Initial ideas around a related-to special property.

src/pitpkg/cliconstants.nim

@@ -181,6 +181,30 @@ Issue Properties:
           after 12 hours
           every 2 weeks, 10a544
 
+    relations
+
+      Used to store information about relationships between issues. PIT treats
+      all relations as bi-directional and will update related tickets as
+      necessary to maintain the integrity of the links.
+
+      Relations are captured as <relation-type> <related-issue-id>. Multiple
+      relations can be separated by ",". The <related-issue-id> must be a unique
+      issue ID or ID prefix (in the case of multiple matching issues, the first
+      found will be used with no guarantee on ordering). Valid value pairs for
+      <relation-type> are:
+
+        - child-of / parent-of
+        - related-to (default)
+        - blocks / blocked-by
+        - follows / precedes
+        - caused / caused-by
+
+      Examples:
+
+          relation: child-of fb3e63, blocked-by 2b71c1
+          relation: 2b71c1, 8f2b4c, follows 184dc6
+          relation: relates-to 2b71c1
+
     tags
 
       If present, expected to be a comma-delimited list of text tags. The -g

src/pitpkg/private/libpit.nim

@@ -11,6 +11,7 @@ type
     filepath*: string
     summary*, details*: string
     properties*: TableRef[string, string]
+    relations*: seq[Relation]
     tags*: seq[string]
     state*: IssueState
 
@@ -40,6 +41,19 @@ type
     interval*: TimeInterval
     isFromCompletion*: bool
 
+  Relation* = tuple[rel: RelationType, id: UUID]
+
+  RelationType* = enum
+    ParentOf = "parent-of",
+    ChildOf = "child-of",
+    RelatedTo = "related-to",
+    Blocks = "blocks",
+    BlockedBy = "blocked-by",
+    Follow = "follows",
+    FollowedBy = "followed-by",
+    Caused = "caused",
+    CausedBy = "caused-by"
+
 const DONE_FOLDER_FORMAT* = "yyyy-MM"
 const ISO8601_MS = "yyyy-MM-dd'T'HH:mm:ss'.'fffzzz"
 
@@ -173,6 +187,11 @@ proc parseDate*(d: string): DateTime =
       continue
   raise newException(ValueError, "Unable to parse input as a date: " & d & errMsg)
 
+proc parseRelation*(relStr: string): Relation =
+  let parts = relStr.split({' '})
+  if parts.len == 1: result = (RelatedTo, parseUUID(parts[0]))
+  else: result = (parseEnum[RelationType](parts[0]), parseUUID(parts[1]))
+
 ## Parse and format issues
 proc fromStorageFormat*(id: string, issueTxt: string): Issue =
   type ParseState = enum ReadingSummary, ReadingProps, ReadingDetails
@@ -180,6 +199,7 @@ proc fromStorageFormat*(id: string, issueTxt: string): Issue =
   result = Issue(
     id: parseUUID(id),
     properties: newTable[string,string](),
+    relations: @[],
     tags: @[])
 
   var parseState = ReadingSummary
@@ -203,14 +223,16 @@ proc fromStorageFormat*(id: string, issueTxt: string): Issue =
         parseState = ReadingDetails
         continue
 
-
       let parts = line.split({':'}, 1) --> map(it.strip())
       if parts.len != 2:
         raise newException(ValueError, "unable to parse property line: " & line)
 
-      # Take care of special properties: `tags`
+      # Take care of special properties: `tags` and `relations`
       if parts[0] == "tags":
         result.tags = parts[1].split({','}) --> map(it.strip())
+      elif parts[0] == "relations":
+        result.relations = parts[1].split({','}) -->
+          map(parseRelation(it.strip))
       else: result[parts[0]] = parts[1]
 
     of ReadingDetails:
@@ -231,6 +253,11 @@ proc toStorageFormat*(issue: Issue, withComments = false): string =
 
   if issue.tags.len > 0: lines.add("tags: " & issue.tags.join(","))
 
+  if issue.relations.len > 0:
+    lines.add("relations: " &
+      (issue.relations --> map(it.rel & " " & it.id)).
+      join(', '))
+
   if not isEmptyOrWhitespace(issue.details) or withComments:
     if withComments: lines.add("# Details go below the \"--------\"")
     lines.add("--------")