This commit removes the dependency upon Mycelium::sexpr::Datum from Hyphae
and instead adds a heap.rs module including three types:
- Gc: This is essentially a Box<Rc<T>> but passed around as a *const Rc<T>.
not only does this allow the wrapped T to be passed around in a format
that fits completely within a single physical register, this also
applies a greedy reference counting garbage collection to each and
every object allocated in the VM.
- Datum: This is a simplified enum for type polymorphism. Similar to the
original Mycelium::sexpr::Datum.
- Cons: This is a very standard Cons cell type.
Additionally, two new instructions are added:
- DUPL: a deep copy instruction
- CONST: an instruction to create number datum from embedded constants
- NTOI: casts a number to its inexact form
- NTOE: casts a number to its exact form
Fixes: #35 and #36
Signed-off-by: Ava Affine <ava@sunnypup.io>
The number package is moved into its own package henceforth referred
to as "organelle". Hyphae and Mycelium are updated accordingly. In
addition, Hyphae gets a copy of the sexpr module of Mycelium. This
will not remain a copy, rather it will be the basis of a heap manager
module within Mycelium to be worked on in the future.
Fixes#32
Signed-off-by: Ava Affine <ava@sunnypup.io>
This commit adds a number library which handles fractions, floats,
whole numbers, scientific notation, and special symbolic numbers
all according to the R7RS small specification.
Numeric trait is used to abstract operations across all number types
and a Number enum is used to offer a non-opaque type that stores any
kind of number.
Upon the Number enum is implemented the following traits:
- Add, Div, Sub, Mul
- Pow
- PartialEq
- PartialOrd
Which then offer the following operators to use on the Number enum
instances themselves: + - / * == != < > <= >= and of course x.pow(y).
Additionally, the number package contains parsing logic for each type
of number. FromStr is implemented as part of the Numeric trait, and
then in turn implemented on Number. Additionally Into<String> is
implemented for the Numeric trait and then on the Number enum type
as well.
Test cases have been added for basic cases, but could be expanded.
Additional modifications:
- LexError has a custom display implementation that properly outputs
formatted errors.
- Sexpr package updated to use new number package
Signed-off-by: Ava Affine <ava@sunnypup.io>
The lexer is complete with tests. It fully encapsulates the logic
of splitting an input document into a stream of tokens. It can be
instantiated from an Rc<str>, meaning no lifetimes need be managed
references to the original document (like a stringview) can be
passed around carelessly. The Lexer implements the iterator
method which should help elegantly design repls / compilers, etc.
The S-Expression data type represents the parsed AST. The actual
parsing logic is yet to be added. It is intended that the AST be
the last step before compiling to bytecode. The data representation
here is cons cells of datum. Formatting is implemented.
Signed-off-by: Ava Affine <ava@sunnypup.io>
