Joseph Ferano
a4c6b996ff
The trio the author decided on 2026-09-20 is now all built: def is CL's defparameter — its initialiser runs on every daemon re-run, unguarded, so an edited initialiser repaints the same storage on C-c C-c plus re-run — defonce (Clojure's name for CL's defvar, per the author) initialises once behind the .init~once. flag, and defconst stays the image. One parse arm reads both forms; the difference is Ast.reinit, carried to Tast.global's grerun. Emit.startup_plan gives a def no guard flag, and Check.check_global lifts every def initialiser — zero and literal included — into global/<n>, so the host's startup reaches it through the function cell and a re-evaluated def swaps it (Session's def_inits; Emit.redefinition declares the cell for a non-sibling target). The old defvar spelling is refused with the rename and both compiling spellings, and every program, test, doc and editor list is swept — except sand.flan, the author's live WIP, whose seven defvar lines are flagged in FIX.org and keep its three dependent tests red on this branch.
76 lines
3.2 KiB
Plaintext
76 lines
3.2 KiB
Plaintext
;;;; The third element of a defonce, both ways.
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;;;;
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;;;; The rule, 2026-09-20: a type there is the zeroed static global it has
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;;;; always been, and anything else is a dyn global initialised from that
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;;;; expression at startup. So this file is one program holding both kinds
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;;;; side by side, and every line it prints is a claim about which reading
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;;;; one of its declarations got.
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;;;;
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;;;; There is no new lowering under any of it. The dyn half is exactly what
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;;;; [(defonce x dyn <expr>)] already compiled to — the initialiser lifted into
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;;;; the startup function that main calls after the runtime is up, and a
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;;;; collector root pushed for the global before it runs — which is why this
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;;;; program runs identically on both backends and why neither of them
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;;;; learned anything for it.
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(defstruct Point [x i32 y i32])
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;; ── The type reading, which is every declaration that worked before ──
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;; A primitive, a fixed array, a struct and a container: all four are types in
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;; the third position, so all four are the zeroed statics they were.
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(defonce current-color i32)
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(defonce grid [2 [3 u32]])
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(defonce origin Point)
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(defonce bytes (Vec u8))
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;; ── The value reading, which is the new spelling ─────────────────────
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;; None of these names a type, so each is a dyn global holding the value its
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;; expression produced before the program's own code ran.
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(defonce score 0)
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(defonce label "start")
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(defonce config {:level 1 :name "one"})
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(defonce tally seeded)
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;; A call, which is the shape the author kept writing: the file is read once,
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;; at startup, into a global that outlives main.
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(defn load [] dyn {:rows 3 :cols 4})
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(defonce game-data (load))
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;; And the value the bare symbol above was initialised from, declared *below*
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;; it on purpose: which reading a defonce gets is decided with every name in
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;; hand, not in the order the file was written.
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(defonce seeded i64 7)
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(defn main [] ()
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;; The statics, untouched: zero, zero, zero, and an empty Vec that is a real
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;; empty Vec rather than a placeholder.
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(print current-color) (print " ") (print (at grid 1 2)) (print " ")
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(print (.x origin)) (print " ") (print (len bytes)) (println "")
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;; The dyn globals, as their initialisers left them.
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(print score) (print " ") (print label) (print " ")
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(print (get config :name)) (print " ") (print tally) (println "")
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(print (get game-data :rows)) (print " ") (print (get game-data :cols))
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(println "")
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;; They are globals and not constants: each is assigned, and the map is
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;; mutated in place through the same root the startup function filled.
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(set score (+ score 5))
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(set label "done")
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(put config :level 2)
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(set current-color 3)
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(set (at grid 1 2) 9)
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;; An allocation loop between filling them and reading them back, so the
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;; collector runs with the run's own frames on the stack. A dyn global whose
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;; root was not pushed reads back as a stale word here rather than as what
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;; was stored.
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(dotimes [i 20000]
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(let [junk {:i i :s "forty-seven bytes of text to fatten each row"}]
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(put config :seen (get junk :i))))
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(print score) (print " ") (print label) (print " ")
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(print (get config :level)) (println "")
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(print current-color) (print " ") (print (at grid 1 2)) (println ""))
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