jolt/host/chez/emit.janet
Yogthos eb26ad0401 Chez Phase 2 (inc I+J): first-class vars + scalar natives
inc I (jolt-n7rz) — vars as first-class objects. (var x)/#'x lowered a
:the-var IR op the Chez emitter didn't handle (57 emit-fails, the biggest
bucket); emit it to the rt.ss var-cell and shim the static var ops in
vars.ss: var?/var-get/deref/var-as-IFn/var =/pr-str (#'ns/name) + a native
bound? (the overlay reads (get v :root), nil on a var-cell record). def now
RETURNS the var (#'ns/name) like Clojure — def-var!/declare-var! yield the
cell, not the value — so (var? (def x 1)) is true and pr-str-of-var/defn
pass (un-allowlisted). Dynamic binding (binding/with-bindings*/var-set/
thread-bound?) stays a follow-up; those crash on nil host prims (safe).
Var def-time metadata (^:private/^Type/doc) isn't captured yet — allowlisted.

inc J (jolt-snry) — scalar natives. natives-misc.ss: a juuid record
(random-uuid v4 / parse-uuid / uuid? / #uuid pr-str / str), a %-format
engine (%d/%s/%.Nf/%x/%c/%%; printf rides on it), a jtagged record
(tagged-literal + :tag/:form + #tag pr-str), bigint/biginteger as
near-identity over the all-flonum model. Overlay names (uuid?/random-uuid/
parse-uuid/tagged-literal?) re-asserted in post-prelude.ss.

Prelude parity 1898 -> 1951, 0 new divergences. Floor raised to 1951.
2026-06-18 15:44:10 -04:00

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# Phase 1 — jolt IR -> Chez Scheme emitter (jolt-cf1q.2).
#
# The new back end: consumes the SAME host-neutral IR (jolt.ir, see
# jolt-core/jolt/ir.clj) the live analyzer produces and the Janet backend
# consumes, but emits Scheme source text instead of Janet. `host/compile` (Chez
# `eval`) turns that into a procedure. Covers the pure-functional + numeric
# subset (const/local/var/host/if/do/let/fn/invoke/def/loop/recur) — enough to
# run fib/mandelbrot-shaped code through the REAL analyzer.
#
# IR access mirrors the Janet backend: live IR fields are jolt VALUES — vectors
# are persistent (pv), and a nil-valued node densifies to a phm. `nn`/`vv` below
# normalize both into Janet structs/arrays, so the same code drives hand-built
# IR (the unit tests) and live analyzer output (the driver).
(import ../../src/jolt/pv :as pv)
(import ../../src/jolt/phm :as phm)
# Normalize a node (phm -> struct) and a vector field (pvec -> array view); both
# pass plain Janet values through untouched, so hand-built IR still works.
(defn- nn [n] (if (phm/phm? n) (phm/phm-to-struct n) n))
(defn- vv [x] (if (pv/pvec? x) (pv/pv->array x) x))
# Hot clojure.core primitives lowered to native Scheme, mirroring the Janet
# backend's native-ops (documented numbers-only relaxation). `=` is the
# exactness-aware jolt= from values.ss; inc/dec/not are rt shims; mod/rem/quot
# map to Scheme's (correct: Scheme has all three, unlike Janet which lacked quot).
(def- native-ops
{"+" "+" "-" "-" "*" "*" "/" "/"
"<" "<" ">" ">" "<=" "<=" ">=" ">="
"=" "jolt=" "inc" "jolt-inc" "dec" "jolt-dec" "not" "jolt-not"
"min" "min" "max" "max"
"mod" "modulo" "rem" "remainder" "quot" "quotient"
# persistent-collection leaf ops (jolt-wgbz) -> rt prims in collections.ss
"vector" "jolt-vector" "hash-map" "jolt-hash-map" "hash-set" "jolt-hash-set"
"conj" "jolt-conj" "get" "jolt-get" "nth" "jolt-nth" "count" "jolt-count"
"assoc" "jolt-assoc" "dissoc" "jolt-dissoc" "contains?" "jolt-contains?"
"empty?" "jolt-empty?" "peek" "jolt-peek" "pop" "jolt-pop"
# seq tier (jolt-5pso) -> rt prims in seq.ss
"first" "jolt-first" "rest" "jolt-rest" "next" "jolt-next" "seq" "jolt-seq"
"cons" "jolt-cons" "list" "jolt-list" "reverse" "jolt-reverse" "last" "jolt-last"
"map" "jolt-map" "filter" "jolt-filter" "remove" "jolt-remove"
"reduce" "jolt-reduce" "into" "jolt-into" "concat" "jolt-concat" "apply" "jolt-apply"
"range" "jolt-range" "take" "jolt-take" "drop" "jolt-drop"
"keys" "jolt-keys" "vals" "jolt-vals"
"even?" "jolt-even?" "odd?" "jolt-odd?" "pos?" "jolt-pos?" "neg?" "jolt-neg?"
"zero?" "jolt-zero?" "identity" "jolt-identity"
# exceptions (jolt-vcsl): ex-info builds the tagged map; ex-data/ex-message/
# ex-cause are pure-over-get Clojure tier fns (no native-op needed).
"ex-info" "jolt-ex-info"})
# Value-position resolution for a clojure.core ref passed AS A VALUE (to map /
# filter / reduce / apply). Each native-op already names a usable Scheme
# procedure; arithmetic is the exception — Scheme's +/-/*// return EXACT results
# for exact/zero-arg inputs, breaking the all-double model in higher-order use,
# so value-position arithmetic routes to the flonum-coercing rt wrappers.
(def- core-value-procs
(merge native-ops {"+" "jolt-add" "-" "jolt-sub" "*" "jolt-mul" "/" "jolt-div"}))
# Per-op arity gate: only lower when the Scheme prim and the jolt fn agree at
# this arity. Ops absent from the table are variadic (arith/compare/=, the
# collection constructors, conj/assoc/dissoc) and legal at any arity.
(def- op-arity
{"inc" |(= $ 1) "dec" |(= $ 1) "not" |(= $ 1)
"count" |(= $ 1) "empty?" |(= $ 1) "peek" |(= $ 1) "pop" |(= $ 1)
"mod" |(= $ 2) "rem" |(= $ 2) "quot" |(= $ 2) "contains?" |(= $ 2)
"get" |(or (= $ 2) (= $ 3)) "nth" |(or (= $ 2) (= $ 3))
"assoc" |(and (>= $ 3) (odd? $)) "dissoc" |(>= $ 1) "conj" |(>= $ 1)
# seq tier arities the shims support
"first" |(= $ 1) "rest" |(= $ 1) "next" |(= $ 1) "seq" |(= $ 1)
"reverse" |(= $ 1) "last" |(= $ 1) "keys" |(= $ 1) "vals" |(= $ 1)
"even?" |(= $ 1) "odd?" |(= $ 1) "pos?" |(= $ 1) "neg?" |(= $ 1)
"zero?" |(= $ 1) "identity" |(= $ 1)
"cons" |(= $ 2) "filter" |(= $ 2) "remove" |(= $ 2) "into" |(= $ 2)
"take" |(= $ 2) "drop" |(= $ 2) "map" |(>= $ 2) "apply" |(>= $ 2)
"reduce" |(or (= $ 2) (= $ 3)) "range" |(and (>= $ 0) (<= $ 3))
"ex-info" |(or (= $ 2) (= $ 3))})
# If fnode is a clojure.core (or host) ref to a native-op primitive, return the
# Scheme op string — only at an arity where the Scheme op and the jolt fn agree.
(defn- native-op [fnode nargs]
(def nm (case (get fnode :op)
:var (when (= "clojure.core" (get fnode :ns)) (get fnode :name))
:host (get fnode :name)
nil))
(def op (and nm (get native-ops nm)))
(def arity-ok (get op-arity nm))
(cond
(nil? op) nil
(and arity-ok (not (arity-ok nargs))) nil
op))
# PRELUDE MODE (inc 3d). The default (subset) mode rejects any clojure.core ref
# that isn't a native-op — a clean "out of subset" signal for user-facing `-e`.
# When emitting clojure.core ITSELF as a Scheme prelude, core fns reference each
# other constantly; those refs must lower to `var-deref` (resolved at runtime
# from the prelude's own def-var! forms) instead of being rejected. Host interop
# (:host) and unhandled IR ops still error in both modes — those are the real
# gaps that need a hand-written RT shim.
(var- prelude-mode? false)
(defn set-prelude-mode! [on] (set prelude-mode? on))
(var- recur-target nil)
# Munged local names known to hold a procedure (a named fn's self-recursion name).
# Calls to these stay DIRECT; any other :local callee routes through jolt-invoke
# (dynamic IFn dispatch) — keeps the fib self-call off the invoke fallback.
(def- known-procs @{})
(var- gensym-n 0)
(defn- fresh-label [prefix] (string prefix (++ gensym-n)))
# Most jolt names are already valid Scheme identifiers (inc, even?, +, ->str all
# are — Scheme allows ! $ % & * + - . / : < = > ? @ ^ _ ~). The one that isn't is
# `#`, which jolt auto-gensyms use as a suffix (e.g. p1__0000X4# from #(...)
# shorthand) — `#` starts a datum in Scheme, so replace it with `_`.
(defn- munge [name] (string/replace-all "#" "_" name))
(var emit nil) # forward declaration (mutual recursion with the helpers below)
# A Chez string literal (jolt-x0os). Janet's %j renders a non-ASCII char as raw
# UTF-8 bytes (\xC3\xA9) and a control char / DEL as \xHH with NO terminating
# semicolon — both forms Chez's reader rejects ("invalid character \ in string
# hex escape"). Emit a Chez string where every byte outside printable ASCII
# becomes a codepoint hex escape \x<cp>; (UTF-8 decoded for multibyte) and the
# named escapes (\n \t \r \" \\) match what both readers accept. For pure
# printable ASCII this is byte-identical to %j.
(defn- utf8-cp [s i]
# decode the UTF-8 sequence starting at byte i -> [codepoint byte-length]
(def b (in s i))
(cond
(< b 0x80) [b 1]
(= (band b 0xE0) 0xC0) [(bor (blshift (band b 0x1F) 6)
(band (in s (+ i 1)) 0x3F)) 2]
(= (band b 0xF0) 0xE0) [(bor (blshift (band b 0x0F) 12)
(blshift (band (in s (+ i 1)) 0x3F) 6)
(band (in s (+ i 2)) 0x3F)) 3]
(= (band b 0xF8) 0xF0) [(bor (blshift (band b 0x07) 18)
(blshift (band (in s (+ i 1)) 0x3F) 12)
(blshift (band (in s (+ i 2)) 0x3F) 6)
(band (in s (+ i 3)) 0x3F)) 4]
[b 1])) # malformed lead byte: pass through one byte
(defn- chez-str-lit [s]
(def out @"\"")
(def n (length s))
(var i 0)
(while (< i n)
(def b (in s i))
(cond
(= b 0x22) (do (buffer/push-string out "\\\"") (++ i))
(= b 0x5C) (do (buffer/push-string out "\\\\") (++ i))
(= b 0x0A) (do (buffer/push-string out "\\n") (++ i))
(= b 0x09) (do (buffer/push-string out "\\t") (++ i))
(= b 0x0D) (do (buffer/push-string out "\\r") (++ i))
(and (>= b 0x20) (< b 0x7F)) (do (buffer/push-byte out b) (++ i))
(< b 0x80) (do (buffer/push-string out (string/format "\\x%x;" b)) (++ i))
(let [[cp len] (utf8-cp s i)]
(buffer/push-string out (string/format "\\x%x;" cp))
(+= i len))))
(buffer/push-string out "\"")
(string out))
(defn- emit-const [v]
(cond
(nil? v) "jolt-nil"
(boolean? v) (if v "#t" "#f")
# jolt models every number as a double (no ratios/bignums; see reader.janet).
# Emit flonums so arithmetic matches the Janet host and Chez doesn't fall into
# exploding exact rationals (mandelbrot). Integer-valued -> append ".0".
# ##Inf/##-Inf/##NaN: Janet stringifies these as inf/-inf/nan, which are
# unbound symbols in Chez — emit Chez's flonum literals instead.
(number? v) (cond
(= v math/inf) "+inf.0"
(= v (- math/inf)) "-inf.0"
(not= v v) "+nan.0"
(let [s (string v)]
(if (or (string/find "." s) (string/find "e" s)) s (string s ".0"))))
(string? v) (chez-str-lit v) # quoted+escaped string literal
# keyword literal -> (keyword ns name); ns is everything before the first "/"
(keyword? v) (let [s (string v) idx (string/find "/" s)]
(if (and idx (> idx 0))
(string "(keyword " (chez-str-lit (string/slice s 0 idx)) " "
(chez-str-lit (string/slice s (inc idx))) ")")
(string "(keyword #f " (chez-str-lit s) ")")))
# jolt char value {:ch <codepoint> :jolt/type :jolt/char}
(and (struct? v) (= :jolt/char (get v :jolt/type)))
(string "(integer->char " (get v :ch) ")")
(errorf "emit-const: unsupported literal %p" v)))
# Quoted literals (jolt-u8j7). A :quote node's :form is the RAW reader form (a
# Janet value): scalars are Janet natives, a symbol is {:jolt/type :symbol …}, a
# list is an array, a vector a tuple, a map a struct/phm, a set a tagged struct.
# Reconstruct each as the matching Chez RT constructor — the runtime value of a
# quote is just that literal data (the interpreter returns the reader form
# verbatim; the Janet backend Janet-quotes it; here we rebuild it on the RT).
(var emit-quoted nil)
(defn- emit-quoted-map [m]
(def flat @[])
(eachp [k v] m (array/push flat (emit-quoted k)) (array/push flat (emit-quoted v)))
(string "(jolt-hash-map " (string/join flat " ") ")"))
(set emit-quoted (fn emit-quoted [form]
(cond
# scalars emit-const already lowers (nil/bool/number/string/keyword/char)
(or (nil? form) (boolean? form) (number? form) (string? form) (keyword? form))
(emit-const form)
(and (struct? form) (= :symbol (get form :jolt/type)))
(let [ns (get form :ns)
m (get form :meta)]
(if (and m (not (nil? m)) (> (length m) 0))
# carry reader metadata (^:foo bar) onto the quoted symbol so (meta 'x) sees it
(string "(jolt-symbol/meta " (if ns (chez-str-lit ns) "#f") " "
(chez-str-lit (get form :name)) " " (emit-quoted m) ")")
(string "(jolt-symbol " (if ns (chez-str-lit ns) "#f") " "
(chez-str-lit (get form :name)) ")")))
(and (struct? form) (= :jolt/char (get form :jolt/type))) (emit-const form)
(and (struct? form) (= :jolt/set (get form :jolt/type)))
(string "(jolt-hash-set " (string/join (map emit-quoted (get form :value)) " ") ")")
(array? form) (string "(jolt-list " (string/join (map emit-quoted form) " ") ")")
(tuple? form) (string "(jolt-vector " (string/join (map emit-quoted form) " ") ")")
(phm/phm? form) (emit-quoted-map (phm/phm-to-struct form))
(or (struct? form) (table? form)) (emit-quoted-map form)
(errorf "emit-quoted: unsupported quoted form %p" form))))
(defn- emit-binding [b]
(def b (vv b))
(string "(" (munge (get b 0)) " " (emit (get b 1)) ")"))
# letfn lowers to a :let flagged :letrec (mutually-recursive named local fns):
# Scheme `letrec*` binds them so each sees its siblings (and itself), which a
# sequential let* can't. A plain let uses let* (Clojure let binds sequentially).
(defn- emit-let [node]
(def kw (if (get node :letrec) "letrec*" "let*"))
(string "(" kw " (" (string/join (map emit-binding (vv (get node :bindings))) " ") ") "
(emit (get node :body)) ")"))
(defn- emit-loop [node]
(def label (fresh-label "loop"))
(def pairs (map vv (vv (get node :bindings))))
(def names (map |(munge (get $ 0)) pairs))
# inits are evaluated in the OUTER scope (recur-target unchanged) and, like
# Clojure loop/let, SEQUENTIALLY — a later init sees earlier bindings. Scheme's
# named `let` binds in parallel, so wrap a sequential let* around the loop.
(def inits (map |(emit (get $ 1)) pairs))
(def seq-bs (string/join (map (fn [n i] (string "(" n " " i ")")) names inits) " "))
(def rebinds (string/join (map (fn [n] (string "(" n " " n ")")) names) " "))
(def prev recur-target)
(set recur-target label)
(def body (emit (get node :body)))
(set recur-target prev)
(string "(let* (" seq-bs ") (let " label " (" rebinds ") " body "))"))
(defn- emit-recur [node]
(unless recur-target (error "emit: recur outside a loop/fn target"))
(string "(" recur-target " " (string/join (map emit (vv (get node :args))) " ") ")"))
# One arity -> a Scheme lambda param-list + a named-let-wrapped body. The named
# let lets fn-level `recur` rebind this arity's params. A variadic arity takes a
# Scheme rest arg (proper list) and the let binding coerces it to a jolt seq
# (nil when empty — Clojure's rest semantics; list->cseq already does this); recur
# carries the rest seq directly, and the named let's init only runs on first
# entry, so the coercion isn't re-applied on a recur.
# try/catch/finally (jolt-vcsl). throw raises the jolt value RAW (jolt-throw =
# Scheme `raise`), mirroring the Janet COMPILED backend (which does `(error v)`,
# no :jolt/exception envelope) — so catch binds the value directly, no unwrap.
# catch lowers to `guard` with an `else` clause (catch-all: the IR drops the
# class), finally to `dynamic-wind`'s after-thunk (runs on success, catch, and
# escape — Clojure finally semantics). Both keys are optional on the node.
(defn- emit-try [node]
(def core
(if-let [cs (get node :catch-sym)]
(string "(guard (" (munge cs) " (else " (emit (get node :catch-body)) ")) "
(emit (get node :body)) ")")
(emit (get node :body))))
(if-let [fin (get node :finally)]
(string "(dynamic-wind (lambda () #f) (lambda () " core ") (lambda () " (emit fin) "))")
core))
(defn- emit-arity-clause [a]
(def params (map munge (vv (get a :params))))
(def restp (when-let [r (get a :rest)] (munge r)))
(def label (fresh-label "fnrec"))
(def prev recur-target)
(set recur-target label)
(def body (emit (get a :body)))
(set recur-target prev)
(def paramlist
(cond
# only a rest param: Scheme formals are the bare symbol, not `( . xs)`
(and restp (empty? params)) restp
restp (string "(" (string/join params " ") " . " restp ")")
(string "(" (string/join params " ") ")")))
(def binds
(if restp
[;(map (fn [p] (string "(" p " " p ")")) params)
(string "(" restp " (list->cseq " restp "))")]
(map (fn [p] (string "(" p " " p ")")) params)))
[paramlist (string "(let " label " (" (string/join binds " ") ") " body ")")])
(defn- emit-fn [node]
(def arities (map nn (vv (get node :arities))))
# a named fn binds its own name as a known-procedure local across ALL arities,
# so self-calls (to any arity) emit directly rather than via jolt-invoke; the
# case-lambda value dispatches on argument count.
(def self (when-let [nm (get node :name)] (munge nm)))
(def had-self (and self (get known-procs self)))
(when self (put known-procs self true))
# Restore known-procs even when a body is uncompilable: a throw mid-emit must
# not leak this fn's name into the module global, or a LATER case binding the
# same name to a keyword/coll would emit a direct call to a non-procedure
# (runtime crash). The corpus probe shares one emit state across all cases, so
# this leak is order-dependent and otherwise invisible in single-case tests.
(def clauses
(try (map emit-arity-clause arities)
([err fib]
(unless had-self (when self (put known-procs self nil)))
(propagate err fib))))
(unless had-self (when self (put known-procs self nil)))
(def lambda
(if (= 1 (length clauses))
(let [[pl body] (first clauses)] (string "(lambda " pl " " body ")"))
(string "(case-lambda "
(string/join (map (fn [c] (string "(" (get c 0) " " (get c 1) ")")) clauses) " ")
")")))
# A named fn (defn / (fn self [..])) references itself by name — the analyzer
# binds that name as a :local in the body. letrec makes the name visible to the
# lambda so self-calls resolve (recur stays a separate self-call to the arity).
(if-let [nm (get node :name)]
(let [m (munge nm)] (string "(letrec ((" m " " lambda ")) " m ")"))
lambda))
# The Clojure stdlib (clojure.core, clojure.math, clojure.string, …) and host
# interop (Math/sqrt etc.) have no implementation on Chez yet (Phase 2+). A
# reference to one — except a clojure.core call lowered to a native op — is
# genuinely uncompilable here. Reject it at emit time (a clean "out of subset"
# signal) rather than emitting a var-deref that resolves to nil and fails
# confusingly at runtime.
(defn- stdlib-var? [n]
(and (= :var (get n :op)) (string/has-prefix? "clojure." (or (get n :ns) ""))))
# Host interop methods with a Chez RT shim (rt.ss jolt-host-call). A `.method`
# call on any other method is out of subset until shimmed — keep this in sync.
(def- supported-host-methods {"write" true "isDirectory" true "listFiles" true})
# jolt's comparison ops are vacuously true at arity 1 and DON'T inspect the arg
# (so (< :kw) is true), but Scheme's < demands a number even there — special-case.
(def- cmp1-ops {"<" true ">" true "<=" true ">=" true})
# IFn dispatch for a LITERAL callee (Clojure's "value as fn"): a keyword looks
# itself up in its arg ((:k m) = (get m :k)); a map/set/vector literal looks up
# its arg ((m :k) = (get m :k)). This static lowering avoids the jolt-invoke
# dispatch overhead; the dynamic case (a local holding a keyword/coll/fn) routes
# through jolt-invoke in the emit-invoke fallback below.
(defn- ifn-kind [fnode]
(case (get fnode :op)
:const (when (keyword? (get fnode :val)) :keyword)
:map :coll :set :coll :vector :coll
nil))
(defn- emit-invoke [node]
(def fnode (nn (get node :fn)))
(def args (map emit (vv (get node :args))))
(def nop (native-op fnode (length args)))
(def kind (ifn-kind fnode))
(def default (if (> (length args) 1) (string " " (in args 1)) ""))
(cond
# zero-arg + / * : Scheme's identity is the EXACT 0 / 1, but jolt models every
# number as a double, so emit the flonum identity to keep (= 0 (+)) true.
(and nop (empty? args) (= nop "+")) "0.0"
(and nop (empty? args) (= nop "*")) "1.0"
(and nop (= 1 (length args)) (get cmp1-ops nop)) (string "(begin " (first args) " #t)")
nop (string "(" nop " " (string/join args " ") ")")
# (:k coll [default]) -> (jolt-get coll :k [default])
(= kind :keyword) (string "(jolt-get " (first args) " " (emit fnode) default ")")
# (coll k [default]) -> (jolt-get coll k [default])
(= kind :coll) (string "(jolt-get " (emit fnode) " " (first args) default ")")
(and (stdlib-var? fnode) (not prelude-mode?))
(errorf "emit: unsupported stdlib fn `%s/%s` (no core on Chez yet)" (get fnode :ns) (get fnode :name))
(= :host (get fnode :op))
(errorf "emit: unsupported host call `%s` (no host interop on Chez yet)" (get fnode :name))
# a :local callee that isn't a known procedure (a let/param binding holding a
# keyword/coll/fn) -> dynamic IFn dispatch. Excludes the named-fn self-call.
(and (= :local (get fnode :op)) (not (get known-procs (munge (get fnode :name)))))
(string "(jolt-invoke " (emit fnode) " " (string/join args " ") ")")
# a late-bound :var call head can hold a plain procedure OR a non-applicable
# value the RT dispatches (a multimethod record, a keyword/coll IFn) — route it
# through jolt-invoke so all of those work. Transparent for a procedure
# (jolt-invoke just applies it); the hot self-recursive call is a :local
# known-proc above, so it stays a direct call.
(= :var (get fnode :op))
(string "(jolt-invoke " (emit fnode) " " (string/join args " ") ")")
# a computed callee (an :invoke / :if / :do expression) can yield ANY IFn —
# a procedure, but also a coll/keyword/multimethod (e.g. ((sorted-map …) k)).
# Route through jolt-invoke: transparent for a procedure, correct for the rest.
(string "(jolt-invoke " (emit fnode) " " (string/join args " ") ")")))
# Native-op Scheme procedures that return a genuine Scheme boolean (#t/#f), so an
# :if test built from them needs no jolt-truthy? wrapper (jolt-nkcb). Comparisons
# and `not` are #t/#f; the numeric/collection predicates bottom out in fx=?/>/etc.
(def- bool-returning-ops
{"<" true "<=" true ">" true ">=" true "jolt=" true "jolt-not" true
"jolt-even?" true "jolt-odd?" true "jolt-pos?" true "jolt-neg?" true
"jolt-zero?" true "jolt-empty?" true "jolt-contains?" true})
# Does this IR node emit to an expression that yields a Scheme boolean? Used to
# drop the redundant jolt-truthy? on an :if test — sound because jolt-truthy? of
# #t/#f is the identity. Conservative: only a boolean const or an :invoke that
# lowers to a bool-returning native op (any other shape keeps the wrapper).
(defn- returns-scheme-bool? [node]
(def node (nn node))
(cond
(and (= :const (get node :op)) (boolean? (get node :val))) true
(= :invoke (get node :op))
(let [nop (native-op (nn (get node :fn)) (length (vv (get node :args))))]
(truthy? (and nop (get bool-returning-ops nop))))
false))
(set emit (fn emit [node]
(def node (nn node))
(case (get node :op)
:const (emit-const (get node :val))
:local (munge (get node :name))
# late-bound var: read the cell's current root at use time. A value-position
# ref to a clojure.core fn the RT provides (e.g. passing `inc`/`even?`/`:k` to
# (map inc xs)) lowers to the RT procedure — native-ops names a real Scheme
# procedure for each. Any OTHER stdlib var (clojure.string, an unimplemented
# core fn) has no impl on Chez yet, so it's out of subset.
:var (let [core-proc (and (= "clojure.core" (get node :ns)) (get core-value-procs (get node :name)))]
(cond
core-proc core-proc
(and (stdlib-var? node) (not prelude-mode?))
(errorf "emit: unsupported stdlib ref `%s/%s` (no core on Chez yet)" (get node :ns) (get node :name))
(string "(var-deref " (chez-str-lit (get node :ns)) " "
(chez-str-lit (get node :name)) ")")))
:host (errorf "emit: unsupported host ref `%s` (no host interop on Chez yet)" (get node :name))
# (var x) / #'x -> the var cell itself (the rt.ss var-cell, a first-class var
# object). var?/var-get/deref/invoke/= operate on it (vars.ss).
:the-var (string "(jolt-var " (chez-str-lit (get node :ns)) " " (chez-str-lit (get node :name)) ")")
:if (let [test (get node :test)
t (if (returns-scheme-bool? test) (emit test)
(string "(jolt-truthy? " (emit test) ")"))]
(string "(if " t " " (emit (get node :then)) " " (emit (get node :else)) ")"))
:do (string "(begin "
(string/join (map emit (vv (get node :statements))) " ")
(if (empty? (vv (get node :statements))) "" " ")
(emit (get node :ret)) ")")
:invoke (emit-invoke node)
# collection literals -> rt constructors (collections.ss)
:vector (string "(jolt-vector " (string/join (map emit (vv (get node :items))) " ") ")")
:set (string "(jolt-hash-set " (string/join (map emit (vv (get node :items))) " ") ")")
:map (let [flat @[]]
(each p (vv (get node :pairs))
(def p (vv p))
(array/push flat (emit (get p 0)))
(array/push flat (emit (get p 1))))
(string "(jolt-hash-map " (string/join flat " ") ")"))
:let (emit-let node)
:loop (emit-loop node)
:recur (emit-recur node)
:throw (string "(jolt-throw " (emit (get node :expr)) ")")
:try (emit-try node)
:quote (emit-quoted (get node :form))
# regex literal #"…" -> a jolt-regex value (regex.ss compiles the source via
# the vendored irregex). chez-str-lit quotes+escapes the source; a backslash
# in the pattern becomes \\ in the Scheme string literal -> the 1-char
# backslash irregex expects (same escaping emit-const uses for strings).
:regex (string "(jolt-regex " (chez-str-lit (get node :source)) ")")
# host interop (jolt-0kf5): (.method target arg*) -> (jolt-host-call "method"
# target arg*). Only the methods the RT dispatcher (rt.ss) actually shims are
# IN the subset; any other method is out of subset (a clean emit-time reject,
# like an unimplemented stdlib fn), so it doesn't masquerade as a compiled-but-
# broken divergence. The Janet back end punts ALL :host-call to the interpreter.
:host-call (let [m (get node :method)
target (emit (get node :target))
args (map emit (vv (get node :args)))]
(if (get supported-host-methods m)
(string "(jolt-host-call " (chez-str-lit m) " "
target (if (empty? args) "" (string " " (string/join args " "))) ")")
# a non-shimmed method: dispatch at runtime by the target's type
# — a record/reify protocol method (jolt-jgoc). On a non-record
# host value this errors (was an emit-fail before, so no new
# divergence), but it lets (.protoMethod record …) compile.
(string "(record-method-dispatch " target " " (chez-str-lit m)
" (jolt-vector" (if (empty? args) "" (string " " (string/join args " "))) "))")))
:fn (emit-fn node)
# (def name) with no init (declare): reserve the var cell (declare-var!
# doesn't clobber an existing root) so a forward reference resolves.
:def (if (get node :no-init)
(string "(declare-var! " (chez-str-lit (get node :ns)) " "
(chez-str-lit (get node :name)) ")")
(string "(def-var! " (chez-str-lit (get node :ns)) " "
(chez-str-lit (get node :name)) " " (emit (get node :init)) ")"))
(errorf "emit: unhandled op %p" (get node :op)))))
# Wrap emitted top-level forms into a runnable Chez program: load the RT, then
# the def forms, then print `final` (an emitted Scheme expr string) via jolt's
# number/value printing.
(defn program [forms-scheme final]
(string
"(import (chezscheme))\n"
"(load \"host/chez/rt.ss\")\n"
(string/join forms-scheme "\n") "\n"
"(printf \"~a\\n\" (jolt-final-str " final "))\n"))