Each transient identifies the value of the corresponding previous bytecode.
This change (a) frees up many bytecodes formerly used by the conditional
expression (if c t f); (b) regularizes the bytecode by always placing opcodes
before operands; and (c) causes the bytecode to conform to the Single Static
Assignment (SSA) form preferred by e.g. LLVM.
Includes updates to the hand-assembled files (*.rla) and the bytecode compiler.
Eliminate use of #="undefined" as an explicit initializer for boxes.
Do not allow #@ ("freeze") to be applied to references, for sanity's sake.
Inside compiler, builtins are now represented by (#%builtin "name") form.
Plain symbols are promoted to builtins; quoted symbols become structures.
Fix choice of continuation when function ends in (call/cc).
Change empty kw-args from '() to #%nil in (simplify-apply).
Improve error message when no match is found for a primitive form.
Add special variables for keyword arguments & values.
Add support for keyword arguments to (simplify-apply).
Implement full string parsing in src/reader.rls.
TODO: Support keywords in (simplify-lambda) and writer.
Fix assertion in gc_object_left_behind() to work in Gen-0 collection.
Add (weak-box?) and (make-weak-box) primitives. (unbox) now works for both.
Add option to just simplify the input (stops before reduce-function).
Default to writing .rla without indentation, comments, or newlines.
Add support for (fix=), (list), (and), (or), (cond), (when), and (unless).
Fix a mapper bug which could assign the same frame var to separate variables.
Update make-struct primitive for new structure type layout.
Change primitives to use #% as prefix instead of just %.
Add primitive operations for comparing byte-strings.
Pairs, boxes, and strings are hashed by values; vectors and structures
are "hashed" by reference. Takes into account the possibility of cycles.
This is a prelude to implementing hash-tables.
* Remap all instance variables in one pass, to avoid an insidious bug [1].
* Fix another bug by merging promote-shared-variables and narrow-binds [2].
* Don't assume different variable means different value in propogate-set!.
* Add support for (apply), (value-list) and (call-with-values) forms.
* Add support for including files (as if directly substituted) in reader.
* Use scheme/match library to simplify form pattern-matching.
* Refactor (map-form) and (search-form) using a more basic (traverse-form),
which just recurses over the form and returns void by default, and a
new utility function (curry-keywords) to provide default keyword arguments.
[1] Was renaming e.g. %f0 to %i0, then %i0 to %i1, which eliminates the
distinction between %f0 and %i0. Solution is to construct a map from old
names to new names, then traverse the form and change every old variable
to its new equivalent in the map exactly once.
[2] Some variables were not being promoted to boxes, as promotions only occur
at the top-level, when constructing each lambda, and narrow-binds could push
the unpromoted variables down into a subordinate lambda form first. Solution
was to promote variables immediately after narrowing bindings, including the
recursive calls which exist after pushing variables into nested scopes.
Module consists of mixed (declare ...) forms and expressions.
Groups of (declare ...) forms become (letrec ...)s surrounding
later expressions and (declare ...) groups.
The (declare (fn-name . arglist) forms...) syntax is supported.
Created one module one per pass, plus utilities functions, primitives, and output.
Changed extension to ".scm" for compatibility with hg syntax highlighting backend.
Was moving (set!) into the (%bind) form, and thus setting the wrong variable.
Now, if set! var is bound, will create a temporary for result of %bind first,
and set! original variable to temporary in the proper scope.
Also, normalize rules for nested (%bind)s:
* The (%bind) inside a (%lambda) is always flat.
- This is a responsiblity of simplify-lambda, and any function which
may change structure after simplification (e.g. promote-to-box).
* Any other (%bind) may be nested, unless otherwise noted.
Also:
- assume top-level free variables are constants, not boxes;
- bind variable 'argv' to top-level argument list, rather than assuming no arguments;
- make %values a first-class form, just like %apply and %call/cc (was: pseudo-primitive);
- fix case where 'rest' argument is sole item in argument list: (lambda argv ...); and
- perform misc. cleanup in output code.
Also performed misc. cleanup, corrected use of temp variables in (let ...),
changed make-bindings-unique to preserve original names as prefixes, improved
detection of unused %set! forms in reduce-set!, and fixed map-variables to
extract the real value from (quote ...) literal forms.
Jesse D. McDonald