Version “26.0” released 2026-02-10

Version numbering scheme changed: the first number corresponds to the year of the version. The number after dot is the rank of this version in the year (starting from 0).

This version principally enhances STklos performance: compiler is faster and, some Scheme primitives have been rewritten in C, several numerical primitives have been optimized (thanks to Jerônimo Pellegrini). As usual a bunch of new SRFIs have been implemented.

Contributors for this version:

• Jerônimo Pellegrini (@jpellegrini)
• Retropikzel (@Retropikzel)

Enhancements

• Globally, everything is a bit faster:

  • some often used list primitives have been rewritten in C
  • Scheme object allocation uses now a pool of pre-allocatted cells
  • compiler is faster

• STklos can be compiled with -std=c23

• Reader:

  • Accept the Common Lisp syntax for complex numbers
  • Accept symbols with a leading sharp character
  • Use can define new read directives
  • new directives #!uvector-syntax and #!no-uvector-syntax to allow/forbid the reading of unifom vectors.
  • Skip characters until end of line when an error occurs in the REPL to avoid cascading errors.
  • the behaviour of the reader can be customized when an opening angle bracket (or curly brace) is encountered.

• VM:

  • added specialized instruction for pair? testing
  • added new instruction for if without else

• eval can now evaluate an expression in a local (rather global) environment

• Correct/enhance implementation of numerical functions in some corner cases (in particular with NaNs and infinities).

• functions in R7RS libraries can be auto-loaded

• Syntax:

  • implement ellipsis escaping
  • implementation enhancement of let-syntax and define-syntax
  • syntax-rules returns now a matching function
  • implement vector patterns in syntax-rules
  • change: syntax value cannot be used in an expression
  • all fundamental forms are now syntax and can be redefined as required by R⁷RS (they were special forms before)
  • let-syntax accepts Scheme syntax as wall as Lisp like macros.

• describe has been extended to give better information on certain object types

• FFI:

  • code has been enhanced and should be more secure.
  • fixed precision problem between float and double
  • permit to access array elements

• Compiler

  • some new optimizations
  • enhanced the code rewriter.

• Added support for the R7RS-large library (scheme rlist)

Extensions

• GTklos extension (GTK+ bindings)
  • a documentation has been added
  • code rewriting and widgets are more coherent
  • deleted GTK+ deprecated properties
  • Library paths are guessed for system which do not install libraries in standard places

New primitives / parameter objects:

• pair-immutable!
• c-size-of
• cpointer-ref
• cpointer-set!
• cpointer-ref/abs
• cpointer-set/abs!
• symbol-interned?
• compiler-current-port
• includes-use-load-path
• readline-startup-hook
• readline-set-option!
• readline-bind!
• compiler:verify-assume
• accept-uvector-syntax
• define-read-directive
• read-bracket-handler
• read-brace-handler

Updated embedded libraries

• libffi updated to version 3.5.2
• pcre2 updated to version 10.46
• libgc updated to version 8.2.12

New supported SRFI

• SRFI-101: Purely Functional Random-Access Pairs and Lists
• SRFI-234: Topological Sorting
• SRFI 239: Destructuring Lists
• SRFI-253: Data (Type-)Checking
• SRFI-225: Dictionnaries
• SRFI-258: Uninterned symbols
• SRFI-260: Generated Symbols
• SRFI-264: String Syntax for Scheme Regular Expressions

Misc:

• Updated documentation
• Better error messages
• Added tests
• Code cleaning and optimizations
• Bug fixes

Version “2.10” released 2024-10-10

This version of STklos mostly enhances the 2.00 version released a year ago. As usual, this version could not have be finalized without the help of Jeronimo Pellegrini (@jpellegrini).

Contributors for this version:

• Akinori Hattori (@hattya)
• Jeronimo Pellegrini (@jpellegrini)

Enhancements:

• Corrected the result of stklos-config --compile
• Added the second (optional) parameter to R7RS load (and try-load)
• Enhanced various things about STklos compilation/installation
• Added information in the summary of configuration script
• Builds are now reproducible
• FFI support can be completely disabled, if needed.
• Updated GTklos, the GTK+ extension
• Optimize expt primitive.
• Avoid unneeded boxing of numbers in the +, -, * and / operations
• Added ! as a shell escape under the REPL
• Added statistics to the VM
• Permit to build STklos with the tcc C compiler.
• Added an simple hybrid (C and Scheme) module in the examples directory
• Correct/enhance implementation of numerical functions in some corner cases (in particular with NaNs and infinities).
• Added an API to add expressions rewriting rules before their compilation.
• Location given in error message is more precise
• Error messages don’t loop anymore when displaying circular structures
• Added list-set! as the setter function of list-ref
• Added the number of allocations and collections to the output of the time form
• Added special instructions in the VM for member, memq and memv
• Added special instructions in the VM for assoc, assq and assv
• Do constant folding before in-lining usual functions
• Better UTF-8 support and updated Unicode tables to version 16.0.0
• Enhance the apropos primitive
• New REPL variables: @*, @1, @2, @3, @4 and @5
• New REPL commands: time, describe, expand, import, require-feature, open, browse, manual, apropos
• Documentation of a function can be accessed directly into the HTML Reeference Manual
• Length of symbols is no more limited.

New primitives / parameters:

• read-ci
• eval-form-string-ci
• read-from-sring-ci
• compiler:source-rewrite
• compiler:peephole-optimizer
• 1+ and 1-
• push! and pop
• inc! and dec!
• dolist
• apropos/alist
• apropos/pp
• default-browser
• open-in-browser
• manual
• install-path
• define-parameter

Updated embedded libraries

• libgc updated to version 8.2.8
• libffi updated to version 3.4.6
• libpcre2 updated to version 10.44

New supported SRFI

• SRFI-115: Scheme Regular Expressions
• SRFI-178: Bitvector library
• SRFI-232: Flexible curried procedures

Misc:

• Updated documentation
• Added tests
• Code cleaning an optimizations
• Bug fixes

Version “2.00” released 2023-09-12

This is a major version of STklos, bringing it from R⁵RS to R⁷RS. It is the fruit of nearly two years of development with the help of the following persons (in alphabetical order):

• Amirouche Boubekki (@amirouche)
• Lassi Kortela (@lassik)
• Ivan Maidanski (@ivmai)
• Tom Niget (@zdimension)
• Jeronimo Pellegrini (@jpellegrini)
• Ryan Schmidt (@ryandesign)
• Ben Taca (@bentaca)
• Robby Zambito (@Zambito1)

The main changes in this version are:

• Support for R⁷RS libraries
• Macro system has been rewritten
• Support for ScmPkg packages has been suppressed
• New options for the commands stklos(1) and stklos-compile(1)
• Optimizations on numerical operations
• Documentation is rewritten in asciidoctor and has been greatly enhanced
• Updated the Docker build files
• New instructions in the VM
• Fixed some issues in the compilation/installation procedure
• New extension: curl to access the multiprotocol file transfer library
• Better support for macOS
• describe has been enhanced for some type of objects
• REPL has now tab completion
• Bash and zsh completions for stklos and stklos-compile commands
• Better SLIB support
• Use PCRE2 library instead of legacy PCRE
• New-command stklos-pp(1)
• Better error messages
• New SRFIS supported
  • SRFI-19: Time Data Types and Procedures
  • SRFI 43: Vector Library
  • SRFI-95: Sorting and Merging
  • SRFI 116: Immutable List Library
  • SRFI 125: Intermediate hash tables
  • SRFI-138: Compiling Scheme programs to executables
  • SRFI 152: String Library (reduced)
  • SRFI-162: Comparators sublibrary
  • SRFI 154: First-class dynamic extents
  • SRFI-215: Central Log Exchange
  • SRFI 217: Integer Sets
  • SRFI 222: Compound objects
  • SRFI 224: Integer Mappings
  • SRFI-227: Optional Arguments
  • SRFI 228: Composing Comparators
  • SRFI-229: Tagged Procedures
  • SRFI-230: Atomic Operations
  • SRFI 235: Combinators
  • SRFI 236: Evaluating expressions in an unspecified order
  • SRFI-238: Codesets
  • SRFI 244: Multiple-value Definitions
• Added support for some R7RS-large libraries
  • supported libraries of the Red edition are
    • (scheme bytevector)
    • (scheme box)
    • (scheme charset)
    • (scheme comparator)
    • (scheme generator)
    • (scheme hash-table)
    • (scheme ideque)
    • (scheme ilist)
    • (scheme list)
    • (scheme list-queue)
    • (scheme lseq)
    • (scheme set)
    • (scheme sort)
    • (scheme stream)
    • (scheme text)
    • (scheme vector)
  • supported libraries of the Tangerine edition are
    • (scheme bitwise)
    • (scheme bytevector)
    • (scheme division)
    • (scheme fixnum)
    • (scheme flonum)
    • (scheme generator)
    • (scheme vector @)
• New primitives
  • library-name
  • library-list
  • module-list
  • module-lock!
  • module-locked?
  • symbol-mutable?
  • define-constant
  • cpointer-null?
  • syntax-error
  • hash-table-clear!
  • environement
  • send-signal
  • set-signal-handler!
  • get-signal-handler
  • void?
  • procedure-source
  • procedure-formals
  • short-version
  • radians->degrees
  • degrees->radians
  • sinh, cosh, …
• New compiler options (also parameter objects):
  • compiler:gen-line-number
  • compiler:show-assembly-code
  • compiler:time-display
  • compiler:keep-formals
  • compiler-keep-source
  • compiler:inline-common-functions
  • compiler:unroll-iterations
  • repl-show-startup-message
• New predefined classes
  • <uvector>
  • <bytevector>
  • <hash-table>
  • <port>
  • <input-port>
  • <output-port>
• Code cleaning an optimizations
• Added tests
• Bug fixes