diff options
Diffstat (limited to 'src/lvm.js')
| -rw-r--r-- | src/lvm.js | 29 |
1 files changed, 20 insertions, 9 deletions
@@ -937,6 +937,18 @@ const isemptystr = function(o) { return o.ttisstring() && o.vslen() === 0; }; +/* copy strings in stack from top - n up to top - 1 to buffer */ +const copy2buff = function(L, top, n, buff) { + let tl = 0; /* size already copied */ + do { + let tv = L.stack[top-n]; + let l = tv.vslen(); /* length of string being copied */ + let s = tv.svalue(); + buff.set(s, tl); + tl += l; + } while (--n > 0); +}; + /* ** Main operation for concatenation: concat 'total' values in the stack, ** from 'L->top - total' up to 'L->top - 1'. @@ -955,16 +967,15 @@ const luaV_concat = function(L, total) { lobject.setobjs2s(L, top - 2, top - 1); } else { /* at least two non-empty string values; get as many as possible */ - let toconcat = new Array(total); - toconcat[total-1] = L.stack[top-1].svalue(); - for (n = 1; n < total; n++) { - if (!tostring(L, top - n - 1)) { - toconcat = toconcat.slice(total-n); - break; - } - toconcat[total-n-1] = L.stack[top - n - 1].svalue(); + let tl = L.stack[top-1].vslen(); + /* collect total length and number of strings */ + for (n = 1; n < total && tostring(L, top - n - 1); n++) { + let l = L.stack[top - n - 1].vslen(); + tl += l; } - let ts = lstring.luaS_bless(L, Array.prototype.concat.apply([], toconcat)); + let buff = new Uint8Array(tl); + copy2buff(L, top, n, buff); + let ts = lstring.luaS_bless(L, buff); lobject.setsvalue2s(L, top - n, ts); } total -= n - 1; /* got 'n' strings to create 1 new */ |