Format Str as 'Str "value"' and Space as 'Space'

Previously, Str was formatted as 'Str text: "value"' but that was
inconsistent because it should really have been 'Str {text: "value"}'.
Given the widespread usage of Str, and the fact that its constructor
can be given a string, it makes sense to hide the 'text' attribute name.
The same logic would also apply to other types with single 'text'
attributes.

Similarly, Space was formatted as 'Space {}' but it's so common that
it makes sense to omit its empty contents.

Author: wlupton

logging.lua

@@ -104,14 +104,13 @@ local function dump_(prefix, value, maxlen, level, add)
             end
         end
         if numKeys == 0 then
-            -- this (for example) avoids a newline in 'Space {}'
-            -- XXX this wouldn't be needed with proper maxlen handling
-            value = '{}'
-        elseif numKeys == 1 and lastKey == 'text' and typename == 'Str' then
-            -- this allows strings to be formatted on a single line
+            -- this allows empty tables to be formatted on a single line
+            value = typename == 'Space' and '' or '{}'
+        elseif numKeys == 1 and lastKey == 'text' then
+            -- this allows text-only types to be formatted on a single line
+            typ = typename
+            value = value[lastKey]
             typename = 'string'
-            typ = 'Str text:'
-            value = value.text
         end
     end
 
@@ -122,6 +121,7 @@ local function dump_(prefix, value, maxlen, level, add)
     if valtyp == 'nil' then
         add('nil')
     elseif ({boolean=1, number=1, string=1})[valtyp] then
+        typsep = #typ > 0 and valtyp == 'string' and #value > 0 and ' ' or ''
         local fmt = typename == 'string' and '%q' or '%s'
         add(string.format('%s%s%s%s%s' .. fmt, indent, prefix, presep,
                           typ, typsep, value))