.h"
+
+
+void main () {
+    char* myStr = "测试字符串";
+    lua_State *L = luaL_newstate(); /* opens Lua */
+
+    /* variable with a unique address */
+    static char Key = 'k';
+
+    /* store a string */
+    lua_pushstring(L, myStr); /* push value */
+    lua_rawsetp(L, LUA_REGISTRYINDEX, (void *)&Key); /* registry[&Key] = myStr */
+
+    /* retrieve a string */
+    lua_rawgetp(L, LUA_REGISTRYINDEX, (void *)&Key); /* retrieve value */
+    myStr = lua_tostring(L, -1); /* convert to string */
+
+    printf("%s\n", myStr);
+}

scripts/c_func_tips/main.c

@@ -2,6 +2,37 @@
 #include "lauxlib.h"
 #include "tips_lib.h"
 
+int t_tuple (lua_State *L) {
+    lua_Integer op = luaL_optinteger(L, 1, 0);
+    if (op == 0) { /* no arguments? */
+        int i;
+        /* push each valid upvalue onto the stack */
+        for (i = 1; !lua_isnone(L, lua_upvalueindex(i)); i++)
+            lua_pushvalue(L, lua_upvalueindex(i));
+        return i - 1; /* number of values */
+    }
+    else { /* get field 'op' */
+        luaL_argcheck(L, 0 < op && op <= 256, 1,
+                "index out of range");
+        if (lua_isnone(L, lua_upvalueindex(op)))
+            return 0; /* no such field */
+        lua_pushvalue(L, lua_upvalueindex(op));
+        return 1;
+    }
+}
+
+int t_new (lua_State *L) {
+    int top = lua_gettop(L);
+    luaL_argcheck(L, top < 256, top, "too many fields");
+    lua_pushcclosure(L, t_tuple, top);
+    return 1;
+}
+
+int newCounter (lua_State *L) {
+    lua_pushinteger(L, 0);
+    lua_pushcclosure(L, &counter, 1);
+    return 1;
+}
 
 int l_map (lua_State *L) {
     int i, n;
@@ -26,6 +57,9 @@ int l_map (lua_State *L) {
 static const struct luaL_Reg mylib [] = {
     {"map", l_map},
     {"split", l_split},
+    {"new_tuple", t_new},
+    {"t_concat", tconcat},
+    {"newCounter", newCounter},
     {NULL, NULL} /* sentinel */
 };
 

scripts/c_func_tips/mylib.so

@@ -4,9 +4,6 @@
 #include <string.h>
 #include "lua.h"
 
-extern int l_map (lua_State *L);
-extern int luaopen_mylib (lua_State *L);
-
 static int l_split (lua_State *L) {
     const char *s = luaL_checkstring(L, 1); /* subject */
     const char *sep = luaL_checkstring(L, 2); /* separator */
@@ -29,4 +26,29 @@ static int l_split (lua_State *L) {
     return 1; /* return the table */
 }
 
+
+static int tconcat (lua_State *L) {
+    luaL_Buffer b;
+    int i, n;
+
+    luaL_checktype(L, 1, LUA_TTABLE);
+    n = luaL_len(L, 1);
+    luaL_buffinit(L, &b);
+
+    for (i = 1; i <= n; i++) {
+        lua_geti(L, 1, i); /* get string from table */
+        luaL_addvalue(&b); /* add it to the buffer */
+    }
+
+    luaL_pushresult(&b);
+    return 1;
+}
+
+static int counter (lua_State *L) {
+    int val = lua_tointeger(L, lua_upvalueindex(1));
+    lua_pushinteger(L, ++val); /* new value */
+    lua_copy(L, -1, lua_upvalueindex(1)); /* update upvalue */
+    return 1; /* return new value */
+}
+
 #endif

scripts/c_func_tips/tips_lib.c

@@ -1,4 +1,3 @@
-
 #ifndef EXTENDING_LIB_H
 #define EXTENDING_LIB_H