lua_stringtonumber, tonumber

2 files changed, 37 insertions, 1 deletions

diff --git a/src/lapi.js b/src/lapi.js
index bc4dd54..19e3090 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -488,6 +488,13 @@ const lua_topointer = function(L, idx) {
     }
 };
 
+const lua_stringtonumber = function(L, s) {
+    let number = parseFloat(s);
+    L.stack[L.top++] = new TValue(number % 1 !== 0 ? CT.LUA_TNUMFLT : CT.LUA_TNUMINT, number);
+    assert(L.top <= L.ci.top, "stack overflow");
+    return s.length;
+};
+
 const f_call = function(L, ud) {
     ldo.luaD_callnoyield(L, ud.funcOff, ud.nresults);
 };
@@ -705,4 +712,5 @@ module.exports.lua_error           = lua_error;
 module.exports.lua_insert          = lua_insert;
 module.exports.lua_gc              = lua_gc;
 module.exports.lua_getallocf       = lua_getallocf;
-module.exports.lua_getextraspace   = lua_getextraspace;
\ No newline at end of file
+module.exports.lua_getextraspace   = lua_getextraspace;
+module.exports.lua_stringtonumber  = lua_stringtonumber;
\ No newline at end of file
diff --git a/src/lbaselib.js b/src/lbaselib.js
index 19a990e..9cc4fb1 100644
--- a/src/lbaselib.js
+++ b/src/lbaselib.js
@@ -127,6 +127,33 @@ const luaB_ipairs = function(L) {
     return 3;
 };
 
+const luaB_tonumber = function(L) {
+    if (lapi.lua_type(L, 2) <= 0) {  /* standard conversion? */
+        lauxlib.luaL_checkany(L, 1);
+        if (lapi.lua_type(L, 1) === CT.LUA_TNUMBER) {  /* already a number? */
+            lapi.lua_settop(L, 1);
+            return 1;
+        } else {
+            let s = lapi.lua_tostring(L, 1);
+            if (s !== null && lapi.lua_stringtonumber(L, s) === s.length)
+                return 1;  /* successful conversion to number */
+        }
+    } else {
+        let base = lauxlib.luaL_checkinteger(L, 2);
+        lauxlib.luaL_checktype(L, 1, CT.LUA_TSTRING);  /* no numbers as strings */
+        let s = lapi.lua_tostring(L, 1);
+        lauxlib.luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
+        let n = parseInt(s, base);
+        if (!isNaN(n)) {
+            lapi.lua_pushinteger(L, n);
+            return 1;
+        }
+    }
+
+    lapi.lua_pushnil(L);
+    return 1;
+};
+
 const luaB_error = function(L) {
     let level = lauxlib.luaL_optinteger(L, 2, 1);
     lapi.lua_settop(L, 1);
@@ -195,6 +222,7 @@ const base_funcs = {
     "collectgarbage": function () {},
     "print":          luaB_print,
     "tostring":       luaB_tostring,
+    "tonumber":       luaB_tonumber,
     "getmetatable":   luaB_getmetatable,
     "ipairs":         luaB_ipairs,
     "select":         luaB_select,