Improve parsing of empty nulls and lists of objects

samples/hie.lua

@@ -0,0 +1,120 @@
+return {
+  ["cradle"] = {
+    ["multi"] = {
+      [1] = {
+        ["path"] = "./bazel-bin",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [2] = {
+        ["path"] = "./bazel-out",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [3] = {
+        ["path"] = "./bazel-testlogs",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [4] = {
+        ["path"] = "./bazel-yesod-bridge",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [5] = {
+        ["path"] = "./bazel-hls-bin",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [6] = {
+        ["path"] = "./bazel-hls-out",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [7] = {
+        ["path"] = "./bazel-hls-testlogs",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [8] = {
+        ["path"] = "./bazel-hls-yesod-bridge",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      },
+      [9] = {
+        ["path"] = "./bridge-site",
+        ["config"] = {
+          ["cradle"] = {
+            ["bios"] = {
+              ["program"] = "./bridge-site/.hie-bios"
+            }
+          }
+        }
+      },
+      [10] = {
+        ["path"] = "./cassandra-util",
+        ["config"] = {
+          ["cradle"] = {
+            ["bios"] = {
+              ["program"] = "./cassandra-util/.hie-bios"
+            }
+          }
+        }
+      },
+      [11] = {
+        ["path"] = "./conduit-util",
+        ["config"] = {
+          ["cradle"] = {
+            ["bios"] = {
+              ["program"] = "./conduit-util/.hie-bios"
+            }
+          }
+        }
+      },
+      [12] = {
+        ["path"] = "./hsx-util",
+        ["config"] = {
+          ["cradle"] = {
+            ["bios"] = {
+              ["program"] = "./hsx-util/.hie-bios"
+            }
+          }
+        }
+      },
+      [13] = {
+        ["path"] = "./page",
+        ["config"] = {
+          ["cradle"] = {
+            ["bios"] = {
+              ["program"] = "./page/.hie-bios"
+            }
+          }
+        }
+      },
+      [14] = {
+        ["path"] = "./wai-practice",
+        ["config"] = {
+          ["cradle"] = {
+            ["bios"] = {
+              ["program"] = "./wai-practice/.hie-bios"
+            }
+          }
+        }
+      },
+      [15] = {
+        ["path"] = "./",
+        ["config"] = {
+          ["cradle"] = {}
+        }
+      }
+    }
+  }
+}

samples/hie.yaml

@@ -0,0 +1,68 @@
+cradle:
+  multi:
+    - path: "./bazel-bin"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-out"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-testlogs"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-yesod-bridge"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-hls-bin"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-hls-out"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-hls-testlogs"
+      config:
+        cradle:
+          none:
+    - path: "./bazel-hls-yesod-bridge"
+      config:
+        cradle:
+          none:
+    - path: "./bridge-site"
+      config:
+        cradle:
+          bios:
+            program: "./bridge-site/.hie-bios"
+    - path: "./cassandra-util"
+      config:
+        cradle:
+          bios:
+            program: "./cassandra-util/.hie-bios"
+    - path: "./conduit-util"
+      config:
+        cradle:
+          bios:
+            program: "./conduit-util/.hie-bios"
+    - path: "./hsx-util"
+      config:
+        cradle:
+          bios:
+            program: "./hsx-util/.hie-bios"
+    - path: "./page"
+      config:
+        cradle:
+          bios:
+            program: "./page/.hie-bios"
+    - path: "./wai-practice"
+      config:
+        cradle:
+          bios:
+            program: "./wai-practice/.hie-bios"
+    - path: "./"
+      config:
+        cradle:
+          none:

samples/null.lua

@@ -1,4 +1,17 @@
 return {
+  ["empties"] = {
+    [1] = {},
+    [2] = {
+      ["nonEmptyInitial"] = 7,
+      ["nonEmptyFinal"] = 8,
+    },
+    [3] = {
+      ["nonEmptyFinal"] = 9,
+    },
+    [4] = {
+      ["nonEmptyInitial"] = 10,
+    }
+  },
   ["end"] = "test passed?",
   ["notnull"] = true,
   ["test"] = "A test for null values"

samples/null.yaml

@@ -3,6 +3,16 @@
   thisis: null
   thistoo: NULL
   notnull: yes
+  empties:
+  - emptySolo:
+  - nonEmptyInitial: 7
+    emptyCentral:
+    nonEmptyFinal: 8
+  - emptyInitial:
+    nonEmptyFinal: 9
+  - nonEmptyInitial: 10
+    emptyFinal:
+  - emptyTerminal:
   tildeis: ~
   capitalized: Null
   end: test passed?

yaml.lua

@@ -336,6 +336,10 @@ Parser.parse = function (self)
   elseif c.token.const == true then
     self:advanceValue();
     result = c.token.value
+  -- handle the case where a label is followed by a dedent and should parse as
+  -- null
+  elseif c.token[1] == "dedent" then
+    result = nil
   else
     error("ParseError: unexpected token '" .. c.token[1] .. "'" .. context(c.token.input))
   end
@@ -465,32 +469,109 @@ Parser.parseTextBlock = function (self, sep)
   return result
 end
 
-Parser.parseHash = function (self, hash)
+-- @param hash table|nil Table to populate with labels
+-- @param listHash boolean True if this is a hash that occurs at the
+-- start of a list
+-- @return the fully parsed hash
+Parser.parseHash = function (self, hash, listHash)
   hash = hash or {}
   local indents = 0
+  local acceptedImpliedIndent = false
 
   if self:isInline() then
     local id = self:advanceValue()
-    self:expect(":", "expected semi-colon after id")
+    self:expect(":", "expected colon after id")
     self:ignoreSpace()
-    if self:accept("indent") then
+    if not listHash and self:accept("indent") then
       indents = indents + 1
       hash[id] = self:parse()
-    else
+    elseif not listHash then
       hash[id] = self:parse()
       if self:accept("indent") then
         indents = indents + 1
       end
+    else -- listHash == true
+      -- If there is another identifier *without* an indent, we have a case something like this:
+      --[[
+        listof:
+        - nonNullValue: 7
+        - nullValue:
+        scalarValue:
+      --]]
+      if self:peekType("id") then
+        hash[id] = nil
+        return
+      -- If the next token is another list item at the same indent level, then
+      -- parse this value as null.
+      --[[
+         listof:
+         - nullValue:
+         - nonNullValue: 7
+      --]]
+      elseif listHash and self:peekType("-") then
+        hash[id] = nil
+        return hash
+      -- if the next token is a single indent level and then an identifier
+      -- parse this key as null.
+      --[[
+        listof:
+        - nullValue:
+          nonNullValue: 7
+      --]]
+      elseif listHash and self:peekType("indent") and self:peekType("id", 2) then
+        self:advance()
+        acceptedImpliedIndent = true
+        indents = indents + 1
+        hash[id] = nil
+      -- if the next token is a single indent level and then something other
+      -- than an identifier, consume the indent, and then parse recursively.
+      -- Handles these cases among others
+      --[[
+        listof:
+        - nonNullValue:
+            subKey: 7
+      --]]
+      --[[
+        listof:
+        - keyedSubList:
+          - listItem: 1
+      --]]
+      elseif listHash and self:peekType("indent") then
+        self:advance()
+        acceptedImpliedIndent = true
+        indents = indents + 1
+        hash[id] = self:parse()
+        self:ignoreSpace();
+      -- if the next token is not an indent, and is not one of the above cases
+      -- we likely have something on the same line like this:
+      --[[
+        value: 7
+      --]]
+      else
+        hash[id] = self:parse()
+        self:ignoreSpace();
+      end
     end
-    self:ignoreSpace();
+  end
+
+  -- Consume the implied indent if it wasn't already consumed above.
+  if listHash and not acceptedImpliedIndent and self:peekType("indent") then
+    self:advance()
+    indents = indents + 1
   end
 
   while self:peekType("id") do
     local id = self:advanceValue()
-    self:expect(":","expected semi-colon after id")
+    self:expect(":","expected colon after id")
     self:ignoreSpace()
-    hash[id] = self:parse()
-    self:ignoreSpace();
+    -- If the next token is another id at the same indent level, this key should
+    -- parse as null.
+    if self:peekType("id") then
+      hash[id] = nil
+    else
+      hash[id] = self:parse()
+      self:ignoreSpace();
+    end
   end
 
   while indents > 0 do
@@ -533,7 +614,13 @@ Parser.parseList = function (self)
   local list = {}
   while self:accept("-") do
     self:ignoreSpace()
-    list[#list + 1] = self:parse()
+    -- Check for the case of a hash starting as a list item, and pass that on
+    -- to the parseHash function directly.
+    if self:peekType("id") then
+      list[#list + 1] = self:parseHash({}, true)
+    else
+      list[#list + 1] = self:parse()
+    end
 
     self:ignoreSpace()
   end