Add array destructuring

src/lparser.cpp

@@ -3668,7 +3668,6 @@ static void checktoclose (FuncState *fs, int level) {
 
 
 static void restdestructuring (LexState *ls, int line, std::vector<std::pair<TString*, expdesc>>& pairs) {
-  check_match(ls, '}', '{', line);
   checknext(ls, '=');
 
   /* begin scope of the locals we want to create */
@@ -3721,14 +3720,30 @@ static void destructuring (LexState *ls) {
   std::vector<std::pair<TString*, expdesc>> pairs{};
   luaX_next(ls); /* skip '{' */
   do {
-    TString* var = str_checkname(ls);
+    TString* var = str_checkname(ls, true);
     TString* prop = var;
     if (testnext(ls, '='))
       prop = str_checkname(ls);
     expdesc propexp;
     codestring(&propexp, prop);
     pairs.emplace_back(var, std::move(propexp));
   } while (testnext(ls, ','));
+  check_match(ls, '}', '{', line);
+  restdestructuring(ls, line, pairs);
+}
+
+static void arraydestructuring (LexState *ls) {
+  auto line = ls->getLineNumber();
+  std::vector<std::pair<TString*, expdesc>> pairs{};
+  luaX_next(ls); /* skip '[' */
+  expdesc prop;
+  init_exp(&prop, VKINT, 0);
+  prop.u.ival = 1;
+  do {
+    pairs.emplace_back(str_checkname(ls, true), prop);
+    prop.u.ival++;
+  } while (testnext(ls, ','));
+  check_match(ls, ']', '[', line);
   restdestructuring(ls, line, pairs);
 }
 
@@ -3738,6 +3753,10 @@ static void localstat (LexState *ls) {
     destructuring(ls);
     return;
   }
+  if (ls->t.token == '[') {
+    arraydestructuring(ls);
+    return;
+  }
   /* stat -> LOCAL NAME ATTRIB { ',' NAME ATTRIB } ['=' explist] */
   FuncState *fs = ls->fs;
   int toclose = -1;  /* index of to-be-closed variable (if any) */

tests/basic.pluto

@@ -1016,6 +1016,20 @@ do
     }
     assert(i == 69)
 end
+-- Array destructuring
+do
+    local [a, b, c] = { 1, 2, 3 }
+    assert(a == 1)
+    assert(b == 2)
+    assert(c == 3)
+end
+do
+    local t = { 1, 2, 3 }
+    local [a, b, c] = t
+    assert(a == 1)
+    assert(b == 2)
+    assert(c == 3)
+end
 
 print "Testing compatibility."
 do