nimpretty: implement a --maxLineLen command line option

(cherry picked from commit 5bf3734984)

compiler/layouter.nim

@@ -15,7 +15,6 @@ from os import changeFileExt
 from sequtils import delete
 
 const
-  MaxLineLen = 80
   MinLineLen = 15
 
 type
@@ -50,6 +49,7 @@ type
     indentStack: seq[int]
     fixedUntil: int # marks where we must not go in the content
     altSplitPos: array[SplitKind, int] # alternative split positions
+    maxLineLen*: int
 
 proc openEmitter*(em: var Emitter, cache: IdentCache;
                   config: ConfigRef, fileIdx: FileIndex) =
@@ -77,7 +77,7 @@ proc computeMax(em: Emitter; pos: int): int =
     var foundTab = false
     while p < em.tokens.len and em.kinds[p] != ltEndSection:
       if em.kinds[p] in {ltCrucialNewline, ltSplittingNewline}:
-        if foundTab and lineLen <= MaxLineLen:
+        if foundTab and lineLen <= em.maxLineLen:
           result = max(result, lhs + extraSpace)
         inc p
         break
@@ -124,7 +124,7 @@ proc optionalIsGood(em: var Emitter; pos, currentLen: int): bool =
   em.findNewline(p, lineLen)
   if p == pos+1: # optionalNewline followed by another newline
     result = false
-  elif em.kinds[p-1] == ltComment and currentLen+lineLen < MaxLineLen+MinLineLen:
+  elif em.kinds[p-1] == ltComment and currentLen+lineLen < em.maxLineLen+MinLineLen:
     result = false
   elif p+1 < em.tokens.len and em.kinds[p+1] == ltSpaces and
       em.kinds[p-1] == ltOptionalNewline:
@@ -183,7 +183,7 @@ proc closeEmitter*(em: var Emitter) =
       else:
         # pick the shorter indentation token:
         var spaces = maxLhs - lineLen
-        if spaces < em.tokens[i].len or computeRhs(em, i+1)+maxLhs <= MaxLineLen+MinLineLen:
+        if spaces < em.tokens[i].len or computeRhs(em, i+1)+maxLhs <= em.maxLineLen+MinLineLen:
           if spaces <= 0 and content[^1] notin {' ', '\L'}: spaces = 1
           for j in 1..spaces: content.add ' '
           inc lineLen, spaces
@@ -196,7 +196,7 @@ proc closeEmitter*(em: var Emitter) =
       lineBegin = i+1
     of ltOptionalNewline:
       let totalLineLen = lineLen + lenOfNextTokens(em, i)
-      if totalLineLen > MaxLineLen and optionalIsGood(em, i, lineLen):
+      if totalLineLen > em.maxLineLen and optionalIsGood(em, i, lineLen):
         if i-1 >= 0 and em.kinds[i-1] == ltSpaces:
           let spaces = em.tokens[i-1].len
           content.setLen(content.len - spaces)
@@ -298,7 +298,7 @@ const
   oprSet = {tkOpr, tkDiv, tkMod, tkShl, tkShr, tkIn, tkNotin, tkIs,
             tkIsnot, tkNot, tkOf, tkAs, tkDotDot, tkAnd, tkOr, tkXor}
 
-template goodCol(col): bool = col >= MaxLineLen div 2
+template goodCol(col): bool = col >= em.maxLineLen div 2
 
 template moreIndent(em): int =
   if em.doIndentMore > 0: em.indWidth*2 else: em.indWidth

nimpretty/nimpretty.nim

@@ -18,7 +18,7 @@ import ../compiler / [idents, msgs, ast, syntaxes, renderer, options,
 import parseopt, strutils, os
 
 const
-  Version = "0.1"
+  Version = "0.2"
   Usage = "nimpretty - Nim Pretty Printer Version " & Version & """
 
   (c) 2017 Andreas Rumpf
@@ -28,6 +28,7 @@ Options:
   --output:file         set the output file (default: overwrite the input file)
   --indent:N[=0]        set the number of spaces that is used for indentation
                         --indent:0 means autodetection (default behaviour)
+  --maxLineLen:N        set the desired maximum line length (default: 80)
   --version             show the version
   --help                show this help
 """
@@ -45,6 +46,7 @@ proc writeVersion() =
 type
   PrettyOptions = object
     indWidth: int
+    maxLineLen: int
 
 proc prettyPrint(infile, outfile: string, opt: PrettyOptions) =
   var conf = newConfigRef()
@@ -55,6 +57,7 @@ proc prettyPrint(infile, outfile: string, opt: PrettyOptions) =
   var p: TParsers
   p.parser.em.indWidth = opt.indWidth
   if setupParsers(p, fileIdx, newIdentCache(), conf):
+    p.parser.em.maxLineLen = opt.maxLineLen
     discard parseAll(p)
     closeParsers(p)
 
@@ -66,6 +69,7 @@ proc main =
     # if input is not actually over-written, when nimpretty is a noop).
     # --backup was un-documented (rely on git instead).
   var opt: PrettyOptions
+  opt.maxLineLen = 80
   for kind, key, val in getopt():
     case kind
     of cmdArgument:
@@ -77,6 +81,7 @@ proc main =
       of "backup": backup = parseBool(val)
       of "output", "o": outfile = val
       of "indent": opt.indWidth = parseInt(val)
+      of "maxlinelen": opt.maxLineLen = parseInt(val)
       else: writeHelp()
     of cmdEnd: assert(false) # cannot happen
   if infile.len == 0: