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.
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.
* 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.
Created one module one per pass, plus utilities functions, primitives, and output.
Changed extension to ".scm" for compatibility with hg syntax highlighting backend.
Jesse D. McDonald