ClojureDart (cljd) port - status

Branch: cljd. Target: compile edamame to Dart so SCI can run on ClojureDart.

Status: all tests pass

Run tests:

clj -M:cljd test edamame.core-test

(Needs Dart SDK >= 3.0. :cljd pins ClojureDart to a git sha and runs in CI via script/test/cljd. For hacking on ClojureDart itself, compose the local checkout: clj -M:cljd:cljd-local test edamame.core-test.)

What is cljd-specific

• Two cljd-only namespaces replace clojure.tools.reader, split so SCI can require the reader types directly (as it does with tools.reader):
  • src/edamame/impl/cljd_reader_types.cljd - self-contained string-backed indexing push-back reader, line/col 1-based, with source logging (readers know their string + index, so :source is a subs). Stands in for clojure.tools.reader.reader-types: the r and rt aliases in parser.cljc and core.cljc point here on cljd, and SCI's parser should too.
  • src/edamame/impl/cljd_shim.cljd - the rest of the tools.reader surface: char/number reading, edn fallback, ns-keys, ReaderConditional deftype with IPrint for :preserve printing. The edn, i, utils and commons aliases in parser.cljc point here on cljd. Call sites stay untouched on all platforms.
• #?(:cljd ...) reader-conditional arms across parser.cljc, core.cljc, syntax_quote.cljc, read_fn.cljc, macros.cljc.
• cljd-shim/list replaces cljd.core/list in parser, read-fn and syntax-quote via :refer-clojure :exclude. Upstream cljd bug: the () literal inside cljd.core/list carries const-folded compiler meta (:line 3436 :tag PersistentList etc) which leaks into every list it builds. Worth reporting to ClojureDart.
• Tests: clj/cljs-only tests are gated with #?(:cljd nil ...) so cljd test discovery skips them. Cljd-specific shields in core_test.cljc:
  • edge-cases-test: Dart RegExp has no inline (?i) flag, uses [Ii].
  • thrown? assertions use cljd.core/ExceptionInfo since cljd ex-info is not a Dart Exception.
  • array-map-test: gated off. ClojureDart has no PersistentArrayMap, so all maps are hash maps and small map literals lose insertion order. ACCEPTED: order is cosmetic for SCI, callers needing it can pass an ordered map constructor via the :map opt. Real fix belongs upstream.

Works (all SCI needs)

numbers, strings, chars, keywords, symbols, colls, location metadata, reader conditionals (incl :default and :preserve printing), syntax-quote, namespaced maps, deref/quote/var/fn-literals, regex via :regex, tagged literals, uneval, :auto-resolve, :source (source-logging reader), edn fallback. No known gaps.

Platform semantics on cljd:

• No Ratio and no BigDecimal in Dart: 1/2 and 3.14M parse as double (like cljs). N suffix parses as Dart BigInt.
• \r\n and \r normalize to \n in the reader, like tools.reader.
• syntax-quote treats ns as a special symbol (unqualified), matching cljs and cljd.reader. The special set follows cljd.reader plus catch, finally and &.

edn fallback

read in cljd_shim.cljd is a minimal tools.reader.edn stand-in. The fallback is only reachable in two cases: ' without the :quote opt (quote is a symbol constituent in edn, reads as a symbol) and dispatch macros disabled by opts (throws "No dispatch macro"). All other dispatch chars are handled by parse-sharp before the catch-all.

cljd.reader (in the ClojureDart repo) was considered as the fallback: it is a full ClojureDart reader with sync read-string and chunked stream support, but it tracks no line/col so it cannot replace edamame parsing, and its semantics diverge from tools.reader.edn ('foo reads as (quote foo) instead of the symbol 'foo), which would make cljd behave differently from clj/cljs.

See also the gotchas: cljd const-folds (Object.) -> use ^:unique; keywords not reference-equal -> kw-identical? uses =; cljd ExceptionInfo is not a Dart Exception (thrown? Exception won't catch ex-info); no array-map; StringBuffer .write returns void; defrecord always emits IPrint so a custom -print needs deftype; cljd.core/list leaks const meta (see above).