Reach full XSLT 1.0 key, numbering, and document parity:
- xsl:key declarations are compiled into an index over the source tree;
the key() function looks nodes up by key name and value.
- format-number() renders a number against a picture string (digit places,
decimal point, grouping, percent), Foundation-free.
- xsl:number generates the context node's position rendered as arabic,
alphabetic, or roman numerals.
- document() resolves an external source through an injected loader so the
transform never reaches the filesystem or network by default.
These hang off an XPath function-table injection mechanism: the evaluator
merges an engine-supplied FunctionTable, letting XSLT register current(),
key(), format-number(), and document() per evaluation.
Closes#63
Compile and evaluate full XPath 1.0 expressions, not just location paths.
Add the four-type Value (node-set, boolean, number, string) with the spec's
coercion rules and canonical number formatting, a recursive-descent parser
for the operator grammar (or/and, equality, relational, additive,
multiplicative, unary minus, union) whose grammatical position disambiguates
* and the operator keywords, function calls, variable references, and filter
expressions. Predicates are now arbitrary expressions (a numeric predicate
is a position test). Comparison follows the node-set quantification rules.
Query gains value/number/string/boolean accessors and a $variable binding
map; the core functions last, position, count, not, true, false, boolean,
number, and string ship with it.
Closes#42
