From 11751d8718cf55ee84744262a6dd165d32adfb19 Mon Sep 17 00:00:00 2001
From: Timothee Cour <timothee.cour2@gmail.com>
Date: Mon, 15 Mar 2021 13:14:13 -0700
Subject: [PATCH] implement --spellsuggest with 0 arguments

---
 compiler/commands.nim         |  5 ++--
 compiler/lookups.nim          |  5 +++-
 compiler/options.nim          |  1 +
 doc/advopt.txt                |  4 +++-
 tests/misc/tspellsuggest.nim  |  2 +-
 tests/misc/tspellsuggest2.nim | 45 +++++++++++++++++++++++++++++++++++
 6 files changed, 57 insertions(+), 5 deletions(-)
 create mode 100644 tests/misc/tspellsuggest2.nim

diff --git a/compiler/commands.nim b/compiler/commands.nim
index eefaa35cb2ae..f36a4f515606 100644
--- a/compiler/commands.nim
+++ b/compiler/commands.nim
@@ -864,8 +864,9 @@ proc processSwitch*(switch, arg: string, pass: TCmdLinePass, info: TLineInfo;
   of "listfullpaths":
     processOnOffSwitchG(conf, {optListFullPaths}, arg, pass, info)
   of "spellsuggest":
-    expectArg(conf, switch, arg, pass, info)
-    conf.spellSuggestMax = parseInt(arg)
+    if arg.len == 0: conf.spellSuggestMax = spellSuggestSecretSauce
+    elif arg == "auto": conf.spellSuggestMax = spellSuggestSecretSauce
+    else: conf.spellSuggestMax = parseInt(arg)
   of "declaredlocs":
     processOnOffSwitchG(conf, {optDeclaredLocs}, arg, pass, info)
   of "dynliboverride":
diff --git a/compiler/lookups.nim b/compiler/lookups.nim
index 2cca964bfe36..ee446dc34a38 100644
--- a/compiler/lookups.nim
+++ b/compiler/lookups.nim
@@ -403,8 +403,11 @@ proc fixSpelling(c: PContext, n: PNode, ident: PIdent, result: var string) =
   var count = 0
   while true:
     # pending https://github.com/timotheecour/Nim/issues/373 use more efficient `itemsSorted`.
-    if count >= c.config.spellSuggestMax or list.len == 0: break
+    if list.len == 0: break
     let e = list.pop()
+    if c.config.spellSuggestMax == spellSuggestSecretSauce:
+      if e.dist > e0.dist: break
+    elif count >= c.config.spellSuggestMax: break
     if count == 0:
       result.add "\ncandidate misspellings (edit distance, lexical scope distance): "
     result.add "\n ($1, $2): '$3'" % [$e.dist, $e.depth, e.sym.name.s]
diff --git a/compiler/options.nim b/compiler/options.nim
index 55cb58e7fb5d..6aa7533f7668 100644
--- a/compiler/options.nim
+++ b/compiler/options.nim
@@ -576,6 +576,7 @@ const
   htmldocsDir* = htmldocsDirname.RelativeDir
   docRootDefault* = "@default" # using `@` instead of `$` to avoid shell quoting complications
   oKeepVariableNames* = true
+  spellSuggestSecretSauce* = -1
 
 proc mainCommandArg*(conf: ConfigRef): string =
   ## This is intended for commands like check or parse
diff --git a/doc/advopt.txt b/doc/advopt.txt
index db36596c5a5c..e31fbd834dc5 100644
--- a/doc/advopt.txt
+++ b/doc/advopt.txt
@@ -35,7 +35,9 @@ Advanced options:
   --colors:on|off           turn compiler messages coloring on|off
   --listFullPaths:on|off    list full paths in messages
   --declaredLocs:on|off     show declaration locations in messages
-  --spellSuggest:num        show at most `num` spelling suggestions on typos
+  --spellSuggest|:num       show at most `num >=0` spelling suggestions on typos.
+                            if `num` is not specified (or `auto`), return
+                            an implementation defined set of suggestions.
   -w:on|off|list, --warnings:on|off|list
                             turn all warnings on|off or list all available
   --warning[X]:on|off       turn specific warning X on|off
diff --git a/tests/misc/tspellsuggest.nim b/tests/misc/tspellsuggest.nim
index 4b93e76c89da..938be34607f3 100644
--- a/tests/misc/tspellsuggest.nim
+++ b/tests/misc/tspellsuggest.nim
@@ -23,7 +23,7 @@ candidate misspellings (edit distance, lexical scope distance):
 '''
 """
 
-# tests `--spellsuggest`
+# tests `--spellsuggest:num`
 
 
 
diff --git a/tests/misc/tspellsuggest2.nim b/tests/misc/tspellsuggest2.nim
new file mode 100644
index 000000000000..fc3d9668a896
--- /dev/null
+++ b/tests/misc/tspellsuggest2.nim
@@ -0,0 +1,45 @@
+discard """
+  # pending bug #16521 (bug 12) use `matrix`
+  cmd: "nim c --spellsuggest --hints:off $file"
+  action: "reject"
+  nimout: '''
+tspellsuggest2.nim(45, 13) Error: undeclared identifier: 'fooBar'
+candidate misspellings (edit distance, lexical scope distance):
+ (1, 0): 'fooBar8' [var declared in tspellsuggest2.nim(43, 9)]
+ (1, 1): 'fooBar7' [var declared in tspellsuggest2.nim(41, 7)]
+ (1, 3): 'fooBar1' [var declared in tspellsuggest2.nim(33, 5)]
+ (1, 3): 'fooBar2' [let declared in tspellsuggest2.nim(34, 5)]
+ (1, 3): 'fooBar3' [const declared in tspellsuggest2.nim(35, 7)]
+ (1, 3): 'fooBar4' [proc declared in tspellsuggest2.nim(36, 6)]
+ (1, 3): 'fooBar5' [template declared in tspellsuggest2.nim(37, 10)]
+ (1, 3): 'fooBar6' [macro declared in tspellsuggest2.nim(38, 7)]
+ (1, 5): 'FooBar' [type declared in mspellsuggest.nim(5, 6)]
+ (1, 5): 'fooBar4' [proc declared in mspellsuggest.nim(1, 6)]
+ (1, 5): 'fooBar9' [var declared in mspellsuggest.nim(2, 5)]
+ (1, 5): 'fooCar' [var declared in mspellsuggest.nim(4, 5)]
+'''
+"""
+
+# tests `--spellsuggest`
+
+
+
+
+
+
+# line 30
+import ./mspellsuggest
+
+var fooBar1 = 0
+let fooBar2 = 0
+const fooBar3 = 0
+proc fooBar4() = discard
+template fooBar5() = discard
+macro fooBar6() = discard
+
+proc main =
+  var fooBar7 = 0
+  block:
+    var fooBar8 = 0
+    const fooBarBaz = 0
+    let x = fooBar