smarter string quoting

_G.yml

@@ -1,22 +1,22 @@
-__root__: &t0x8ec478
- _VERSION: "Lua 5.2"
- add_zeros: f0x8ec3f0
+__root__: &t0x6f478
+ _VERSION: Lua 5.2
+ add_zeros: f0x73838
  assert: f0x1fefc
  collectgarbage: f0x1f930
  dofile: f0x1fe7c
- dump: f0x8f1410
+ dump: f0x78770
  error: f0x1f8c0
- getaddr: f0x8f4c30
+ getaddr: f0x74c40
  getmetatable: f0x1fe2c
  ipairs: f0x1fd24
  load: f0x1ff54
  loadfile: f0x1fd80
  loadstring: f0x1ff54
- mixed_sorter: f0x8f1c28
- module: f0x8ece20
+ mixed_sorter: f0x76c28
+ module: f0x6fe20
  next: f0x1f7ac
- opairs: f0x8f4da0
- order_keys: f0x8f4cc0
+ opairs: f0x74c88
+ order_keys: f0x74cd0
  pairs: f0x1fd04
  pcall: f0x1fb50
  print: f0x1f66c
@@ -24,21 +24,21 @@ __root__: &t0x8ec478
  rawget: f0x1f598
  rawlen: f0x1f5d8
  rawset: f0x1f54c
- rawstr: f0x8f4c78
- require: f0x8edb00
+ rawstr: f0x76460
+ require: f0x70b00
  select: f0x1f444
  setmetatable: f0x1fbc0
- strpad: f0x8f34e8
+ strpad: f0x73e60
  tonumber: f0x1f25c
  tostring: f0x1f234
  type: f0x1f1f8
  unpack: f0x26598
  xpcall: f0x1fa84
- _G: *t0x8ec478
- arg: &t0x8f06b8
-  "-1": "/usr/bin/lua"
-  0: "./run.lua"
- bit32: &t0x8ed190
+ _G: *t0x6f478
+ arg: &t0x736b8
+  "-1": /usr/bin/lua
+  0: ./run.lua
+ bit32: &t0x70190
   arshift: f0x2022c
   band: f0x20458
   bnot: f0x20208
@@ -51,14 +51,14 @@ __root__: &t0x8ec478
   replace: f0x20338
   rrotate: f0x201c4
   rshift: f0x2015c
- coroutine: &t0x8ec998
+ coroutine: &t0x6f998
   create: f0x20844
   resume: f0x20934
   running: f0x20824
   status: f0x206cc
   wrap: f0x20888
   yield: f0x20584
- debug: &t0x8ee7c8
+ debug: &t0x717c8
   debug: f0x20e44
   gethook: f0x21470
   getinfo: f0x21674
@@ -75,7 +75,7 @@ __root__: &t0x8ec478
   traceback: f0x20ff8
   upvalueid: f0x20ca0
   upvaluejoin: f0x20cd8
- io: &t0x8edfe8
+ io: &t0x70fe8
   close: f0x21c94
   flush: f0x22328
   input: f0x22a28
@@ -84,13 +84,13 @@ __root__: &t0x8ec478
   output: f0x22a0c
   popen: f0x2238c
   read: f0x222dc
-  stderr: "file (0x76e559d8)"
-  stdin: "file (0x76e55c98)"
-  stdout: "file (0x76e55b38)"
+  stderr: file (0x76e4f9d8)
+  stdin: file (0x76e4fc98)
+  stdout: file (0x76e4fb38)
   tmpfile: f0x22c70
   type: f0x22890
   write: f0x21ba8
- math: &t0x8efa10
+ math: &t0x72a10
   abs: f0x22e48
   acos: f0x234c8
   asin: f0x234a4
@@ -121,7 +121,7 @@ __root__: &t0x8ec478
   sqrt: f0x22eb4
   tan: f0x22e6c
   tanh: f0x22e90
- os: &t0x8edd90
+ os: &t0x70d90
   clock: f0x237d8
   date: f0x23ac0
   difftime: f0x23758
@@ -133,7 +133,7 @@ __root__: &t0x8ec478
   setlocale: f0x23580
   time: f0x23930
   tmpname: f0x23810
- package: &t0x8ece90
+ package: &t0x6fe90
   config: "\
    /\
    ;\
@@ -141,40 +141,40 @@ __root__: &t0x8ec478
    !\
    -\
    "
-  cpath: "/usr/lib/lua/5.2/?.so;/usr/lib/lua/5.2/loadall.so;./?.so"
+  cpath: /usr/lib/lua/5.2/?.so;/usr/lib/lua/5.2/loadall.so;./?.so
   loadlib: f0x27808
-  path: "/usr/share/lua/5.2/?.lua;/usr/share/lua/5.2/?/init.lua;/usr/lib/lua/5.2/?.lua;/usr/lib/lua/5.2/?/init.lua;./?.lua"
+  path: /usr/share/lua/5.2/?.lua;/usr/share/lua/5.2/?/init.lua;/usr/lib/lua/5.2/?.lua;/usr/lib/lua/5.2/?/init.lua;./?.lua
   searchpath: f0x27ad4
   seeall: f0x273e0
-  searchers: *t0x8ed5b0
-  loaded: &t0x8ec948
+  searchers: *t0x705b0
+  loaded: &t0x6f948
    extra: true
-   _G: *t0x8ec478
-   bit32: *t0x8ed190
-   coroutine: *t0x8ec998
-   debug: *t0x8ee7c8
-   io: *t0x8edfe8
-   math: *t0x8efa10
-   os: *t0x8edd90
-   package: *t0x8ece90
-   string: *t0x8ed340
-   table: *t0x8edb68
-   pt: &t0x8f5be8
-    __call: f0x8f12a0
-    inner: f0x8f5a10
-    outer: f0x8f4de0
-    safekey: f0x8f1dc0
-    safeval: f0x8ec230
-    write: f0x8f3890
-    __index: *t0x8f5be8
-    __metatable: *t0x8f5be8
-  loaders: &t0x8ed5b0
-   1: f0x8ed620
-   2: f0x8ed648
-   3: f0x8ed670
-   4: f0x8ed698
-  preload: &t0x8ed720
- string: &t0x8ed340
+   _G: *t0x6f478
+   bit32: *t0x70190
+   coroutine: *t0x6f998
+   debug: *t0x717c8
+   io: *t0x70fe8
+   math: *t0x72a10
+   os: *t0x70d90
+   package: *t0x6fe90
+   string: *t0x70340
+   table: *t0x70b68
+   pt: &t0x78948
+    __call: f0x75128
+    inner: f0x76d00
+    outer: f0x74410
+    safekey: f0x77de8
+    safeval: f0x6f2d0
+    write: f0x6f360
+    __index: *t0x78948
+    __metatable: *t0x78948
+  loaders: &t0x705b0
+   1: f0x70620
+   2: f0x70648
+   3: f0x70670
+   4: f0x70698
+  preload: &t0x70720
+ string: &t0x70340
   byte: f0x25234
   char: f0x24768
   dump: f0x254d4
@@ -189,20 +189,20 @@ __root__: &t0x8ec478
   reverse: f0x23fb8
   sub: f0x2518c
   upper: f0x23ed8
- t: &t0x8f1bd0
+ t: &t0x74a30
   C: hello
-  D: *t0x8f1bd0
-  A: &t0x8f1d98
+  D: *t0x74a30
+  A: &t0x74b78
    a: beep
    b: boop
    c: burp
-   d: *t0x8f5f90
-  B: &t0x8f5f90
+   d: *t0x786c0
+  B: &t0x786c0
    a: nude
    b: dude
    c: lewd
-   d: *t0x8f1d98
- table: &t0x8edb68
+   d: *t0x74b78
+ table: &t0x70b68
   concat: f0x2691c
   insert: f0x26688
   maxn: f0x26818

pt.lua

@@ -53,7 +53,8 @@ function pt.safeval(v, indent)
         return s
     end
     s = s:find('[\r\n]') and ('\n'..s):gsub('[\r\n]', '\n'..indent..' ') or s
-    return s:find('[^%w_]') and ('%q'):format(s) or s
+    local safe = ('%q'):format(s)
+    return s == safe:sub(2, -2) and s or safe
 end
 
 function pt:inner(k, v, indent)

run.lua

@@ -37,4 +37,4 @@ function dump(t, fn, seen)
 end
 
 pt(t)
-dump(_G, '!_G.yml')
+dump(_G, '_G.yml')