Squint dev notes

Build / watch

• User keeps bb dev running (shadow-cljs watch on the squint build, :output-dir "lib"). It recompiles lib/ on every save of a .cljc/.cljs source. Don't run bb build (full release): it does fs/delete-tree "lib" then a shadow release, which can leave lib/ missing and break bb dev (runs node_cli.js, needs lib/cli.js).
• bb dev is a never-ending watch task. It prints Build completed once after startup (~20s) then keeps watching. If you start it yourself, kill it after that line.
• Verify compiler changes by grepping the emitted lib/cljs-runtime/*.js chunk (e.g. lib/cljs-runtime/squint.compiler.js) for the new code.

Emission

• Emit each form once. Never emit a form as a probe and then emit it again, not even on a fallback path. Re-emission repeats side effects, advances gensyms and doubles per nesting level: an and chain of n operands ending in recur emitted the recur 2^n times under a probe.
• Decide from the form, the env or the context before emitting, or reuse the emitted text.

Adding a core stdlib fn

Needs THREE steps (e.g. dedupe):

1. export function in src/squint/core.js.
2. Add the munged name (e.g. dedupe, foo_QMARK_) to resources/squint/core.edn. This list is the set of vars the compiler prefixes with squint_core.. A var NOT in core.edn emits as a BARE identifier (no prefix) -> runtime ReferenceError, with no compile-time warning (no-warn-on-unresolved is by design for now).
3. Recompile lib/. core.edn is inlined at compile time by the edn-resource macro (slurp at macroexpand, see resources/squint/resource.clj), so editing the edn alone does nothing until the shadow watch rebuilds lib/cljs-runtime/squint.compiler.js.

Transducer-capable fns follow the arguments.length === 0 -> return xform pattern (see filter/distinct and their *1 helpers). Use _EQ_ for value equality (deep), not ===.

Data representation

• Keywords are plain JS strings: :foo/bar -> "foo/bar". No distinct keyword type, so keyword?/symbol?/namespace are absent by design. name exists.
• Maps are JS objects; keys are strings. Boolean/number map keys get stringified (lossy): (get m false) != (get m "false").