HYPOTHESIS (Will's): a compiler whose one compiled mechanism is extending the
LANGUAGE — not the compiler — can compose without recompilation.
ISHIKAWA — why does a construct require a recompile today?
method codegen inlines the target call into the body
machine the binary has no table to consult
material the declaration lives in source, read at compile time
measurement nothing observes what applied at runtime
root cause the crossing is resolved at EMISSION, not at EXECUTION
CHANGE: codegen emits one unconditional indirection per fn. Which constructs
apply is read from a table that can be written AFTER the binary exists;
targets resolve through dlsym against the running image.
PREDICTIONS AND RESULTS
P1 a construct declared after the build applies TRUE
P2 an unlinked target is skipped, not fatal TRUE
P3 emitting on every fn is measurably slower FALSE — 0.37s -> 0.36s
with 267 indirections and
no bindings. Free unused.
P4 the compiler still self-hosts TRUE (see note)
DEMONSTRATED: an El program with NO decorator in its source, already compiled
and linked, picked up a construct declared afterwards:
$ /tmp/seamrun -> 7
$ echo 'work audited entry audit_entry' > constructs.txt
$ EL_CONSTRUCTS=constructs.txt /tmp/seamrun
AUDIT: work applied by audited
7
P4 note: my first fixpoint test was wrong, not the code. I compared gen1 to
gen2, which must differ whenever codegen's output changes. gen2 == gen3, 267
seam sites, stable.
MEASURED COST, and the root cause was not where I looked
0 bindings 0.36s vs 0.37s baseline free
2 bindings, dlsym per call 2.45s 6.6x
2 bindings, resolved once 0.69s 3.5x recovered
The table scan was never the cost. dlsym walks the dynamic symbol table on
every call. Resolve once and cache — which is the smallest form of what
salience does for memory: what is hot stays resolved. The 0.69s residual is
audit_entry's own printf on two of the compiler's hottest functions, not seam
overhead.
CONSEQUENCE: the five compile-time declaration kinds on iteration-1 are a
compile-time specialisation of something that resolves at runtime. They are not
wrong, but they are not the mechanism — the mechanism is one indirection, and a
kind is data.
bigmerge
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