refactors initSrcGen and initTokRender into returning objects (#22421)

2 files changed, 36 insertions, 61 deletions

diff --git a/compiler/docgen.nim b/compiler/docgen.nim
index 4a0ae6fc9..6a78d8693 100644
--- a/compiler/docgen.nim
+++ b/compiler/docgen.nim
@@ -492,9 +492,8 @@ proc externalDep(d: PDoc; module: PSym): string =
 proc nodeToHighlightedHtml(d: PDoc; n: PNode; result: var string;
                            renderFlags: TRenderFlags = {};
                            procLink: string) =
-  var r: TSrcGen = TSrcGen()
+  var r: TSrcGen = initTokRender(n, renderFlags)
   var literal = ""
-  initTokRender(r, n, renderFlags)
   var kind = tkEof
   var tokenPos = 0
   var procTokenPos = 0
@@ -1030,8 +1029,7 @@ proc toLangSymbol(k: TSymKind, n: PNode, baseName: string): LangSymbol =
         genNode = n[miscPos][1]   # FIXME: what is index 1?
     if genNode != nil:
       var literal = ""
-      var r: TSrcGen
-      initTokRender(r, genNode, {renderNoBody, renderNoComments,
+      var r: TSrcGen = initTokRender(genNode, {renderNoBody, renderNoComments,
         renderNoPragmas, renderNoProcDefs, renderExpandUsing})
       var kind = tkEof
       while true:
@@ -1058,9 +1056,8 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind, docFlags: DocFlags, nonEx
   else:
     comm.add genRecComment(d, n)
 
-  var r: TSrcGen
   # Obtain the plain rendered string for hyperlink titles.
-  initTokRender(r, n, {renderNoBody, renderNoComments, renderDocComments,
+  var r: TSrcGen = initTokRender(n, {renderNoBody, renderNoComments, renderDocComments,
     renderNoPragmas, renderNoProcDefs, renderExpandUsing})
   while true:
     getNextTok(r, kind, literal)
@@ -1164,11 +1161,11 @@ proc genJsonItem(d: PDoc, n, nameNode: PNode, k: TSymKind, nonExports = false):
   var
     name = getNameEsc(d, nameNode)
     comm = genRecComment(d, n)
-    r: TSrcGen = default(TSrcGen)
+    r: TSrcGen
     renderFlags = {renderNoBody, renderNoComments, renderDocComments, renderExpandUsing}
   if nonExports:
     renderFlags.incl renderNonExportedFields
-  initTokRender(r, n, renderFlags)
+  r = initTokRender(n, renderFlags)
   result.json = %{ "name": %name, "type": %($k), "line": %n.info.line.int,
                    "col": %n.info.col}
   if comm != nil:
diff --git a/compiler/renderer.nim b/compiler/renderer.nim
index 2af8d8326..e39be78fe 100644
--- a/compiler/renderer.nim
+++ b/compiler/renderer.nim
@@ -145,19 +145,13 @@ const
   MaxLineLen = 80
   LineCommentColumn = 30
 
-proc initSrcGen(g: var TSrcGen, renderFlags: TRenderFlags; config: ConfigRef) =
-  g.comStack = @[]
-  g.tokens = @[]
-  g.indent = 0
-  g.lineLen = 0
-  g.pos = 0
-  g.idx = 0
-  g.buf = ""
-  g.flags = renderFlags
-  g.pendingNL = -1
-  g.pendingWhitespace = -1
-  g.inside = {}
-  g.config = config
+proc initSrcGen(renderFlags: TRenderFlags; config: ConfigRef): TSrcGen =
+  result = TSrcGen(comStack: @[], tokens: @[], indent: 0,
+                   lineLen: 0, pos: 0, idx: 0, buf: "",
+                   flags: renderFlags, pendingNL: -1,
+                   pendingWhitespace: -1, inside: {},
+                   config: config
+                   )
 
 proc addTok(g: var TSrcGen, kind: TokType, s: string; sym: PSym = nil) =
   g.tokens.add TRenderTok(kind: kind, length: int16(s.len), sym: sym)
@@ -630,14 +624,12 @@ type
 const
   emptyContext: TContext = (spacing: 0, flags: {})
 
-proc initContext(c: var TContext) =
-  c.spacing = 0
-  c.flags = {}
+proc initContext(): TContext =
+  result = (spacing: 0, flags: {})
 
 proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false)
 proc gsub(g: var TSrcGen, n: PNode, fromStmtList = false) =
-  var c: TContext = default(TContext)
-  initContext(c)
+  var c: TContext = initContext()
   gsub(g, n, c, fromStmtList = fromStmtList)
 
 proc hasCom(n: PNode): bool =
@@ -767,9 +759,8 @@ proc gcond(g: var TSrcGen, n: PNode) =
     put(g, tkParRi, ")")
 
 proc gif(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   gcond(g, n[0][0])
-  initContext(c)
   putWithSpace(g, tkColon, ":")
   if longMode(g, n) or (lsub(g, n[0][1]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
@@ -780,20 +771,18 @@ proc gif(g: var TSrcGen, n: PNode) =
     gsub(g, n[i], c)
 
 proc gwhile(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   putWithSpace(g, tkWhile, "while")
   gcond(g, n[0])
   putWithSpace(g, tkColon, ":")
-  initContext(c)
   if longMode(g, n) or (lsub(g, n[1]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
   gstmts(g, n[1], c)
 
 proc gpattern(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   put(g, tkCurlyLe, "{")
-  initContext(c)
   if longMode(g, n) or (lsub(g, n[0]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
@@ -801,20 +790,18 @@ proc gpattern(g: var TSrcGen, n: PNode) =
   put(g, tkCurlyRi, "}")
 
 proc gpragmaBlock(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   gsub(g, n[0])
   putWithSpace(g, tkColon, ":")
-  initContext(c)
   if longMode(g, n) or (lsub(g, n[1]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
   gstmts(g, n[1], c)
 
 proc gtry(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   put(g, tkTry, "try")
   putWithSpace(g, tkColon, ":")
-  initContext(c)
   if longMode(g, n) or (lsub(g, n[0]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
@@ -822,9 +809,8 @@ proc gtry(g: var TSrcGen, n: PNode) =
   gsons(g, n, c, 1)
 
 proc gfor(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   putWithSpace(g, tkFor, "for")
-  initContext(c)
   if longMode(g, n) or
       (lsub(g, n[^1]) + lsub(g, n[^2]) + 6 + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
@@ -837,8 +823,7 @@ proc gfor(g: var TSrcGen, n: PNode) =
   gstmts(g, n[^1], c)
 
 proc gcase(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
-  initContext(c)
+  var c: TContext = initContext()
   if n.len == 0: return
   var last = if n[^1].kind == nkElse: -2 else: -1
   if longMode(g, n, 0, last): incl(c.flags, rfLongMode)
@@ -848,7 +833,7 @@ proc gcase(g: var TSrcGen, n: PNode) =
   optNL(g)
   gsons(g, n, c, 1, last)
   if last == - 2:
-    initContext(c)
+    c = initContext()
     if longMode(g, n[^1]): incl(c.flags, rfLongMode)
     gsub(g, n[^1], c)
 
@@ -858,7 +843,7 @@ proc genSymSuffix(result: var string, s: PSym) {.inline.} =
     result.addInt s.id
 
 proc gproc(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   if n[namePos].kind == nkSym:
     let s = n[namePos].sym
     var ret = renderDefinitionName(s)
@@ -885,7 +870,7 @@ proc gproc(g: var TSrcGen, n: PNode) =
       indentNL(g)
       gcoms(g)
       dedent(g)
-      initContext(c)
+      c = initContext()
       gstmts(g, n[bodyPos], c)
       putNL(g)
     else:
@@ -894,8 +879,7 @@ proc gproc(g: var TSrcGen, n: PNode) =
       dedent(g)
 
 proc gTypeClassTy(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
-  initContext(c)
+  var c: TContext = initContext()
   putWithSpace(g, tkConcept, "concept")
   gsons(g, n[0], c) # arglist
   gsub(g, n[1]) # pragmas
@@ -914,8 +898,7 @@ proc gblock(g: var TSrcGen, n: PNode) =
   if n.len == 0:
     return
 
-  var c: TContext = default(TContext)
-  initContext(c)
+  var c: TContext = initContext()
 
   if n[0].kind != nkEmpty:
     putWithSpace(g, tkBlock, "block")
@@ -935,10 +918,9 @@ proc gblock(g: var TSrcGen, n: PNode) =
   gstmts(g, n[1], c)
 
 proc gstaticStmt(g: var TSrcGen, n: PNode) =
-  var c: TContext = default(TContext)
+  var c: TContext = initContext()
   putWithSpace(g, tkStatic, "static")
   putWithSpace(g, tkColon, ":")
-  initContext(c)
   if longMode(g, n) or (lsub(g, n[0]) + g.lineLen > MaxLineLen):
     incl(c.flags, rfLongMode)
   gcoms(g)                    # a good place for comments
@@ -1631,7 +1613,7 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
   of nkTypeSection:
     gsection(g, n, emptyContext, tkType, "type")
   of nkConstSection:
-    initContext(a)
+    a = initContext()
     incl(a.flags, rfInConstExpr)
     gsection(g, n, a, tkConst, "const")
   of nkVarSection, nkLetSection, nkUsingStmt:
@@ -1799,13 +1781,11 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
     gsub(g, n, 0)
     put(g, tkParRi, ")")
   of nkGotoState:
-    var c: TContext = default(TContext)
-    initContext c
+    var c: TContext = initContext()
     putWithSpace g, tkSymbol, "goto"
     gsons(g, n, c)
   of nkState:
-    var c: TContext = default(TContext)
-    initContext c
+    var c: TContext = initContext()
     putWithSpace g, tkSymbol, "state"
     gsub(g, n[0], c)
     putWithSpace(g, tkColon, ":")
@@ -1829,8 +1809,7 @@ proc gsub(g: var TSrcGen, n: PNode, c: TContext, fromStmtList = false) =
 
 proc renderTree*(n: PNode, renderFlags: TRenderFlags = {}): string =
   if n == nil: return "<nil tree>"
-  var g: TSrcGen = default(TSrcGen)
-  initSrcGen(g, renderFlags, newPartialConfigRef())
+  var g: TSrcGen = initSrcGen(renderFlags, newPartialConfigRef())
   # do not indent the initial statement list so that
   # writeFile("file.nim", repr n)
   # produces working Nim code:
@@ -1848,8 +1827,7 @@ proc renderModule*(n: PNode, outfile: string,
                    conf: ConfigRef = nil) =
   var
     f: File = default(File)
-    g: TSrcGen
-  initSrcGen(g, renderFlags, conf)
+    g: TSrcGen = initSrcGen(renderFlags, conf)
   g.fid = fid
   for i in 0..<n.len:
     gsub(g, n[i])
@@ -1865,9 +1843,9 @@ proc renderModule*(n: PNode, outfile: string,
   else:
     rawMessage(g.config, errGenerated, "cannot open file: " & outfile)
 
-proc initTokRender*(r: var TSrcGen, n: PNode, renderFlags: TRenderFlags = {}) =
-  initSrcGen(r, renderFlags, newPartialConfigRef())
-  gsub(r, n)
+proc initTokRender*(n: PNode, renderFlags: TRenderFlags = {}): TSrcGen =
+  result = initSrcGen(renderFlags, newPartialConfigRef())
+  gsub(result, n)
 
 proc getNextTok*(r: var TSrcGen, kind: var TokType, literal: var string) =
   if r.idx < r.tokens.len: