v0.8.0

This release makes Document a complete API for building and editing formulas. Every node kind now has a constructor, so a formula can be built from scratch as a tree and serialized, and every construction and edit is checked against the document's knowledge base, so the result always conforms to it, as parser output does, and transforms accept it. Deterministic edits, rooted node paths, cross-document imports, and a columnar export cover targeted edits and bulk analysis. To support this, KnowledgeBase becomes an immutable object shared by parsers, engines, and documents. The release also fixes script, text-argument, and declaration-scope handling in alignments and text mode. The knowledge base and construction changes are breaking; see Changed for migration notes.

Changed

• Breaking: Package selection, custom items, and removals move from parser and engine builders to KnowledgeBaseBuilder, and knowledge queries move from Parser and TransformEngine to KnowledgeBase. Build one KnowledgeBase and pass it to every parser, engine, and document that should interoperate, for example Parser::builder().knowledge_base(kb.clone()).build() and TransformEngine::builder().knowledge_base(kb). ParserBuilder::build() now returns Parser, and ParserBuildError and Error::ParserBuild are removed. TransformEngine::transform accepts any document bound to the same instance and returns Error::KnowledgeBaseMismatch otherwise, replacing Error::ForeignDocument. In Python, pass texform.KnowledgeBase(packages, items=...) to Parser(kb) and TransformEngine(profile, kb); in JavaScript, pass { knowledgeBase }. The command-line tool and the serve protocol are unchanged.
• Breaking: Construction, edits, and syntax imports keep every complete document conformant to its knowledge base. A violation returns ConformanceError with a rooted path and a stable rule code (TexformConformanceError in JavaScript) and leaves the document unchanged. Replace ArgValue with Arg, and binding argument dictionaries with Node | str | bool | None | Paired values ({ value, open, close } pairs in JavaScript). create_group and create_environment take their children and body directly, binding delimiters are strings such as "(" and "\\langle", and environments are renamed with set_env_name instead of set_command_name. Document::from_syntax rejects non-conformant complete trees, with FromSyntaxError::Conformance replacing the prime-specific variants, and KnowledgeBaseBuilder rejects item names the lexer cannot produce with KnowledgeBaseBuildError::InvalidName.

Added

• Every node kind has a constructor, including scripted nodes, infix commands, primes, inline math, and delimited groups. Commands and environments are built from their knowledge-base records, so optional, star, and paired slots can be filled, and a constructor called with a name of another command kind names the one to use. Arguments are given as nodes, source text parsed in the slot's mode, star Booleans, or explicit absent and paired values; in_mode and parse_fragment construct in an explicit context mode.
• Deterministic edits: set_subscript and set_superscript add, change, or clear scripts, collapsing the wrapper when the last script is cleared; set_delimiters, set_arg_delimiters, and set_prime_count change delimiters and prime counts. clone_node copies a subtree within a document, and import_node copies one from another document, validating it against the destination knowledge base. Failed edits leave the document unchanged.
• NodeRef::path returns a node's rooted path and Document::node_at resolves it; NodeRef::slot and NodeRef::is_known report the parent slot and knowledge status. Python and JavaScript expose the same edits and reads, JavaScript adds argKind(index), and argument reads include their slot form.
• Document::to_columnar exports a document as a preorder node table and an argument table for Arrow and DataFrame tools (to_columnar() in Python, toColumnar() in JavaScript); Python tables pass directly to pyarrow.table.
• KnowledgeBase instances are cheap to clone and compare by identity (KnowledgeBase::ptr_eq); KnowledgeBase::default() returns one process-wide instance, and Document::with_knowledge_base and Document::from_syntax_with bind an explicit one. Python and JavaScript expose KnowledgeBase with identity equality and hashing, document copies (copy() in Python, clone() in JavaScript), node identity, and document() on nodes.

Fixed

• In alignments, a script directly after a column separator (&^2, &_1, &') now starts the next cell with an empty base instead of using & as its base. Escaped \& still takes scripts.
• An unbraced argument of a text-mode command takes a single token, as in TeX and MathJax: \mbox TeV parses as \mbox{T}eV instead of \mbox{TeV}. \text{$x$ } and \textbf{ \emph k } now parse.
• Alignment separators (&, \\, \newline, \cr) end declarative scopes in environment bodies and math arguments, so \begin{array}{cc} \rm a & b \\ c & d \end{array} lowers to \mathrm{a} & b \\ c & d instead of the invalid \mathrm{a & b \\ c & d}, and a \displaystyle repeated in a later cell is kept.