From 6b96122453fda22dc44a581af1d536988c1adf41 Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Wed, 19 Apr 2023 06:45:56 -0600
Subject: fix(iter): add tag to packed table

If pack() is called with a single value, it does not create a table; it
simply returns the value it is passed. When unpack is called with a
table argument, it interprets that table as a list of values that were
packed together into a table.

This causes a problem when the single value being packed is _itself_ a
table. pack() will not place it into another table, but unpack() sees
the table argument and tries to unpack it.

To fix this, we add a simple "tag" to packed table values so that
unpack() only attempts to unpack tables that have this tag. Other tables
are left alone. The tag is simply the length of the table.
---
 test/functional/lua/vim_spec.lua | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'test/functional')

diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index e5caf6f6f7..07b0f0340a 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -3381,6 +3381,33 @@ describe('lua stdlib', function()
         end
       end)
       eq({ A = 2, C = 6 }, it:totable())
+
+    it('handles table values mid-pipeline', function()
+      local map = {
+        item = {
+          file = 'test',
+        },
+        item_2 = {
+          file = 'test',
+        },
+        item_3 = {
+          file = 'test',
+        },
+      }
+
+      local output = vim.iter(map):map(function(key, value)
+        return { [key] = value.file }
+      end):totable()
+
+      table.sort(output, function(a, b)
+        return next(a) < next(b)
+      end)
+
+      eq({
+        { item = 'test' },
+        { item_2 = 'test' },
+        { item_3 = 'test' },
+      }, output)
     end)
   end)
 end)
-- 
cgit 


From 94894068794dbb99804cda689b6c37e70376c8ca Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Wed, 19 Apr 2023 07:05:04 -0600
Subject: fix(iter): remove special case totable for map-like tables

This was originally meant as a convenience but prevents possible
functionality. For example:

  -- Get the keys of the table with even values
  local t = { a = 1, b = 2, c = 3, d = 4 }
  vim.iter(t):map(function(k, v)
    if v % 2 == 0 then return k end
  end):totable()

The example above would not work, because the map() function returns
only a single value, and cannot be converted back into a table (there
are many such examples like this).

Instead, to convert an iterator into a map-like table, users can use
fold():

  vim.iter(t):fold({}, function(t, k, v)
    t[k] = v
    return t
  end)
---
 test/functional/lua/vim_spec.lua | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

(limited to 'test/functional')

diff --git a/test/functional/lua/vim_spec.lua b/test/functional/lua/vim_spec.lua
index 07b0f0340a..e37d477376 100644
--- a/test/functional/lua/vim_spec.lua
+++ b/test/functional/lua/vim_spec.lua
@@ -3374,13 +3374,18 @@ describe('lua stdlib', function()
     end)
 
     it('handles map-like tables', function()
-      local t = { a = 1, b = 2, c = 3 }
-      local it = vim.iter(t):map(function(k, v)
+      local it = vim.iter({ a = 1, b = 2, c = 3 }):map(function(k, v)
         if v % 2 ~= 0 then
           return k:upper(), v * 2
         end
       end)
-      eq({ A = 2, C = 6 }, it:totable())
+
+      local t = it:fold({}, function(t, k, v)
+        t[k] = v
+        return t
+      end)
+      eq({ A = 2, C = 6 }, t)
+    end)
 
     it('handles table values mid-pipeline', function()
       local map = {
-- 
cgit