Previously, to avoid showing deprecation warnings for the next release when the
user is running on HEAD, a boolean CLI flag -show-deprecations is introduced,
and is set to false in the master branch. The idea is that release branches will
have this default to true, so people running released versions will see
deprecations.
However, this means that people running on HEAD will never see any deprecations
unless they use this CLI flag, which is not ideal. This commit replaces the flag
bool -show-deprecations with a numerical -deprecation-level flag, which requests
deprecations that are active as of release 0.X to be shown. The default value of
this flag will be the minor version number of the *last* release, so that people
running HEAD will see as many deprecation warnings as people running the last
release would. This number will be bumped just before releases.
- Move NewEnvListVar to pkg/eval/vars.
- De-export GlobPattern, GlobFlag and ExternalCmd.
- Merge editor.go and chdir.go into eval.go, value_helper.go into compile_value.go.
- Remove eval_internal_test.go and replace it with a new test for $pid.
This change makes Ns immutable from the exposed API. Internally there is exactly
one place that still mutates Ns, in scopeOp; this will be addressed later.
- Make Evaler mostly thread-safe. The only remaining thread-unsafe part is the
modules field, which is more tricky than other fields.
- Remove the state and evalerScopes type, and move their fields into Evaler.
- Expose valuePrefix via a get method, and change PortsFromFiles to take the
prefix instead of a *Evaler. Also expose a PortsFromStdFiles.
- Make Evaler a normal field of Frame, instead of an embedded field. This makes
access to global states more explicit.
Most of the places that need to directly call a function is in the edit package,
which need to call user-defined callbacks.
This change eliminates most call sites of NewTopFrame (including all call sites
outside the eval package). Remove the function and inline it in the remaining
few call sites.
Remove NewTopFrame means that the eval package no longer offers other packages
a way to construct Frame instances. This is intended: Frame is a relatively
low-level concept, and all code outside the eval package now uses the more
high-level Eval, Call, Check/CheckTree methods of *Evaler. The most notable
exception is packages that implement modules; they may still use Frame to access
the information kept in it, but they never construct Frame instances.
In future, the Frame type can be changed to an interface.
This method has the property that it always tries to compile the code even if
there is a parse failure. This is the more desirable behavior when checking
code: if there is a parse failure near the end of a chunk of code, the user may
like to learn about compile errors earlier in the code.
The behavior is controlled by a global flag that will be flipped for the release
branch. A flag is available to force deprecations to be shown or hidden.
