[ysh/builtin] toJson() toJson8() accepts space=

The default value is zero.  We're going to change json write to have a
default value of 2.

And get rid of flags --pretty=F and --indent=0

builtin/func_misc.py

@@ -414,14 +414,21 @@ def Call(self, rd):
         # type: (typed_args.Reader) -> value_t
 
         val = rd.PosValue()
+        space = mops.BigTruncate(rd.NamedInt('space', 0))
         rd.Done()
 
+        # Convert from external JS-like API to internal.
+        if space <= 0:
+            indent = -1
+        else:
+            indent = space
+
         buf = mylib.BufWriter()
         try:
             if self.is_j8:
-                j8.PrintMessage(val, buf, -1)
+                j8.PrintMessage(val, buf, indent)
             else:
-                j8.PrintJsonMessage(val, buf, -1)
+                j8.PrintJsonMessage(val, buf, indent)
         except error.Encode as e:
             # status code 4 is special, for encode/decode errors.
             raise error.Structured(4, e.Message(), rd.LeftParenToken())
@@ -457,3 +464,6 @@ def Call(self, rd):
             raise error.Structured(4, e.Message(), rd.LeftParenToken(), props)
 
         return val
+
+
+# vim: sw=2

doc/ref/chap-builtin-func.md

@@ -319,10 +319,15 @@ Note, you will need to `source --builtin list.ysh` to use this function.
 
 Convert an object in memory to JSON text:
 
-    = toJson({name: "alice"})
-    (Str)   '{"name": "alice"}'
+    $ = toJson({name: "alice"})
+    (Str)   '{"name":"alice"}'
 
-Similar to `json write ({name: "alice"})`.
+Add indentation by passing the `space` param:
+
+    $ = toJson([42], space=2)
+    (Str)   "[\n  42\n]"
+
+Similar to `json write (x)`, except the default value of `space` is 0.
 
 See [json-encode-err](chap-errors.html#json-encode-err) for errors.
 

spec/ysh-json.test.sh

@@ -63,7 +63,6 @@ json write ([{k: 'v', k2: 'v2'}, {}])
 #### json write compact format
 shopt --set parse_proc
 
-# TODO: ORDER of keys should be PRESERVED
 var mydict = {name: "bob", age: 30}
 
 json write --pretty=0 (mydict)
@@ -600,28 +599,59 @@ for j in '"\ud83e"' '"\udd26"' {
 "\udd26"
 ## END
 
-#### toJson() toJson8() - TODO: test difference
+#### toJson() toJson8()
 
-var obj = [42, 1.5, null, true, "hi"]
+var obj = [42, 1.5, null, true, "hi", b'\yf0']
 
 echo $[toJson(obj)]
 echo $[toJson8(obj)]
 
+var obj2 = [3, 4]
+echo $[toJson(obj2, space=0)]  # same as the default
+echo $[toJson8(obj2, space=0)]
+
+echo $[toJson(obj2, space=2)]
+echo $[toJson8(obj2, space=2)]
+
+# fully specify this behavior
+echo $[toJson(obj2, space=-2)]
+echo $[toJson8(obj2, space=-2)]
+
 ## STDOUT:
-[42,1.5,null,true,"hi"]
-[42,1.5,null,true,"hi"]
+[42,1.5,null,true,"hi","�"]
+[42,1.5,null,true,"hi",b'\yf0']
+[3,4]
+[3,4]
+[
+  3,
+  4
+]
+[
+  3,
+  4
+]
+[3,4]
+[3,4]
 ## END
 
-#### fromJson() fromJson8() - TODO: test difference
+#### fromJson() fromJson8()
 
-var message ='[42,1.5,null,true,"hi"]'
+var m1 = '[42,1.5,null,true,"hi"]'
 
-pp line (fromJson(message))
-pp line (fromJson8(message))
+# JSON8 message
+var m2 = '[42,1.5,null,true,"hi",' ++ "u''" ++ ']'
 
+pp line (fromJson8(m1))
+pp line (fromJson(m1))
+
+pp line (fromJson8(m2))
+pp line (fromJson(m2))  # fails
+
+## status: 4
 ## STDOUT:
 (List)   [42,1.5,null,true,"hi"]
 (List)   [42,1.5,null,true,"hi"]
+(List)   [42,1.5,null,true,"hi",""]
 ## END
 
 #### User can handle errors - toJson() toJson8()

ysh/expr_to_ast.py

@@ -805,8 +805,9 @@ def _CheckLhs(self, lhs):
 
             else:
                 # Illegal - e.g. setglobal {}["key"] = 42
-                p_die("Subscript and Attribute not allowed on this LHS expression",
-                      location.TokenForExpr(lhs))
+                p_die(
+                    "Subscript/Attribute not allowed on this LHS expression",
+                    location.TokenForExpr(lhs))
 
     def _LhsExprList(self, p_node):
         # type: (PNode) -> List[y_lhs_t]