v0.15.0

Install or upgrade:

curl -fsSL https://x2c-lang.dev/install.sh | sh

Releases ship for macOS arm64 and x86_64 and Linux aarch64 and x86_64, with
the book as a PDF beside the archives. Read
Upgrading from 0.14.0
before replacing an existing prefix.

Language

• meta functions run ordinary x2c during translation. A macro body calls
  one with $helper(...), passes constants or captured syntax, and inserts
  the code it returns. meta.x supplies the Code and Type operations
  for inspecting and building code. See
  Meta Functions and
  Generating Code.
• Macro values: a macro can select, apply, and collect cases as values,
  and typed quotations with expression holes build code with its type.
• Stmt macros accept an expression body, and a macro call may begin with
  a dotted name.
• Module blocks split one translation unit across a directory. The new
  module storage class is visible in every member file; static stays
  private to its file.
• Indentation syntax: a .xp file, or #pragma indent in a .x file,
  groups statements by indentation without braces or semicolons. See
  Indentation Syntax.
• raise is a statement head, catch accepts patterns as codes, and a
  variable may supply a raise code.
• Optional reference parameters, GNU statement expressions, threaded
  thread-local storage, and the contextual in membership operator.
• class types gain alloc and a refusing init, and init takes
  constructor arguments.
• Twelve language features moved out of the compiler kernel into
  components under src/components/; their behavior is unchanged.

Library

• lib/regex.x adds regular expressions over the bytes of a String, and
  every x2c script can use them.
• lib/diff.x computes line differences between two texts.
• The runtime's canonical pool operations moved from List to Pool.
• Var.truth replaces Var.truthy; List.reduce, Array.reduce, and
  Iter.reduce are removed in favor of Iter.foldl.
• Compile-time Lisp gains tail calls and a bounded call depth.

Commands and packages

• x2c new creates a starter project that builds and runs.
• x2c repl is a shipped command with line editing, grammar-aware and
  semantic completion, and named inspection of session values. It
  evaluates a supported subset of the language. See
  Experimental REPL.
• Package management, the editor adapter, and project creation are
  external commands under libexec/x2c/. x2c lint and x2c graph are
  shipped as experimental.
• Packages record native arguments in <name>.native.rsp instead of
  <name>.link. Rebuild source packages and replace native bundles.
• Automatic differentiation moved from the runtime to the optional
  autodiff package; import "autodiff" supplies its types and macros.
• The SQLite package renames Statement to Prepared and
  Var.statement to Var.prepared.
• Every package manages its handles with $auto, so connections, loops,
  images, documents, and terminals release at scope exit.
• The C* verification package is removed.

Documentation

• The book adds the x2c Syntax Map for C
  readers, the syntax specifications with a source
  grammar and lexical rules, The Region Model, and
  chapters for meta functions, generating code, the REPL, and indentation.
• The language reference was corrected against the implementation and
  its repeated rules removed.
• The public site at x2c-lang.dev carries the
  book under /docs/.

Fixed defects

• A return inside a defer or finally body leaves its exception frame
  before transferring, so a later raise in the caller is caught.
• Macro bindings retained across package builds, nested empty unit
  macros, quotation members and splices, and template members in
  anonymous aggregates expand correctly.
• Parameter redeclaration inside callable bodies and the author-binding
  extern regression are fixed.
• Constructed raw string segments, nested string literals inside list
  literals, and negative percent literals in every radix are read as
  written.
• Pointer arithmetic over pointer typedefs and casts to template typedefs
  type correctly.
• Project meta payloads, include handling, the failure cache, and host
  flags are repaired for package builds.

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Source 3149948; candidate candidate-314994819f7fad4f4d97c6df9cf622aa7edec575-38995554323-1.