diff options
| -rw-r--r-- | src/lstrlib.js | 70 | ||||
| -rw-r--r-- | tests/lstrlib.js | 34 |
2 files changed, 90 insertions, 14 deletions
diff --git a/src/lstrlib.js b/src/lstrlib.js index d6c642a..030e063 100644 --- a/src/lstrlib.js +++ b/src/lstrlib.js @@ -368,6 +368,8 @@ const NB = 8; /* mask for one character (NB 1's) */ const MC = ((1 << NB) - 1); +const MAXALIGN = 8; + /* ** information to pack/unpack stuff */ @@ -448,6 +450,22 @@ const getoption = function(h, fmt) { case 'i': r.size = getnumlimit(h, fmt, 4); r.opt = KOption.Kint; return r; // sizeof(int): 4 case 'I': r.size = getnumlimit(h, fmt, 4); r.opt = KOption.Kuint; return r; case 's': r.size = getnumlimit(h, fmt, 8); r.opt = KOption.Kstring; return r; + case 'c': { + r.size = getnum(fmt, -1); + if (r.size === -1) + lauxlib.luaL_error(h.L, "missing size for format option 'c'"); + r.opt = KOption.Kchar; + return r; + } + case 'z': r.opt = KOption.Kzstr; return r; + case 'x': r.size = 1; r.opt = KOption.Kpadding; return r; + case 'X': r.opt = KOption.Kpaddalign; return r; + case ' ': break; + case '<': h.islittle = true; break; + case '>': h.islittle = false; break; + case '=': h.islittle = true; break; + case '!': h.maxalign = getnumlimit(h, fmt, MAXALIGN); break; + default: lauxlib.luaL_error(h.L, `invalid format option '${r.opt}'`); } r.opt = KOption.Knop; @@ -529,7 +547,7 @@ const packnum = function(b, n, islittle, size) { const str_pack = function(L) { let b = []; let h = new Header(); - let fmt = lauxlib.luaL_checkstring(L, 1); /* format string */ + let fmt = lauxlib.luaL_checkstring(L, 1).split(''); /* format string */ let arg = 1; /* current argument to pack */ let totalsize = 0; /* accumulate total size of result */ lapi.lua_pushnil(L); /* mark to separate arguments from string buffer */ @@ -648,6 +666,29 @@ const str_byte = function(L) { return n; }; +const str_packsize = function(L) { + let h = new Header(L); + let fmt = lauxlib.luaL_checkstring(L, 1).split(''); + let totalsize = 0; /* accumulate total size of result */ + while (fmt.length > 0) { + let details = getdetails(h, totalsize, fmt); + let opt = details.opt; + let size = details.size; + let ntoalign = details.ntoalign; + size += ntoalign; /* total space used by option */ + lauxlib.luaL_argcheck(L, totalsize <= MAXSIZE - size - 1, "format result too large"); + totalsize += size; + switch (opt) { + case KOption.Kstring: /* strings with length count */ + case KOption.Kzstr: /* zero-terminated string */ + lauxlib.luaL_argerror(L, 1, "variable-length format"); + default: break; + } + } + lapi.lua_pushinteger(L, totalsize); + return 1; +}; + /* ** Unpack an integer with 'size' bytes and 'islittle' endianness. ** If size is smaller than the size of a Lua integer and integer @@ -689,7 +730,7 @@ const unpacknum = function(L, b, islittle, size) { const str_unpack = function(L) { let h = new Header(L); - let fmt = lauxlib.luaL_checkstring(L, 1); + let fmt = lauxlib.luaL_checkstring(L, 1).split(''); let data = lauxlib.luaL_checkstring(L, 2); data = L.stack[lapi.index2addr_(L, 2)]; let ld = data.length; @@ -747,18 +788,19 @@ const str_unpack = function(L) { }; const strlib = { - "byte": str_byte, - "char": str_char, - "dump": str_dump, - "format": str_format, - "len": str_len, - "lower": str_lower, - "pack": str_pack, - "rep": str_rep, - "reverse": str_reverse, - "sub": str_sub, - "unpack": str_unpack, - "upper": str_upper + "byte": str_byte, + "char": str_char, + "dump": str_dump, + "format": str_format, + "len": str_len, + "lower": str_lower, + "pack": str_pack, + "packsize": str_packsize, + "rep": str_rep, + "reverse": str_reverse, + "sub": str_sub, + "unpack": str_unpack, + "upper": str_upper }; const createmetatable = function(L) { diff --git a/tests/lstrlib.js b/tests/lstrlib.js index 23cd786..4185f04 100644 --- a/tests/lstrlib.js +++ b/tests/lstrlib.js @@ -459,4 +459,38 @@ test('string.dump', function (t) { "hello1212.5", "Correct element(s) on the stack" ); +}); + + +test('string.pack/unpack/packsize', function (t) { + let luaCode = ` + local s1, n, s2 = "hello", 2, "you" + local packed = string.pack("zjz", s1, n, s2) + local us1, un, us2 = string.unpack("zjz", packed) + return s1 == us1 and n == un and s2 == us2 + `, L; + + t.plan(3); + + t.doesNotThrow(function () { + + L = lauxlib.luaL_newstate(); + + linit.luaL_openlibs(L); + + lauxlib.luaL_loadstring(L, luaCode); + + }, "Lua program loaded without error"); + + t.doesNotThrow(function () { + + lapi.lua_call(L, 0, -1); + + }, "Lua program ran without error"); + + t.strictEqual( + lapi.lua_tostring(L, -1), + "FFFFFFF", + "Correct element(s) on the stack" + ); });
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