Do notation changes

changelog.md

@@ -16,6 +16,11 @@
 - Implicit conversions for `const` behave correctly now, meaning that code like `const SOMECONST = 0.int; procThatTakesInt32(SOMECONST)` will be illegal now.
   Simply write `const SOMECONST = 0` instead.
 
+- A bug that automatically lifts nodes of kind `stmtList` into lambda
+  expressions has been fixed.
+
+- Code blocks that start with a `do` are now consistent of type
+  `nkDo`.
 
 ## Library additions
 

compiler/ast.nim

@@ -1052,7 +1052,7 @@ template `[]`*(n: Indexable, i: BackwardsIndex): Indexable = n[n.len - i.int]
 template `[]=`*(n: Indexable, i: BackwardsIndex; x: Indexable) = n[n.len - i.int] = x
 
 when defined(useNodeIds):
-  const nodeIdToDebug* = -1 # 2322968
+  const nodeIdToDebug* = -1
   var gNodeId: int
 
 proc newNode*(kind: TNodeKind): PNode =

compiler/options.nim

@@ -146,6 +146,11 @@ type
       ## Allows to modify a NimNode where the type has already been
       ## flagged with nfSem. If you actually do this, it will cause
       ## bugs.
+    optOldDoNode
+      ## Do blocks without arguments magically become nkStmtList;
+      ## Nodes of kind nkStmtList automatically convert to lambda
+      ## expressions without arguments.
+
 
   SymbolFilesOption* = enum
     disabledSf, writeOnlySf, readOnlySf, v2Sf

compiler/parser.nim

@@ -1090,9 +1090,6 @@ proc parseParamList(p: var TParser, retColon = true): PNode =
     getTok(p)
     optInd(p, result)
     result.sons[0] = parseTypeDesc(p)
-  elif not retColon and not hasParLe:
-    # Mark as "not there" in order to mark for deprecation in the semantic pass:
-    result = p.emptyNode
   when defined(nimpretty):
     dec p.em.doIndentMore
     dec p.em.keepIndents
@@ -1108,10 +1105,13 @@ proc parseDoBlock(p: var TParser; info: TLineInfo): PNode =
   let params = parseParamList(p, retColon=false)
   let pragmas = optPragmas(p)
   colcom(p, result)
-  result = parseStmt(p)
-  if params.kind != nkEmpty:
+  let body = parseStmt(p)
+  let legacyMode = optOldDoNode in p.lex.config.legacyFeatures
+  if legacyMode and params.len == 1 and params[0].kind == nkEmpty:
+    result = body
+  else:
     result = newProcNode(nkDo, info,
-      body = result, params = params, name = p.emptyNode, pattern = p.emptyNode,
+      body = body, params = params, name = p.emptyNode, pattern = p.emptyNode,
       genericParams = p.emptyNode, pragmas = pragmas, exceptions = p.emptyNode)
 
 proc parseProcExpr(p: var TParser; isExpr: bool; kind: TNodeKind): PNode =
@@ -1351,14 +1351,17 @@ proc postExprBlocks(p: var TParser, x: PNode): PNode =
   result = x
   if p.tok.indent >= 0: return
 
-  var
-    openingParams = p.emptyNode
-    openingPragmas = p.emptyNode
+  var openingParams, openingPragmas: PNode
 
-  if p.tok.tokType == tkDo:
+  let doToken = p.tok.tokType == tkDo
+  if doToken:
     getTok(p)
     openingParams = parseParamList(p, retColon=false)
     openingPragmas = optPragmas(p)
+  else:
+    openingParams = newNodeP(nkFormalParams, p)
+    openingParams.add p.emptyNode
+    openingPragmas = p.emptyNode
 
   if p.tok.tokType == tkColon:
     result = makeCall(result)
@@ -1371,7 +1374,12 @@ proc postExprBlocks(p: var TParser, x: PNode): PNode =
       if stmtList[0].kind == nkStmtList: stmtList = stmtList[0]
 
       stmtList.flags.incl nfBlockArg
-      if openingParams.kind != nkEmpty:
+      let legacyMode = optOldDoNode in p.lex.config.legacyFeatures
+      if (legacyMode and openingParams.len > 1) or (not(legacyMode) and doToken):
+        # in legacy mode, a nkDo node is generated depending on the
+        # amount of parameters of the do node `do(a,b,c): ...` vs
+        # `do:`. This has changed, without legacy mode an `nkDo` node
+        # is generated always when also a doToken got parsed.
         result.add newProcNode(nkDo, stmtList.info, body = stmtList,
                                params = openingParams,
                                name = p.emptyNode, pattern = p.emptyNode,
@@ -1413,7 +1421,7 @@ proc postExprBlocks(p: var TParser, x: PNode): PNode =
 
       if nextBlock.kind == nkElse: break
   else:
-    if openingParams.kind != nkEmpty:
+    if openingParams.len > 1:
       parMessage(p, "expected ':'")
 
 proc parseExprStmt(p: var TParser): PNode =

compiler/semexprs.nim

@@ -1994,7 +1994,8 @@ proc semQuoteAst(c: PContext, n: PNode): PNode =
     ids = newSeq[PNode](1)
       # this will store the generated param names
       # leave some room for the result symbol
-
+  if quotedBlock.kind == nkDo:
+    quotedBlock = quotedBlock[^1]
   if quotedBlock.kind != nkStmtList:
     localError(c.config, n.info, errXExpected, "block")
 

compiler/sigmatch.nim

@@ -1964,9 +1964,10 @@ proc incMatches(m: var TCandidate; r: TTypeRelation; convMatch = 1) =
   of isEqual: inc(m.exactMatches)
   of isNone: discard
 
-template matchesVoidProc(t: PType): bool =
+proc matchesVoidProc(t: PType): bool =
+  # used onley for legacy optOldDoProc.
   (t.kind == tyProc and t.len == 1 and t.sons[0] == nil) or
-    (t.kind == tyBuiltInTypeClass and t.sons[0].kind == tyProc)
+  (t.kind == tyBuiltInTypeClass and t.sons[0].kind == tyProc)
 
 proc paramTypesMatchAux(m: var TCandidate, f, a: PType,
                         argSemantized, argOrig: PNode): PNode =
@@ -2122,8 +2123,8 @@ proc paramTypesMatchAux(m: var TCandidate, f, a: PType,
       inc(m.genericMatches)
       m.fauxMatch = a.kind
       return arg
-    elif a.kind == tyVoid and f.matchesVoidProc and argOrig.kind == nkStmtList:
-      # lift do blocks without params to lambdas
+    elif optOldDoNode in c.config.legacyFeatures and a.kind == tyVoid and f.matchesVoidProc and argOrig.kind == nkStmtList:
+      # lift stmtList nodes to lambdas.
       let p = c.graph
       let lifted = c.semExpr(c, newProcNode(nkDo, argOrig.info, body = argOrig,
           params = nkFormalParams.newTree(p.emptyNode), name = p.emptyNode, pattern = p.emptyNode,

lib/core/macros.nim

@@ -1630,6 +1630,18 @@ proc getProjectPath*(): string = discard
   ## be confused with ``system.currentSourcePath`` which returns
   ## the path of the current module.
 
+macro stripDoNode*(arg: untyped): untyped =
+  ## for templates that expect multiple blocks of code with the do
+  ## notation, this macro will strip the do lambda node to inline the
+  ## body.
+  if arg.kind == nnkDo:
+    expectLen(arg[3], 1)
+    expectKind(arg[3][0], nnkEmpty)
+    result = arg[6]
+  else:
+    result = arg
+
+
 when defined(nimMacrosSizealignof):
   proc getSize*(arg: NimNode): int {.magic: "NSizeOf", noSideEffect.} =
     ## Returns the same result as ``system.sizeof`` if the size is

lib/pure/asyncdispatch.nim

@@ -1191,7 +1191,7 @@ else:
     var curList: seq[Callback]
 
     let selector = getGlobalDispatcher().selector
-    withData(selector, fd.int, fdData):
+    withData(selector, fd.int, fdData) do:
       case event
       of Event.Read:
         shallowCopy(curList, fdData.readList)

lib/pure/collections/sharedtables.nim

@@ -80,7 +80,7 @@ template withValue*[A, B](t: var SharedTable[A, B], key: A,
     let hasKey = index >= 0
     if hasKey:
       var value {.inject.} = addr(t.data[index].val)
-      body
+      stripDoNode(body)
   finally:
     release(t.lock)
 
@@ -107,9 +107,9 @@ template withValue*[A, B](t: var SharedTable[A, B], key: A,
     let hasKey = index >= 0
     if hasKey:
       var value {.inject.} = addr(t.data[index].val)
-      body1
+      stripDoNode(body1)
     else:
-      body2
+      stripDoNode(body2)
   finally:
     release(t.lock)
 

lib/pure/collections/tables.nim

@@ -217,7 +217,7 @@
 ## * `hashes module<hashes.html>`_ for helper functions for hashing
 
 
-import hashes, math, algorithm
+import hashes, math, algorithm, macros
 
 include "system/inclrtl"
 
@@ -610,7 +610,7 @@ template withValue*[A, B](t: var Table[A, B], key: A, value, body: untyped) =
   let hasKey = index >= 0
   if hasKey:
     var value {.inject.} = addr(t.data[index].val)
-    body
+    stripDoNode(body)
 
 template withValue*[A, B](t: var Table[A, B], key: A,
                           value, body1, body2: untyped) =
@@ -634,9 +634,9 @@ template withValue*[A, B](t: var Table[A, B], key: A,
   let hasKey = index >= 0
   if hasKey:
     var value {.inject.} = addr(t.data[index].val)
-    body1
+    stripDoNode(body1)
   else:
-    body2
+    stripDoNode(body2)
 
 
 iterator pairs*[A, B](t: Table[A, B]): (A, B) =

lib/pure/ioselects/ioselectors_epoll.nim

@@ -9,7 +9,7 @@
 
 # This module implements Linux epoll().
 
-import posix, times, epoll
+import posix, times, epoll, macros
 
 # Maximum number of events that can be returned
 const MAX_EPOLL_EVENTS = 64
@@ -519,7 +519,7 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value,
   s.checkFd(fdi)
   if fdi in s:
     var value = addr(s.getData(fdi))
-    body
+    stripDoNode(body)
 
 template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1,
                         body2: untyped) =
@@ -528,9 +528,9 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1,
   s.checkFd(fdi)
   if fdi in s:
     var value = addr(s.getData(fdi))
-    body1
+    stripDoNode(body1)
   else:
-    body2
+    stripDoNode(body2)
 
 proc getFd*[T](s: Selector[T]): int =
   return s.epollFd.int

lib/pure/ioselects/ioselectors_kqueue.nim

@@ -9,7 +9,7 @@
 
 #  This module implements BSD kqueue().
 
-import posix, times, kqueue
+import posix, times, kqueue, macros
 
 const
   # Maximum number of events that can be returned.
@@ -617,7 +617,7 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value,
   s.checkFd(fdi)
   if fdi in s:
     var value = addr(s.getData(fdi))
-    body
+    stripDoNode(body)
 
 template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1,
                       body2: untyped) =
@@ -626,9 +626,9 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1,
   s.checkFd(fdi)
   if fdi in s:
     var value = addr(s.getData(fdi))
-    body1
+    stripDoNode(body1)
   else:
-    body2
+    stripDoNode(body2)
 
 
 proc getFd*[T](s: Selector[T]): int =

lib/pure/ioselects/ioselectors_poll.nim

@@ -9,7 +9,7 @@
 
 # This module implements Posix poll().
 
-import posix, times
+import posix, times, macros
 
 # Maximum number of events that can be returned
 const MAX_POLL_EVENTS = 64
@@ -292,7 +292,7 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value,
   s.checkFd(fdi)
   if fdi in s:
     var value = addr(s.getData(fdi))
-    body
+    stripDoNode(body)
 
 template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1,
                         body2: untyped) =
@@ -301,10 +301,9 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value, body1,
   s.checkFd(fdi)
   if fdi in s:
     var value = addr(s.getData(fdi))
-    body1
+    stripDoNode(body1)
   else:
-    body2
-
+    stripDoNode(body2)
 
 proc getFd*[T](s: Selector[T]): int =
   return -1

lib/pure/ioselects/ioselectors_select.nim

@@ -9,7 +9,7 @@
 
 # This module implements Posix and Windows select().
 
-import times, nativesockets
+import times, nativesockets, macros
 
 when defined(windows):
   import winlean
@@ -440,7 +440,7 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value,
         break
       inc(i)
     if i != FD_SETSIZE:
-      body
+      stripDoNode(body)
 
 template withData*[T](s: Selector[T], fd: SocketHandle|int, value,
                       body1, body2: untyped) =
@@ -456,10 +456,9 @@ template withData*[T](s: Selector[T], fd: SocketHandle|int, value,
           break
         inc(i)
       if i != FD_SETSIZE:
-        body1
+        stripDoNode(body1)
       else:
-        body2
-
+        stripDoNode(body2)
 
 proc getFd*[T](s: Selector[T]): int =
   return -1

tests/closure/tclosure.nim

@@ -453,7 +453,7 @@ block doNotation:
   b.onClick do (e: Event):
     echo "click at ", e.x, ",", e.y
 
-  b.onFocusLost:
+  b.onFocusLost do:
     echo "lost focus 1"
 
   b.onFocusLost do:
@@ -462,10 +462,10 @@ block doNotation:
   b.onUserEvent("UserEvent 1") do:
     discard
 
-  b.onUserEvent "UserEvent 2":
+  b.onUserEvent("UserEvent 2") do:
     discard
 
-  b.onUserEvent("UserEvent 3"):
+  b.onUserEvent("UserEvent 3") do:
     discard
 
   b.onUserEvent("UserEvent 4", () => echo "event 4")

tests/closure/tclosure_issues.nim

@@ -67,16 +67,18 @@ proc foo(): proc =
 echo foo()()
 
 
+# issue #7104
+
 block tissue7104:
   proc sp(cb: proc())=
-      cb()
+    cb()
 
-  sp:
-      var i = 0
+  sp do:
+    var i = 0
+    echo "ok ", i
+    sp do:
+      inc i
       echo "ok ", i
-      sp():
-          inc i
-          echo "ok ", i
-          sp do:
-              inc i
-              echo "ok ", i
+      sp do:
+        inc i
+        echo "ok ", i

tests/misc/tlambdadonotation.nim

@@ -29,7 +29,7 @@ proc foo(x: proc {.closure.}) =
 proc bar =
   var x = 123
   # foo proc = echo x     #[ ok ]#
-  foo: echo x             #[ SIGSEGV: Illegal storage access. (Attempt to read from nil?) ]#
+  foo do: echo x             #[ SIGSEGV: Illegal storage access. (Attempt to read from nil?) ]#
 
 bar()