briantrice/slate-language

The Slate programming language

Source code at GitHub http://www.slatelanguage.org

{
  "createdAt": "2009-02-02T23:10:29Z",
  "defaultBranch": "master",
  "description": "The Slate programming language",
  "fullName": "briantrice/slate-language",
  "homepage": "http://www.slatelanguage.org",
  "language": "C++",
  "name": "slate-language",
  "pushedAt": "2023-10-15T23:03:27Z",
  "stargazersCount": 149,
  "topics": [
    "environment",
    "language",
    "lisp",
    "macros",
    "multimethods",
    "programming-language",
    "prototypes",
    "smalltalk"
  ],
  "updatedAt": "2025-11-03T10:47:53Z",
  "url": "https://github.com/briantrice/slate-language"
}

Information for the Slate Distribution

What is Slate?

Slate is a prototype-based, multi-dispatch object-oriented language that runs from a highly-customizable live environment. The implementation is highly portable and relatively lightweight.

Where do I learn more?

The reference site for this Distribution is at http://www.slatelanguage.org and the Google Code project at: http://code.google.com/p/slate-language/

Bug reports and requests for information can be made via the Slate mailing list, described at: http://groups.google.com/group/slate-language

See the wiki for more detailed documentation: http://code.google.com/p/slate-language/w/list

See our bug-tracker for issues: http://code.google.com/p/slate-language/issues/list

Copyright/License Information

In short, MIT-style Public License. See the LICENSE file.

Obtaining Slate

To get a slate repository on your computer to play with, run: git clone git://github.com/briantrice/slate-language.git

You must download a Slate image snapshot from Google Code: http://code.google.com/p/slate-language/downloads/

Setup

‘make’ builds the VM. ‘make edit’ launches the VM and standard image in Emacs with a scratch area. ‘(sudo) make install’ installs the VM and images in global directories (/usr/local/ by default) so that the VM can be invoked as just “slate”. ‘make plugins’ builds the plugins that you need for the GUI and FFI-related stuff.

Read common.mk for more options.

Command Line

./slate -i <image>

This starts slate using the save-heap snapshot named .

Run slate -h for more details.

Learning Slate

Read the online tutorials (from newest to oldest):

Bootstrapping

If you make changes to core slate files (like adding a new field to CompiledMethods), sometimes the only easy way to implement those changes throughout the system is to rebuild Slate completely. Here is how you generate a new kernel image:

From the shell:

make bootstrap WORD_SIZE=64 && make slate.image WORD_SIZE=64

or make bootstrap WORD_SIZE=32 && make slate.image WORD_SIZE=32

From within Slate:

At the Slate REPL, execute: load: ‘src/mobius/init.slate’. then: Image bootstrap &littleEndian: True &bitSize: 32. or Image bootstrap &littleEndian: True &bitSize: 64.

Then you will load the resulting kernel image like a regular image:

./slate -i kernel.new.<endian>.<wordsize>.<timestamp>.image

After the image is loaded, you will want to save it so you don’t have to go through loading the kernel again:

Image saveNamed: 'slate.image'.

The same steps can also be accomplished with: make slate.image

Debugging Slate Code

Within the REPL, if an error arises, a debugger prompt will appear: slate[1]> foo. Debugging: MethodNotFound traitsWindow The following condition was signaled: The method #foo was not found for the following arguments: {(previousREPLMethod)}

Available Restarts:
restart: 0  Abort evaluation of expression
restart: 1  Quit Slate

Enter 'help.' for instructions.
slate-debug[0..1][frame: 0]>

Type in help. to see other commands or restart: 0. or just 0. to escape usually.

Debugging the VM

make vmclean && make DEBUG=1
gdb slate
r -i <image-file>
(on crash or Ctrl-c)
bt
f <n> (change frame to one with an 'oh' object (struct object_heap*))

See the slate backtrace -> print print_backtrace(oh) Inspect an object -> print print_detail(oh, struct Object*) See the stack -> print print_stack_types(oh, 200)

Build flags (e.g. make vmclean && make DEBUG=1 EXTRACFLAGS="-DGC_BUG_CHECK -DSLATE_DISABLE_METHOD_OPTIMIZATION -DSLATE_DISABLE_PIC_LOOKUP"):

GC_BUG_CHECK: extra features for debugging the GC

GC_INTEGRITY_CHECK: check all the object memory to make sure it looks good after a GC

SLATE_DISABLE_METHOD_OPTIMIZATION: Don’t optimize methods after calling them a lot. Right now it sets method->oldCode to the current code. In the future it should do inlining.

SLATE_DISABLE_PIC_LOOKUP: At the call site in the current method there is a cache of called functions which is checked after the global cache when doing method dispatch.

SLATE_DISABLE_METHOD_CACHE: Disable the global cache when doing method dispatch.

SLATE_USE_MMAP: Use mmap to allocate the object memory. You should be able to get constant pointers between runnings so that you can debug by learning memory addresses from previous runs.

PRINT_DEBUG and the many PRINT_DEBUG_*: Print more verbose output to the console.

ALWAYS_FULL_GC: Never do a new-generation garbage collection.

GC_MARK_FREED_MEMORY: Mark freed memory with 0xFE in case someone tries to use it again. (Slow)

See the source for more.

Source directory structure

Under src:

vm: The C files for the VM. Interprets bytecode and provides necessary facilities for primitives, gc, etc.
mobius: The slate files for the compiler, lexer, bootstrap, and close-to-vm? facilities etc.
core: The core libraries for the default slate system.
lib: The standard but optional libraries.
plugins: C code for slate FFI calls. `make plugins’ to build
ui: The slate UI code that probably calls plugins to draw the basics. load: ‘src/ui/init.slate’.
ui/gtk: The slate GTK interface. load: ‘src/ui/gtk/demo.slate’.
net: The slate networking code. load: ‘src/net/init.slate’.

Finding source code

Besides using grep, there are a few facilities:

#as: implementations do: [|:each| each definitionLocation ifNotNilDo: [|:l| inform: (l as: String) ]].

(#parseExpression findOn: {Syntax Parser}) definitionLocation

See the slate manual for more details.