improved setTagUri

* renamed setTagUriForType to setTagUri
 * generated TagId is now const (can be used in case etc)
 * Uses compile-time counter independent from tag library

doc/index.txt

@@ -238,8 +238,8 @@ Defining a custom tag uri for a type
     level, experience: int32
     drops: seq[string]
   
-  setTagUriForType(Mob, "!Mob")
-  setTagUriForType(seq[string], "!Drops")
+  setTagUri(Mob, "!Mob")
+  setTagUri(seq[string], "!Drops")
   
   var mob = Mob(level: 42, experience: 1800, drops:
       @["Sword of Mob Slaying"])
@@ -352,8 +352,7 @@ Processing a Sequence of Heterogeneous Items
   type Person = object
     name: string
 
-  setTagUriForType(Person, "!nim:demo:Person",
-                   yTagPerson)
+  setTagUri(Person, "!nim:demo:Person", yTagPerson)
 
   var
     s = newFileStream("in.yaml", fmRead)
@@ -367,7 +366,7 @@ Processing a Sequence of Heterogeneous Items
   while nextEvent.kind != yamlEndSeq:
     var curTag = nextEvent.tag()
     if curTag == yTagQuestionMark:
-      # we only support implicitly tagged scalar events
+      # we only support implicitly tagged scalars
       assert nextEvent.kind == yamlScalar
       case guessType(nextEvent.scalarContent)
       of yTypeInteger: curTag = yTagInteger
@@ -390,14 +389,11 @@ Processing a Sequence of Heterogeneous Items
       var b: bool
       events.constructChild(context, b)
       echo "got boolean: ", b
-    else:
-      # non-standard tag ids are not available
-      # at compile time
-      if curTag == yTagPerson:
-        var p: Person
-        events.constructChild(context, p)
-        echo "got Person with name: ", p.name
-      else: assert false, "unsupported tag: " & $curTag
+    of yTagPerson:
+      var p: Person
+      events.constructChild(context, p)
+      echo "got Person with name: ", p.name
+    else: assert false, "unsupported tag: " & $curTag
     nextEvent = events.peek()
   assert events.next().kind == yamlEndSeq
   assert events.next().kind == yamlEndDoc

doc/serialization.txt

@@ -142,13 +142,13 @@ These tags are generated on the fly based on the types you instantiate
 ``Table`` or ``seq`` with.
 
 You may customize the tags used for your types by using the template
-`setTagUriForType <yaml.html#setTagUriForType.t,typedesc,string>`_. It may not
+`setTagUri <yaml.html#setTagUri.t,typedesc,string>`_. It may not
 be applied to scalar and collection types implemented by NimYAML, but you can
 for example use it on a certain ``seq`` type:
 
 .. code-block:: nim
 
-    setTagUriForType(seq[string], "!nim:my:seq")
+    setTagUri(seq[string], "!nim:my:seq")
 
 Customize Serialization
 =======================

test/serializing.nim

@@ -30,9 +30,9 @@ type
 proc `$`(v: BetterInt): string {.borrow.}
 proc `==`(l, r: BetterInt): bool {.borrow.}
 
-setTagUriForType(TrafficLight, "!tl")
-setTagUriForType(Node, "!example.net:Node")
-setTagUriForType(BetterInt, "!test:BetterInt")
+setTagUri(TrafficLight, "!tl")
+setTagUri(Node, "!example.net:Node")
+setTagUri(BetterInt, "!test:BetterInt")
 
 proc representObject*(value: BetterInt, ts: TagStyle = tsNone,
     c: SerializationContext, tag: TagId): RawYamlStream {.raises: [].} =

yaml.nim

@@ -633,31 +633,40 @@ var
     ## Should not be modified manually. Will be extended by
     ## `serializable <#serializable,stmt,stmt>`_.
 
-static:
-  var
-    registeredUris {.compileTime.} = newSeq[string]() ## \
-      ## Since Table doesn't really work at compile time, we also store 
-      ## registered URIs here to be able to generate a static compiler error 
-      ## when the user tries to register an URI more than once.
+var
+  nextStaticTagId {.compileTime.} = 100.TagId ## \
+    ## used for generating unique TagIds with ``setTagUri``.
+  registeredUris {.compileTime.} = newSeq[string]() ## \
+    ## Since Table doesn't really work at compile time, we also store 
+    ## registered URIs here to be able to generate a static compiler error 
+    ## when the user tries to register an URI more than once.
 
-template setTagUriForType*(t: typedesc, uri: string): stmt =
+template setTagUri*(t: typedesc, uri: string): stmt =
   ## Associate the given uri with a certain type. This uri is used as YAML tag
   ## when loading and dumping values of this type.
   when uri in registeredUris:
     {. fatal: "[NimYAML] URI \"" & uri & "\" registered twice!" .}
-  static: registeredUris.add(uri)
-  let id {.gensym.} = serializationTagLibrary.registerUri(uri)
+  const id {.genSym.} = nextStaticTagId
+  static:
+    registeredUris.add(uri)
+    nextStaticTagId = TagId(int(nextStaticTagId) + 1)
+  when nextStaticTagId == yFirstCustomTagId:
+    {.fatal: "Too many tags!".}
+  serializationTagLibrary.tags[uri] = id
   proc yamlTag*(T: typedesc[t]): TagId {.inline, raises: [].} = id
     ## autogenerated
 
-template setTagUriForType*(t: typedesc, uri: string, idName: expr): stmt =
-  ## Like `setTagUriForType <#setTagUriForType,typedesc,string>`_, but lets
+template setTagUri*(t: typedesc, uri: string, idName: expr): stmt =
+  ## Like `setTagUri <#setTagUri.t,typedesc,string>`_, but lets
   ## you choose a symbol for the `TagId <#TagId>`_ of the uri. This is only
   ## necessary if you want to implement serialization / construction yourself.
   when uri in registeredUris:
     {. fatal: "[NimYAML] URI \"" & uri & "\" registered twice!" .}
-  static: registeredUris.add(uri)
-  let idName* = serializationTagLibrary.registerUri(uri)
+  const idName* = nextStaticTagId
+  static:
+    registeredUris.add(uri)
+    nextStaticTagId = TagId(int(nextStaticTagId) + 1)
+  serializationTagLibrary.tags[uri] = idName
   proc yamlTag*(T: typedesc[t]): TagId {.inline, raises: [].} = idName
     ## autogenerated
 
@@ -678,17 +687,17 @@ static:
   registeredUris.add("!nim:nil:seq")
 
 # tags for Nim's standard types
-setTagUriForType(char, "!nim:system:char", yTagNimChar)
-setTagUriForType(int8, "!nim:system:int8", yTagNimInt8)
-setTagUriForType(int16, "!nim:system:int16", yTagNimInt16)
-setTagUriForType(int32, "!nim:system:int32", yTagNimInt32)
-setTagUriForType(int64, "!nim:system:int64", yTagNimInt64)
-setTagUriForType(uint8, "!nim:system:uint8", yTagNimUInt8)
-setTagUriForType(uint16, "!nim:system:uint16", yTagNimUInt16)
-setTagUriForType(uint32, "!nim:system:uint32", yTagNimUInt32)
-setTagUriForType(uint64, "!nim:system:uint64", yTagNimUInt64)
-setTagUriForType(float32, "!nim:system:float32", yTagNimFloat32)
-setTagUriForType(float64, "!nim:system:float64", yTagNimFloat64)
+setTagUri(char, "!nim:system:char", yTagNimChar)
+setTagUri(int8, "!nim:system:int8", yTagNimInt8)
+setTagUri(int16, "!nim:system:int16", yTagNimInt16)
+setTagUri(int32, "!nim:system:int32", yTagNimInt32)
+setTagUri(int64, "!nim:system:int64", yTagNimInt64)
+setTagUri(uint8, "!nim:system:uint8", yTagNimUInt8)
+setTagUri(uint16, "!nim:system:uint16", yTagNimUInt16)
+setTagUri(uint32, "!nim:system:uint32", yTagNimUInt32)
+setTagUri(uint64, "!nim:system:uint64", yTagNimUInt64)
+setTagUri(float32, "!nim:system:float32", yTagNimFloat32)
+setTagUri(float64, "!nim:system:float64", yTagNimFloat64)
 
 # implementation