Merge pull request #40 from iwanders/fix-losing-values-on-mixed-key-t…

…ables

Prevent losing entries with mixed key tables

lib/lyaml/init.lua

@@ -199,9 +199,24 @@ local dumper_mt = {
  elseif itsa == 'string' or itsa == 'boolean' or itsa == 'number' then
  return self:dump_scalar(node)
  elseif itsa == 'table' then
- if #node > 0 then
+ -- Something is only a sequence if its keys start at 1
+ -- and are consecutive integers without any jumps.
+ local prior_key = 0
+ local is_pure_sequence = true
+ local i, v = next(node, nil)
+ while i and is_pure_sequence do
+ if type(i) ~= "number" or (prior_key + 1 ~= i) then
+ is_pure_sequence = false -- breaks the loop
+ else
+ prior_key = i
+ i, v = next(node, prior_key)
+ end
+ end
+ if is_pure_sequence then
+ -- Only sequentially numbered integer keys starting from 1.
  return self:dump_sequence(node)
  else
+ -- Table contains non sequential integer keys or mixed keys.
  return self:dump_mapping(node)
  end
  else -- unsupported Lua type

spec/lib_lyaml_spec.yaml

@@ -55,6 +55,21 @@ specify lyaml:
  - it writes a mapping: |
  expect (lyaml.dump {{a=1, b=2, c=3, d=""}}).
  to_contain.all_of {"a: 1", "b: 2", "c: 3", "d: ''"}
+ - it writes a mapping of mixed keys: |
+ expect (lyaml.dump {{[1]=1, [2]=2, three="three", four="4", [5]="five"}}).
+ to_contain.all_of {"1: 1", "2: 2", "three: three", "four: '4'", "5: five"}
+ - it writes a mapping of integer keys starting at two: |
+ expect (lyaml.dump {{[2]=2, [3]=3, [4]=4}}).
+ to_contain.all_of {"2: 2", "3: 3", "4: 4"}
+ - it writes a mapping of mixed keys starting at one: |
+ expect (lyaml.dump {{[1]=1, [2]=2, [3]=3, foo="bar"}}).
+ to_contain.all_of {"1: 1", "2: 2", "3: 3", "foo: bar"}
+ - it writes a mapping of mixed keys starting at two: |
+ expect (lyaml.dump {{[2]=2, [3]=3, [4]=4, foo="bar"}}).
+ to_contain.all_of {"2: 2", "3: 3", "4: 4", "foo: bar"}
+ - it writes a table containing nils (jumps in index) as mapping: |
+ expect (lyaml.dump {{1, 2, nil, 3, 4}}).
+ to_contain.all_of {"1: 1", "2: 2", "4: 3", "5: 4"}
 
  - context anchors and aliases:
  - before: