[mycpp] Don't create new vars in case blocks, unless var is UP_*

We are making the "UP_val downcasting pattern" real in mycpp.

This fixes a failing test case in

    test/spec-cpp.sh run-file ysh-methods

Related to casting "out" of a switch.

Document many more things in mycpp/README.md.  Publish it in
doc/oils-repo/mycpp/README.html.

Also move our README.md from doc/README.html to
doc/oils-repo/README.html.

README.md

@@ -312,6 +312,6 @@ There are README files in many subdirectories, like
 * [oilshell.zulipchat.com][] is for any kind of discussion
 * Subscribe for updates:
   * [/r/oilshell on Reddit](https://www.reddit.com/r/oilshell/)
-  * [@oilshellblog on Twitter](https://twitter.com/oilshellblog)
+  * [@oilsforunix on Twitter](https://twitter.com/oilsforunix)
 
 

build/doc.sh

@@ -21,6 +21,9 @@ REPO_ROOT=$(cd $THIS_DIR/.. && pwd)
 readonly REPO_ROOT
 
 
+readonly HTML_BASE_DIR=_release/VERSION
+
+
 log() {
   echo "$@" 1>&2
 }
@@ -167,7 +170,7 @@ split-and-render() {
   local rel_path=${src%'.md'}  # doc/known-differences
   local tmp_prefix=_tmp/$rel_path  # temp dir for splitting
 
-  local out=${2:-_release/VERSION/$rel_path.html}
+  local out=${2:-$HTML_BASE_DIR/$rel_path.html}
   local web_url=${3:-'../web'}
 
   mkdir -v -p $(dirname $out) $tmp_prefix
@@ -227,8 +230,6 @@ render-from-kate() {
 # Do NOT split because we don't want front matter in the markdown source.
 render-only() {
   local src=${1:-README.md}
-  local css_files=${2:-'../web/manual.css ../web/toc.css'}
-  local title=${3:-'Oils Source Code'}
 
   local name
   case $src in 
@@ -243,8 +244,11 @@ render-only() {
       ;;
   esac
 
+  local out=${2:-$HTML_BASE_DIR/doc/$name.html}
+  local css_files=${3:-'../web/manual.css ../web/toc.css'}
+  local title=${4:-'Oils Source Code'}
+
   local prefix=_tmp/doc/$name
-  local out=_release/VERSION/doc/$name.html
 
   local meta=${prefix}_meta.json 
   cat >$meta <<EOF
@@ -263,8 +267,18 @@ EOF
 }
 
 special() {
-  render-only 'README.md' '../web/base.css ../web/manual.css ../web/toc.css' 'Oils Source Code'
-  render-only 'INSTALL.txt' '../web/base.css ../web/install.css' 'Installing Oils'
+  # TODO: do all READMEs
+  split-and-render mycpp/README.md \
+    $HTML_BASE_DIR/doc/oils-repo/mycpp/README.html \
+    ../../../web
+
+  local web_dir='../../web'
+  render-only 'README.md' $HTML_BASE_DIR/doc/oils-repo/README.html \
+    "$web_dir/base.css $web_dir/manual.css $web_dir/toc.css" 'Oils Source Code'
+
+  local web_dir='../web'
+  render-only 'INSTALL.txt' '' \
+    "$web_dir/base.css $web_dir/install.css" 'Installing Oils'
 
   # These pages aren't in doc/
   split-and-render doc/release-index.md _tmp/release-index.html

core/state.py

@@ -744,29 +744,26 @@ def _DumpVarFrame(frame):
 
         # TODO:
         # - Use packle for crash dumps!  Then we can represent object cycles
+        #   - Right now the JSON serializer will probably crash
         #   - although BashArray and BashAssoc may need 'type' tags
         #     - they don't round trip correctly
         #     - maybe add value.Tombstone here or something?
         #   - value.{Func,Eggex,...} may have value.Tombstone and
         #   vm.ValueIdString()?
 
-        val = None  # type: value_t
         with tagswitch(cell.val) as case:
             if case(value_e.Undef):
                 cell_json['type'] = value.Str('Undef')
 
             elif case(value_e.Str):
-                val = cast(value.Str, cell.val)
                 cell_json['type'] = value.Str('Str')
-                cell_json['value'] = value.Str(val.s)
+                cell_json['value'] = cell.val
 
             elif case(value_e.BashArray):
-                val = cast(value.BashArray, cell.val)
                 cell_json['type'] = value.Str('BashArray')
                 cell_json['value'] = cell.val
 
             elif case(value_e.BashAssoc):
-                val = cast(value.BashAssoc, cell.val)
                 cell_json['type'] = value.Str('BashAssoc')
                 cell_json['value'] = cell.val
 

doc/architecture-notes.md

@@ -14,7 +14,7 @@ These internal details are subject to change.
 ## Links
 
 - [Contributing][] (wiki) helps you change the code for the first time.
-- [README](README.html) describes how the code is organized.
+- [README](oils-repo/README.html) describes how the code is organized.
 - [Interpreter State](interpreter-state.html) describes the interpreter's user-facing data
   structures.
 - [Parser Architecture](parser-architecture.html)

doc/index.md

@@ -133,8 +133,8 @@ Internal details:
 
 ## For Contributors
 
-- [README.md](README.html).  If you want to modify Oils, start here.  We
-  welcome contributions!
+- [README.md](oils-repo/README.html).  If you want to modify Oils, start here.
+  We welcome contributions!
 - [Doc Toolchain](doc-toolchain.html) and [Doc Plugins](doc-plugins.html).
 - [Github Wiki for oilshell/oil](https://github.com/oilshell/oil/wiki)
 - [Old Docs](old/index.html).  Drafts that may be deleted.
@@ -144,6 +144,8 @@ Internal Architecture:
 - [Notes on Oils Architecture](architecture-notes.html)
   - [Parser Architecture](parser-architecture.html)
 - [Pretty Printing](pretty-printing.html) - March 2024 design notes.
+- [mycpp/README](oils-repo/mycpp/README.html) - How we translate typed Python to
+  C++.
 
 ## More
 

doc/pretty-printing.md

@@ -444,7 +444,8 @@ tree with "NIL8":
   **"lossless invariant"**, which is affected by *re-parsing*.
   - I recently updated it, and tested the invariant with
     [test/lossless.sh]($oils-src).
-- The repo [README]($oils-doc:README.html) has an overview of the code.
+- The repo [README]($oils-doc:oils-repo/README.html) has an overview of the
+  code.
 
 ### Fun Computer Science Problems in Oils