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feat: ##Inf/##-Inf/##NaN literals, infinite?/NaN?, fix intval? for infinity

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The reader now reads the symbolic float values ##Inf, ##-Inf and ##NaN. Added
infinite? and NaN? predicates. Fixed intval? to exclude infinity (floor(inf)=inf
but inf isn't integer-valued), so float?/double? are true for ##Inf and
int?/pos-int?/nat-int?/neg-int? are false for it.

This unblocked many number-test files whose  forms previously failed to
READ (##Inf/##NaN literals), so clojure-test-suite jumped from 2241 to 2539
assertions and pass 1719 -> 1955. Baseline raised to 1900. NaN_qmark now runs.

float?/double? on integer-valued doubles (1.0) remain false: Janet represents
an integer and an integer-valued double identically, so they're inherently
indistinguishable — documented in the README Numbers section.

spec: numbers/floats-&-symbolic-values (15 cases). jpm test green.
Closes jolt-fy8 (fixable parts; int-vs-float ambiguity is a documented divergence).
This commit is contained in:
Yogthos 2026-06-05 09:35:44 -04:00
parent 09532dac05
commit 03652dce5d
6 changed files with 41 additions and 5 deletions
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README.md
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@ -74,7 +74,7 @@ Janet's standard library is reachable through `jolt.interop` (and the `jolt.shel
Jolt targets Clojure semantics but runs on Janet, not the JVM. The notable divergences:
- **Host platform.** No JVM and no Java interop — `import`, `gen-class`, `proxy` of Java classes, and `java.*` are unavailable. `instance?` recognizes a small set of built-in types (`clojure.lang.Atom`, `Number`, `String`, …).
- **Numbers.** Janet integers and doubles. `(/ 1 3)` is `0.3333…` and large products lose precision. No ratios or `BigDecimal` (`ratio?` is always false, `bigdec` falls back to a double); `bigint`/`biginteger` use Janet's 64-bit `int/s64`, not arbitrary precision. The auto-promoting `+'`/`-'`/`*'`/`inc'`/`dec'` are aliases for the plain ops, since Janet numbers don't overflow. `quot`/`rem`/`mod` follow Clojure's sign rules.
- **Numbers.** Janet integers and doubles. `(/ 1 3)` is `0.3333…` and large products lose precision. No ratios or `BigDecimal` (`ratio?` is always false, `bigdec` falls back to a double); `bigint`/`biginteger` use Janet's 64-bit `int/s64`, not arbitrary precision. The auto-promoting `+'`/`-'`/`*'`/`inc'`/`dec'` are aliases for the plain ops, since Janet numbers don't overflow. `quot`/`rem`/`mod` follow Clojure's sign rules. The symbolic values `##Inf`/`##-Inf`/`##NaN` read, and `infinite?`/`NaN?` work. Janet represents an integer and an integer-valued double identically, so `1` and `1.0` are indistinguishable: `(float?/double? 1.0)` is `false` and `(int? 1.0)` is `true` — `float?`/`double?` are true only for values with a fractional part or `##Inf`/`##NaN`.
- **Collections.** By default Jolt uses immutable persistent data structures: vectors are 32-way branching tries (structural-sharing persistent vectors with O(log₃₂ n) `conj`/`assoc`/`nth`), lists are persistent singly-linked cons cells (O(1) `conj`/`cons` prepend with structural sharing), and maps/sets are persistent hash structures. Value equality and sequence operations are Clojure-compatible, but hash-map/hash-set iteration order is unspecified and differs from Clojure — use `sorted-map`/`sorted-set` when order matters.
- **Mutable build mode.** Jolt can be compiled to use fast Janet-native *mutable* collections instead, via a build-time flag: `JOLT_MUTABLE=1 jpm build` (default `jpm build` is immutable). In mutable mode vectors and lists share one mutable array representation (so `conj` mutates in place and appends, and `vector?`/`list?` no longer distinguish them) — a performance/looseness trade-off. The default immutable build has full Clojure value semantics.
- **Concurrency / STM.** Single-threaded. No refs, `dosync`, agents, or `send`; `locking` evaluates its body without real locking. Atoms, volatiles, and delays are supported.