Fixed some bugs, including upgrade --upgrade-from=version not working.

Also updated the README.

README.md

@@ -2,7 +2,8 @@
 
 Nomsu (named after **Nom**ic, and its creator, Peter **Su**ber) is a programming language
 designed to be used for playing games of [Nomic](https://en.wikipedia.org/wiki/Nomic), or engaging in other similar activities
-revolving around natural language rule-making and self modification.
+revolving around natural language rule-making and self modification. More information is
+available at [Nomsu's homepage](https://nomsu.org).
 
 ## Dependencies
 
@@ -21,17 +22,17 @@ There's a more complete set of example code in [examples/how\_do\_i.nom](example
 ```
 say "Hello"
 
-%my_nums = [5, 23, 42]
+$my_nums = [5, 23, 42]
-for %num in %my_nums:
+for $num in $my_nums:
-    say "\%num is one of my nums"
+    say "\$num is one of my nums"
 
-(sing %n bottles of beer) means:
+(sing $n bottles of beer) means:
-    for %i in %n to 1 by -1:
+    for $i in $n to 1 by -1:
-        say "\
+        say "
-            ..\%i bottle\("s" if (%i > 1) else "") of beer on the wall,
+            \$i bottle\("s" if ($i > 1) else "") of beer on the wall,
-            \%i bottle\("s" if (%i > 1) else "") of beer!
+            \$i bottle\("s" if ($i > 1) else "") of beer!
             Take one down, pass it around..."
-    say "No bottles of beer on the wall. Go to the store, buy some more..."
+    say "No bottles of beer on the wall."
 
 sing 99 bottles of beer
 ```

core/metaprogramming.nom

@@ -301,10 +301,7 @@ externally ($ is $kind syntax tree) means (..)
 
 ($tree with $t -> $replacement) compiles to "
     \($tree as lua expr):map(function(\($t as lua expr))
-        \(..)
+        \(=lua "\$replacement.type == 'Block' and \($replacement as lua) or 'return '..\($replacement as lua expr)")
-        ($replacement as lua) if ($replacement.type == "Block") else \
-        .."return \($replacement as lua expr)"
-    ..
     end)"
 
 externally ($tree with vars $replacements) means (..)

nomsu_environment.lua

@@ -137,7 +137,7 @@ local nomsu_environment = Importer({
   compile_error_at = compile_error,
   _1_forked = _1_forked,
   import_to_1_from = import_to_1_from,
-  _1_parsed = function(nomsu_code)
+  _1_parsed = function(nomsu_code, syntax_version)
     if type(nomsu_code) == 'string' then
       local filename = Files.spoof(nomsu_code)
       nomsu_code = NomsuCode:from(Source(filename, 1, #nomsu_code), nomsu_code)
@@ -145,11 +145,14 @@ local nomsu_environment = Importer({
     local source = nomsu_code.source
     nomsu_code = tostring(nomsu_code)
     local version = nomsu_code:match("^#![^\n]*nomsu[ ]+-V[ ]*([0-9.]+)")
-    local syntax_version = version and tonumber(version:match("^[0-9]+")) or max_parser_version
+    if syntax_version then
+      syntax_version = tonumber(syntax_version:match("^[0-9]+"))
+    end
+    syntax_version = syntax_version or (version and tonumber(version:match("^[0-9]+")) or max_parser_version)
     local parse = Parsers[syntax_version] or Parsers[max_parser_version]
     local tree = parse(nomsu_code, source.filename)
     if tree.shebang then
-      tree.version = tree.shebang:match("nomsu %-V[ ]*([%d.]*)")
+      tree.version = tree.version or tree.shebang:match("nomsu %-V[ ]*([%d.]*)")
     end
     local errs = { }
     local find_errors

nomsu_environment.moon

@@ -60,18 +60,20 @@ nomsu_environment = Importer{
     compile: compile, _1_as_lua: compile, compile_error_at:compile_error,
     :_1_forked, :import_to_1_from,
 
-    _1_parsed: (nomsu_code)->
+    _1_parsed: (nomsu_code, syntax_version)->
         if type(nomsu_code) == 'string'
             filename = Files.spoof(nomsu_code)
             nomsu_code = NomsuCode\from(Source(filename, 1, #nomsu_code), nomsu_code)
         source = nomsu_code.source
         nomsu_code = tostring(nomsu_code)
         version = nomsu_code\match("^#![^\n]*nomsu[ ]+-V[ ]*([0-9.]+)")
-        syntax_version = version and tonumber(version\match("^[0-9]+")) or max_parser_version
+        if syntax_version
+            syntax_version = tonumber(syntax_version\match("^[0-9]+"))
+        syntax_version or= version and tonumber(version\match("^[0-9]+")) or max_parser_version
         parse = Parsers[syntax_version] or Parsers[max_parser_version]
         tree = parse(nomsu_code, source.filename)
         if tree.shebang
-            tree.version = tree.shebang\match("nomsu %-V[ ]*([%d.]*)")
+            tree.version or= tree.shebang\match("nomsu %-V[ ]*([%d.]*)")
         errs = {}
         find_errors = (t)->
             if t.type == "Error"

tools/upgrade.nom

@@ -22,7 +22,7 @@ for $filename in $args.extra_args:
         barf "File does not exist: \$filename"
     $leading_indent = ($file|matching "[\n]*([ ]*)")
     $code = (NomsuCode from (Source $filename 1 (size of $file)) $file)
-    $tree = ($code parsed)
+    $tree = ($code parsed $start_version)
     $uptree = (..)
         $tree upgraded from ($start_version or ($tree.version or (Nomsu version))) to \
         ..$version