I relaxed the grammar to support in the parser for initial values of

variables to not require type annotation, like

var x : list (operation) := []

Parser.mly

@@ -368,7 +368,7 @@ const_decl:
   }
 
 var_decl:
-  Var var COLON type_expr ASS expr option(SEMI) {
+  Var var COLON var_decl_type_expr ASS expr option(SEMI) {
     let stop =
       match $7 with
         Some region -> region
@@ -384,30 +384,73 @@ var_decl:
       terminator = $7}
     in {region; value}
   }
-(*
 | Var var COLON type_name type_tuple
   ASS extended_expr option(SEMI) {
-    let stop =
+    let region    = cover $4.region $5.region in
-      match $7 with
+    let type_app  = TypeApp {region; value=$4,$5} in
-        Some region -> region
+    let cartesian = {region; value = type_app, []} in
-      |        None -> expr_to_region $6 in
+    let var_type  = Prod cartesian in
-    let region = cover $1 stop in
+    let stop      = match $8 with
+                      Some region -> region
+                    |        None -> $7.region in
+    let region    = cover $1 stop in
+    let init =
+      match $7.value with
+        `Expr e -> e
+      | `EList (lbracket, rbracket) ->
+           let region = $7.region
+           and value = {
+             lbracket;
+             rbracket;
+             colon = Region.ghost;
+             list_type = var_type} in
+           let value = {
+             lpar   = Region.ghost;
+             inside = value;
+             rpar   = Region.ghost} in
+           ListExpr (EmptyList {region; value})
+      | `ENone region ->
+           let value = {
+             lpar = Region.ghost;
+             inside = {
+               c_None   = region;
+               colon    = Region.ghost;
+               opt_type = var_type};
+             rpar = Region.ghost}
+           in ConstrExpr (NoneExpr {region; value}) in
     let value = {
       kwd_var    = $1;
       name       = $2;
       colon      = $3;
-      var_type   = $4;
+      var_type;
-      ass        = $5;
+      assign     = $6;
-      init       = $6;
+      init;
-      terminator = $7}
+      terminator = $8}
     in {region; value}
   }
 
 extended_expr:
-  expr              { }
+  expr              { {region = expr_to_region $1;
-| LBRACKET RBRACKET { }
+                       value  = `Expr $1} }
-| C_None            { }
+| LBRACKET RBRACKET { {region = cover $1 $2;
- *)
+                       value  = `EList ($1,$2)} }
+| C_None            { {region = $1; value = `ENone $1} }
+
+var_decl_type_expr:
+  var_decl_cartesian { Prod   $1 }
+| sum_type           { Sum    $1 }
+| record_type        { Record $1 }
+
+var_decl_cartesian:
+  nsepseq(var_decl_core_type,TIMES) {
+    let region = nsepseq_to_region type_expr_to_region $1
+    in {region; value=$1}
+  }
+
+var_decl_core_type:
+  type_name      { TAlias  $1 }
+| par(type_expr) { ParType $1 }
+
 instruction:
   single_instr { Single $1 }
 | block        { Block  $1 }

Tests/crowdfunding.ligo

@@ -10,7 +10,7 @@ entrypoint contribute (storage store : state;
                        const sender  : address;
                        const amount  : mutez)
   : state * list (operation) is
-  var operations : list (operation) := ([] : list (operation)) // TODO
+  var operations : list (operation) := []
   begin
     if now > store.deadline then
       fail "Deadline passed"
@@ -26,9 +26,9 @@ entrypoint contribute (storage store : state;
       end
   end with (store, operations)
 
-entrypoint get_funds (storage store : state; const sender : address)
+entrypoint withdraw (storage store : state; const sender : address)
   : state * list (operation) is
-  var operations : list (operation) := ([] : list (operation)) // TODO
+  var operations : list (operation) := []
   begin
     if sender = owner then
       if now >= store.deadline then
@@ -44,7 +44,7 @@ entrypoint get_funds (storage store : state; const sender : address)
 
 entrypoint claim (storage store : state; const sender : address)
   : state * list (operation) is
-  var operations : list (operation) := ([] : list (operation)) // TODO
+  var operations : list (operation) := []
   var amount : mutez := 0
   begin
     if now <= store.deadline then