[bugfix] fix nim-lang#11469, new rules for a newline in nimpretty

compiler/layouter.nim

@@ -25,7 +25,7 @@ type
     detectSemicolonKind, useSemicolon, dontTouch
 
   LayoutToken = enum
-    ltSpaces, ltNewline, ltTab,
+    ltSpaces, ltNewline, ltTab, ltOptionalNewline,
     ltComment, ltLit, ltKeyword, ltExportMarker, ltIdent,
     ltOther, ltOpr,
     ltBeginSection, ltEndSection
@@ -88,14 +88,38 @@ proc computeRhs(em: Emitter; pos: int): int =
     inc result, em.tokens[p].len
     inc p
 
+proc optionalIsGood(em: Emitter; pos: int): bool =
+  let ourIndent = em.tokens[pos].len
+  var p = pos+1
+  var lineLen = 0
+  while p < em.tokens.len and em.kinds[p] != ltNewline:
+    inc lineLen, em.tokens[p].len
+    inc p
+  if p+1 < em.tokens.len and em.kinds[p+1] == ltSpaces and
+      em.tokens[p-1] == "," and
+      em.tokens[p+1].len != ourIndent:
+    result = false
+  elif em.kinds[pos+1] == ltOther: # note: pos+1, not p+1
+    result = false
+  else:
+    result = lineLen > 10 and p > pos + 3
+
+proc lenOfNextTokens(em: Emitter; pos: int, n = 3): int =
+  result = 0
+  for i in 1 .. n:
+    if pos+i < em.tokens.len:
+      if em.kinds[pos+i] == ltNewline: break
+      inc result, em.tokens[pos+i].len
+
 proc closeEmitter*(em: var Emitter) =
   let outFile = em.config.absOutFile
 
   var content = newStringOfCap(16_000)
   var maxLhs = 0
   var lineLen = 0
   var lineBegin = 0
-  for i in 0..em.tokens.high:
+  var i = 0
+  while i <= em.tokens.high:
     case em.kinds[i]
     of ltBeginSection:
       maxLhs = computeMax(em, lineBegin)
@@ -113,9 +137,22 @@ proc closeEmitter*(em: var Emitter) =
       content.add em.tokens[i]
       lineLen = 0
       lineBegin = i+1
+    of ltOptionalNewline:
+      if lineLen + lenOfNextTokens(em, i) >= MaxLineLen and optionalIsGood(em, i):
+        if i-1 >= 0 and em.kinds[i-1] == ltSpaces:
+          let spaces = em.tokens[i-1].len
+          content.setLen(content.len - spaces)
+        content.add "\L"
+        content.add em.tokens[i]
+        lineLen = em.tokens[i].len
+        lineBegin = i+1
+        if i+1 < em.kinds.len and em.kinds[i+1] == ltSpaces:
+          # inhibit extra spaces at the start of a new line
+          inc i
     else:
       content.add em.tokens[i]
       inc lineLen, em.tokens[i].len
+    inc i
 
   if fileExists(outFile) and readFile(outFile.string) == content:
     discard "do nothing, see #9499"
@@ -199,31 +236,29 @@ proc softLinebreak(em: var Emitter, lit: string) =
     if em.lastTok in splitters:
       # bug #10295, check first if even more indentation would help:
       let spaces = em.indentLevel+moreIndent(em)
-      if spaces < em.col:
-        removeSpaces em
-        wrNewline(em)
-        em.col = 0
-        wrSpaces em, spaces
+      if spaces < em.col and spaces > 0:
+        wr(em, strutils.repeat(' ', spaces), ltOptionalNewline)
     else:
       # search backwards for a good split position:
       for a in mitems(em.altSplitPos):
         if a > em.fixedUntil:
-          var spaces = 0
-          while a+spaces < em.kinds.len and em.kinds[a+spaces] == ltSpaces:
-            inc spaces
-          if spaces > 0:
-            delete(em.tokens, a, a+spaces-1)
-            delete(em.kinds, a, a+spaces-1)
-          em.kinds.insert(ltNewline, a)
-          em.tokens.insert("\L", a)
-          em.kinds.insert(ltSpaces, a+1)
+          when false:
+            var spaces = 0
+            while a+spaces < em.kinds.len and em.kinds[a+spaces] in {ltSpaces, ltOptionalNewline}:
+              inc spaces
+            if spaces > 0:
+              delete(em.tokens, a, a+spaces-1)
+              delete(em.kinds, a, a+spaces-1)
+
+          em.kinds.insert(ltOptionalNewline, a+1)
           em.tokens.insert(repeat(' ', em.indentLevel+moreIndent(em)), a+1)
-          # recompute em.col:
-          var i = em.kinds.len-1
-          em.col = 0
-          while i >= 0 and em.kinds[i] != ltNewline:
-            inc em.col, em.tokens[i].len
-            dec i
+          when false:
+            # recompute em.col:
+            var i = em.kinds.len-1
+            em.col = 0
+            while i >= 0 and em.kinds[i] != ltNewline:
+              inc em.col, em.tokens[i].len
+              dec i
           # mark position as "already split here"
           a = -1
           break

compiler/parser.nim

@@ -904,6 +904,7 @@ proc parsePragma(p: var TParser): PNode =
   result = newNodeP(nkPragma, p)
   inc p.inPragma
   when defined(nimpretty):
+    inc p.em.doIndentMore
     inc p.em.keepIndents
   getTok(p)
   optInd(p, result)
@@ -924,6 +925,7 @@ proc parsePragma(p: var TParser): PNode =
     parMessage(p, "expected '.}'")
   dec p.inPragma
   when defined(nimpretty):
+    dec p.em.doIndentMore
     dec p.em.keepIndents
 
 proc identVis(p: var TParser; allowDot=false): PNode =

nimpretty/tests/expected/exhaustive.nim

@@ -15,8 +15,7 @@ let expr = if true: "true" else: "false"
 
 var body = newNimNode(nnkIfExpr).add(
   newNimNode(nnkElifBranch).add(
-    infix(newDotExpr(ident("a"), ident("kind")), "==", newDotExpr(ident("b"),
-        ident("kind"))),
+    infix(newDotExpr(ident("a"), ident("kind")), "==", newDotExpr(ident("b"), ident("kind"))),
     condition
   ),
   newNimNode(nnkElse).add(newStmtList(newNimNode(nnkReturnStmt).add(ident(
@@ -125,8 +124,8 @@ type
     fixedUntil: int # marks where we must not go in the content
     altSplitPos: array[SplitKind, int] # alternative split positions
 
-proc openEmitter*[T, S](em: var Emitter; config: ConfigRef;
-    fileIdx: FileIndex) {.pragmaHereWrongCurlyEnd.} =
+proc openEmitter*[T, S](em: var Emitter; config: ConfigRef; fileIdx: FileIndex) {.
+    pragmaHereWrongCurlyEnd.} =
   let outfile = changeFileExt(config.toFullPath(fileIdx), ".pretty.nim")
   em.f = llStreamOpen(outfile, fmWrite)
   em.config = config
@@ -200,8 +199,7 @@ proc emitTok*(em: var Emitter; L: TLexer; tok: TToken) =
     if em.lineSpan > 0: calcCol(em, lit)
     if not endsInWhite(em):
       wr(" ")
-      if em.lineSpan == 0 and max(em.col,
-          LineCommentColumn) + lit.len <= MaxLineLen:
+      if em.lineSpan == 0 and max(em.col, LineCommentColumn) + lit.len <= MaxLineLen:
         for i in 1 .. LineCommentColumn - em.col: wr(" ")
     wr lit
 
@@ -219,8 +217,7 @@ proc emitTok*(em: var Emitter; L: TLexer; tok: TToken) =
       "case returns value"
 
 
-  if tok.tokType == tkComment and tok.line == em.lastLineNumber and
-      tok.indent >= 0:
+  if tok.tokType == tkComment and tok.line == em.lastLineNumber and tok.indent >= 0:
     # we have an inline comment so handle it before the indentation token:
     emitComment(em, tok)
     preventComment = true
@@ -289,8 +286,7 @@ proc emitTok*(em: var Emitter; L: TLexer; tok: TToken) =
       tkGTripleStrLit, tkCharLit:
     let lit = fileSection(em.config, em.fid, tok.offsetA, tok.offsetB)
     softLinebreak(em, lit)
-    if endsInAlpha(em) and tok.tokType notin {tkGStrLit, tkGTripleStrLit}: wr(
-        " ")
+    if endsInAlpha(em) and tok.tokType notin {tkGStrLit, tkGTripleStrLit}: wr(" ")
     em.lineSpan = countNewlines(lit)
     if em.lineSpan > 0: calcCol(em, lit)
     wr lit
@@ -383,8 +379,7 @@ import osproc
 let res = execProcess(
     "echo | openssl s_client -connect example.com:443 2>/dev/null | openssl x509 -noout -dates")
 
-let res = execProcess(
-    "echo | openssl s_client -connect example.com:443 2>/dev/null | openssl x509 -noout -dates")
+let res = execProcess("echo | openssl s_client -connect example.com:443 2>/dev/null | openssl x509 -noout -dates")
 
 
 # bug #10177

nimpretty/tests/expected/simple3.nim

@@ -8,9 +8,8 @@ foo bar
 proc fun() =
   echo "ok1"
 
-proc fun2(a = "fooo" & "bar" & "bar" & "bar" & "bar" & (
-    "bar" & "bar" & "bar") & "bar" & "bar" & "bar" & "bar" & "bar" & "bar" &
-    "bar" & "bar" & "bar"): auto =
+proc fun2(a = "fooo" & "bar" & "bar" & "bar" & "bar" & ("bar" & "bar" & "bar") &
+    "bar" & "bar" & "bar" & "bar" & "bar" & "bar" & "bar" & "bar" & "bar"): auto =
   discard
 
 fun2()