Instead of passing around references to the environment, just treat it
as a global. The old way was just the remains of an idea to make the
environment immutable and keep the interpreter from manipulating any
global state. By making everything global and mutable, we will have
less impedance mismatch with POSIX going forward.
The following changelog is only a sketch, since nearly every function
has changed.
* geesh/environment.scm: Replace this module with one that treats the
environment as a global resource.
* tests/environment.scm: Delete file.
* Makefile.am: Remove it from the list of tests.
* geesh/shell.scm, geesh/eval.scm, geesh/repl.scm, geesh/word.scm,
geesh/built-ins/break.scm, geesh/built-ins/continue.scm,
geesh/built-ins/echo.scm, geesh/built-ins/export.scm,
geesh/built-ins/false.scm, geesh/built-ins/read.scm,
geesh/built-ins/readonly.scm, geesh/built-ins/set.scm,
geesh/built-ins/true.scm, geesh/built-ins/unset.scm: Remove 'env'
parameters and use the new environment module.
* .dir-locals.el: Update indentation of functions that no longer take
an 'env' parameter and add with-arguments, with-environ, and
with-variables from the new environment module.
* tests/shell.scm, tests/word.scm: Update environment creation and
manipulation in tests.
Instead of using an environment variable named '?', we will use a
special environment field called 'status'. This lets us get rid of a
lot of number-string conversions (since an environment variable has to
have a string value).
* geesh/environment.scm (<environment>): Add a 'status' field.
(make-environment): Set it to 0 by default.
* geesh/repl.scm (run-repl): Use new field in place of '?' variable.
* geesh/shell.scm (exec-utility, sh:and, sh:exec-let, sh:for, sh:not,
sh:or, sh:pipeline, sh:subshell, sh:substitute-command): Ditto.
* geesh/word.scm (parameter-ref): New function that handles both
special parameters (e.g., '?') and variables.
(parameter-ref*): Like 'var-ref*', but for 'parameter-ref'.
(word->qword): Replace 'var-ref' and 'var-ref*' with 'parameter-ref'
and 'parameter-ref*' respectively.
Timothy Sample