Compiler
The compiler is implemented in Rust.
To work around Rust's restrictions on circular references, index-based data-structures are used heavily.
Standard Library
The standard library is implemented in Core itself, though some types and functions exposed in the standard library are implemented as intrinsics provided by the runtime.
Intermediate Representation
There is currently no real intermediate representation or even a persisted compilation artifact, thecore executable is both compiles and runs the code on-the-fly.
Runtime
The runtime is implemented in Rust.Code Generation
Code is generated at runtime, just-in-time.
The backend is implemented specifically for Core and does not rely on the LLVM or other frameworks.
Supported architectures are AMD64 and ARM64. A backend for the RISC-V architecture (RV64G) is work-in-progress.
Garbage Collection
While the language encourages the use of immutable value types (keyword value),
reference-based types (keyword class) are available and managed by precise garbage collection.
Memory Layout
This is a design draft.
high addresses non-canonical addresses low addresses
+---------------+---------------+---------------+---------------+---------------+---------------+---------------+---------------+
OS process: | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ |
+---------------+---------------+---------------+---------------+---------------+---------------+---------------+---------------+
╰───────────────┬───────────────╯
available user-space virtual memory (128TiB address space)
+---------------+---------------+---------------+---------------+---------------+---------------+---------------+---------------+
Core runtime: | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊XXX| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ x ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊x |
+---------------+---------------+---------------+---------------+---------------+---------------+---------------+---------------+
╰─┬─╯ | |
1TiB: reserved object space ?MiB: reserved code space 1GiB: reserved vtable space
... allocators will then work with these reserved spaces, committing memory by placing data in those spaces.
Core alloc: ...
Core GC: ...
Object Layout
Values
Numbers
integer values (64 bit)
+---------------+---------------+
| ┊ ┊ ┊ | ┊ ┊ ┊ |
+---------------+---------------+
╰───────────────┬───────────────╯
64 bits: signed value
integer values (32 bit)
+---------------+
| ┊ ┊ ┊ |
+---------------+
╰───────┬───────╯
32 bits: signed value
floating-point values (64 bit)
11 bits: exponent
╭──┴─╮
+---------------+---------------+
| ┊ ┊ ┊ | ┊ ┊ ┊ |
+---------------+---------------+
│ ╰─────────────┬───────────╯
1 bit: sign 52 bits: mantissa
floating-point values (32 bit)
8 bits: exponent
╭─┴─╮
+---------------+
| ┊ ┊ ┊ |
+---------------+
│ ╰────────┬─╯
1 bit: sign 23 bits: mantissa
Unions
tag-based union values
+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | union value ...
+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰───────┬───────╯
32 bits: tag bits
References
There is ongoing work to reduce the size of the object headers (which contain a vtable pointer and forwarding pointer) from 16 bytes to 8 bytes.
This will decrease the size of everything reference-based – of regular class instances, array and string instances, trait-boxed instances and reference-based union instances.
regular class instances
37 bits: forwarding pointer
╭───────┴─────────╮
+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | instance fields ...
+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰─────┬─────╯ ╰─┤
24 bits: vtable pointer 3 bits: fwd/mark bits
array instances
37 bits: forwarding pointer 64 bits: array size
╭───────┴─────────╮ ╭───────────────┴───────────────╮
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | array elements ...
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰─────┬─────╯ ╰─┤
24 bits: vtable pointer 3 bits: fwd/mark bits
string instances
37 bits: forwarding pointer 36 bits: string size
╭───────┴─────────╮ ╭───────┴─────────╮
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | utf8 bytes ...
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰─────┬─────╯ ╰─┤ ╰───────┬───────╯
24 bits: vtable pointer 3 bits: fwd/mark bits 32 bits: hash code
trait-boxed instances
37 bits: forwarding pointer
╭───────┴─────────╮
+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | instance ...
+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰─────┬─────╯ ╰─┤
24 bits: vtable pointer 3 bits: fwd/mark bits
Classes
regular class instances
62 bits: vtable pointer 61 bits: forwarding pointer
╭───────────────┴──────────────╮╭───────────────┴─────────────╮
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ ┊ ┊ ┊ ┊ | instance fields ...
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰┤ ╰─┤
2 bits: forward bits 3 bits: mark bits
array instances
62 bits: vtable pointer 61 bits: forwarding pointer 64 bits: array size
╭───────────────┴──────────────╮╭───────────────┴─────────────╮ ╭───────────────┴───────────────╮
+---------------+---------------+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ ┊ ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | array elements ...
+---------------+---------------+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰┤ ╰─┤
2 bits: forward bits 3 bits: mark bits
string instances
62 bits: vtable pointer 61 bits: forwarding pointer 36 bits: string size
╭───────────────┴──────────────╮╭───────────────┴─────────────╮ ╭───────┴─────────╮
+---------------+---------------+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ ┊ ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ | utf8 bytes ...
+---------------+---------------+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰┤ ╰─┤ ╰───────┬───────╯
2 bits: forward bits 3 bits: mark bits 32 bits: hash code
Traits
trait-boxed instances
62 bits: vtable pointer 61 bits: forwarding pointer
╭───────────────┴──────────────╮╭───────────────┴─────────────╮
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
| ┊ ┊ ┊ | ┊ ┊ ┊ | ┊ ┊ ┊ ┊ ┊ ┊ ┊ | instance ...
+---------------+---------------+---------------+---------------+─ ─ ─ ─ ─ ─ ─ ─
╰┤ ╰─┤
2 bits: forward bits 3 bits: mark bits
Unions
trait-boxed union instances
...reference-based union instances
+---------------+---------------+
| ┊ ┊ ┊ | ┊ ┊ ┊ |
+---------------+---------------+
╰───────────────┬───────────────╯
64 bits: reference or null-pointer