Implemented diff algorithm for ropes and added basic formatter integr…

…ation

config/settings.json

@@ -151,6 +151,7 @@
         },
         "nim": {
             "treesitter": "alaviss/tree-sitter-nim",
+            "formatter": "nph",
             "tabWidth": 2,
             "indent": "spaces",
             "indentAfter": [
@@ -528,6 +529,12 @@
         "maxViews": 2
     },
 
+    "text": {
+        "reload-diff": true,
+        "reload-diff-timeout": 250,
+        "format-on-save": false,
+    },
+
     "debugger": {
         "type": {
             "lldb-dap": {

config/settings.schema.json

@@ -96,6 +96,30 @@
                             "type": "string",
                             "description": "Subdirectory of the repository which contains the queries. By default the queries are found by searching for highlights.scm"
                         },
+                        "formatter": {
+                            "oneOf": [
+                                {
+                                    "type": "string",
+                                    "description": "Path of the formatter executable"
+                                },
+                                {
+                                    "type": "object",
+                                    "properties": {
+                                        "path": {
+                                            "type": "string",
+                                            "description": "Path of the formatter executable"
+                                        },
+                                        "args": {
+                                            "type": "array",
+                                            "items": {
+                                                "type": "string"
+                                            },
+                                            "description": "Arguments passed to the formatter"
+                                        }
+                                    }
+                                }
+                            ],
+                        },
                         "tabWidth": {
                             "type": "integer"
                         },
@@ -207,6 +231,35 @@
             "additionalProperties": false
         },
 
+        "^\\+?text$": {
+            "type": "object",
+            "properties": {
+                "reload-diff": {
+                    "type": "boolean",
+                    "description": "When set then the editor will, when reloading a file, calculate the diff between the content on disk and in memory, and apply the diff to update the in memory representation match the on disk representation.\nThis will reduce memory usage over time, but increase memory usage quite a bit while diffing.\nThe diffing has a timeout of 'text.reload-diff-timeout'. When this timeout is reached then diffing will be aborted and the file content will be loaded normally."
+                },
+                "reload-diff-timeout": {
+                    "type": "integer",
+                    "description": "Timeout in milliseconds for diffing when reloading files from disk."
+                },
+                "format-on-save": {
+                    "type": "boolean",
+                    "description": "When set the editor will run the specified formatter when saving. See 'languages.*.formatter'"
+                },
+                "^\\+?whitespace$": {
+                    "type": "object",
+                    "properties": {
+                        "char": {
+                            "type": "string"
+                        }
+                    }
+                },
+                "highlight-treesitter-errors": {
+                    "type": "boolean"
+                }
+            }
+        },
+
         "^\\+?editor$": {
             "type": "object",
             "properties": {

src/misc/rope_utils.nim

@@ -1,8 +1,9 @@
-import std/[options, strutils]
+import std/[options, strutils, atomics]
 import nimsumtree/[rope, sumtree]
 import scripting_api except DocumentEditor, TextDocumentEditor, AstDocumentEditor
 from scripting_api as api import nil
 import custom_async, custom_unicode, util
+import text/diff
 
 {.push gcsafe.}
 {.push raises: [].}
@@ -38,6 +39,61 @@ proc createRopeAsync*(str: ptr string, rope: ptr Rope): Future[Option[int]] {.as
     return errorIndex.some
   return int.none
 
+type DiffRopesData = object
+  rc: Atomic[int]
+  a: Rope
+  b: Rope
+  diff: ptr RopeDiff[int]
+  cancel: Atomic[bool]
+  threadDone: Atomic[bool]
+
+proc diffRopeThread(data: ptr DiffRopesData) =
+  defer:
+    if data[].rc.fetchSub(1, moRelease) == 1:
+      fence(moAcquire)
+      try:
+        `=destroy`(data[])
+        `=wasMoved`(data[])
+      except:
+        discard
+      freeShared(data)
+
+  discard data[].rc.fetchAdd(1, moRelaxed)
+
+  var a = data.a.clone()
+  var b = data.b.clone()
+  var d = diff(a, b, data.cancel.addr)
+  if not data.cancel.load:
+    data.diff[] = d.ensureMove
+  data.threadDone.store(true)
+
+proc diffRopeAsync*(a, b: sink Rope, res: ptr RopeDiff[int]): Future[void] {.async.} =
+  ## Returns `some(index)` if the string contains invalid utf8 at `index`
+  let data = createShared(DiffRopesData)
+  data.rc.store(1)
+  data.a = a.clone()
+  data.b = b.clone()
+  data.diff = res
+  data.cancel.store(false)
+  data.threadDone.store(false)
+
+  defer:
+    if data[].rc.fetchSub(1, moRelease) == 1:
+      fence(moAcquire)
+      try:
+        {.gcsafe.}:
+          `=destroy`(data[])
+          `=wasMoved`(data[])
+      except:
+        discard
+      freeShared(data)
+
+  try:
+    await spawnAsync(diffRopeThread, data)
+  except CancelledError as e:
+    data.cancel.store(true)
+    raise e
+
 ######################################################################### Rope api only, maybe move to rope library later
 
 func toCharsInLine*[D](self: Rope, position: D): Count =