AHTML, an HTML templating and manipulation library

This provides the following features:

• A purely functional HTML element tree abstraction (no mutation of existing elements), with 32-bit id based references out of a specialized region based allocator, allowing efficient allocation and sub-tree re-use without the cost and complications of reference counting.

• A small library of utility functions/methods to map and filter over the tree, allowing efficient purely functional document manipulations (meaning the previous (sub)tree continues to exist).

• An element creation API that is simple enough that no custom language is needed (neither macro nor text-parsing based). I.e. "templating" happens purely via nested method calls of the same name as the elements one wishes to create.

• Correctness checks for element nesting and attribute names (not currently values, and also not checking for the count of particular child elements--e.g. duplicate title elements in the head are not detected, mostly for performance reasons). The checks are done at runtime, not compile time, partially for pragmatism, but also to allow correctness checks when the HTML structure is not determined by Rust source code, but e.g. by parsing HTML out of a Markdown document.

• A pre-serialization feature to convert sub-trees to their HTML string representation and re-use that interpretation in new trees, for performance (although AHTML is really quite performant without making use of that, too).

• An (optional) allocator pool, to make allocation even more efficient via region re-use.

This is an alpha release, and needs proper documentation (TODO).

Debugging

Tracing HTML origin

When the AHTML_TRACE env var is set to a true value or the empty string, every HTML element that doesn't already have a title attribute will gain one that contains a backtrace from the location where the constructor for that element is called. This allows to trace back to the code that generated the element in question. Important: build in debug mode or the backtrace will be useless.