docs: archive the frozen stage code as one compressed tarball

docs/history kept six stages with a full copy of the project under code/,
3.8 mb of sources duplicated from stage to stage and already superseded. store
them as docs/history/code-snapshots.tar.gz, 0.66 mb, and extract one in place
to read it. every stage's notes.md stays browsable, and the index says where the
code went and how to get it back.

the top-level README points at the archive too. its other two links into
docs/history, 21-micro and 35-bench, were notes that were never kept and do not
resolve; the index now records that.

8 files changed, 0 insertions, 152 deletions

diff --git a/docs/history/13-gap-fixes/code/examples/echo.zc b/docs/history/13-gap-fixes/code/examples/echo.zc
deleted file mode 100644
index 01f28b0..0000000
--- a/docs/history/13-gap-fixes/code/examples/echo.zc
+++ /dev/null
@@ -1,2 +0,0 @@
-// everything after the backtick is left unread, for the program itself
-fn main() { while (!eof()) putc(getc()); return 0; }
diff --git a/docs/history/13-gap-fixes/code/examples/fact.zc b/docs/history/13-gap-fixes/code/examples/fact.zc
deleted file mode 100644
index 2a218b2..0000000
--- a/docs/history/13-gap-fixes/code/examples/fact.zc
+++ /dev/null
@@ -1,4 +0,0 @@
-fn fact(n) { if (n < 2) return 1; return n * fact(n - 1); }
-// prints in binary, like the old asm example
-fn bin(n) { if (n > 1) bin(n >> 1); putc('0' + (n & 1)); return 0; }
-fn main() { bin(fact(10)); putc(10); putn(fact(10)); putc(10); return 0; }
diff --git a/docs/history/13-gap-fixes/code/examples/hello.zc b/docs/history/13-gap-fixes/code/examples/hello.zc
deleted file mode 100644
index f36a810..0000000
--- a/docs/history/13-gap-fixes/code/examples/hello.zc
+++ /dev/null
@@ -1 +0,0 @@
-fn main() { puts("hello, world!\n"); return 0; }
diff --git a/docs/history/13-gap-fixes/code/examples/lists.zc b/docs/history/13-gap-fixes/code/examples/lists.zc
deleted file mode 100644
index 6ac276e..0000000
--- a/docs/history/13-gap-fixes/code/examples/lists.zc
+++ /dev/null
@@ -1,35 +0,0 @@
-// ownership in practice: a list owns its boxes. nothing here calls free;
-// everything is released at the end of the block that owns it.
-fn box(v) -> .u { let b = new(1); b[0] = v; return u*b; }
-fn mklist(cap) -> .u { let l = new(cap + 1); l[0] = 0; return u*l; }
-// item m*arrives (it was given down), and goes d*on into the borrowed list
-fn push(.m l, .d item) { l[l[0] + 1] = d*item; l[0] = l[0] + 1; return 0; }
-fn show(.m l)
-{
-	let i = 1;
-	putc('[');
-	while (i <= l[0]) { if (i > 1) putc(' '); putn(l[i][0]); i++; }
-	putc(']');
-	return 0;
-}
-fn squares(n) -> .u
-{
-	let l = mklist(n), i = 0;
-	while (i < n) {
-		let b = box(i * i);
-		push(l, d*b);
-		i++;
-	}
-	return u*l;
-}
-fn main()
-{
-	let before = live_objects();
-	{
-		let l = squares(6);
-		show(l); putc(10);
-		puts("live: "); putn(live_objects() - before); putc(10);
-	}
-	puts("after the block: "); putn(live_objects() - before); putc(10);
-	return 0;
-}
diff --git a/docs/history/13-gap-fixes/code/examples/repl.zc b/docs/history/13-gap-fixes/code/examples/repl.zc
deleted file mode 100644
index b7b81b8..0000000
--- a/docs/history/13-gap-fixes/code/examples/repl.zc
+++ /dev/null
@@ -1,27 +0,0 @@
-// a repl on the resident compiler: each backtick-separated chunk of input is
-// compiled as a function body and run. definitions (fn ...) can be loaded too:
-// a chunk that starts with "fn" goes through load instead of eval.
-let buf[4000];
-fn readchunk()
-{
-	let n = 0, c;
-	while (!eof()) {
-		c = getc();
-		if (c == 96) break;
-		if (n < 3999) { buf[n] = c; n++; }
-	}
-	buf[n] = 0;
-	return n;
-}
-fn main()
-{
-	let q, i;
-	while (!eof()) {
-		readchunk();
-		q = tokens(buf);
-		if (q[0] && q[1] == T_ID && q[2] == intern("fn")) load(q);
-		else eval(q);
-		free(d*q);
-	}
-	return 0;
-}
diff --git a/docs/history/13-gap-fixes/code/examples/selfpatch.zc b/docs/history/13-gap-fixes/code/examples/selfpatch.zc
deleted file mode 100644
index 074ccec..0000000
--- a/docs/history/13-gap-fixes/code/examples/selfpatch.zc
+++ /dev/null
@@ -1,17 +0,0 @@
-// code is data: find the literal 'A' inside f's compiled words and rewrite it.
-// on the jit the store lands on translated code, which gets dropped and
-// retranslated on the next call.
-fn f() { putc('A'); return 0; }
-fn litw(v) { return v + v + 1; }	// how the vm encodes a literal push
-fn main()
-{
-	let p = f;
-	f();
-	while (*p != litw('A')) p++;
-	*p = litw('B');
-	f();
-	*p = litw('C');
-	f();
-	putc(10);
-	return 0;
-}
diff --git a/docs/history/13-gap-fixes/code/examples/typed.zc b/docs/history/13-gap-fixes/code/examples/typed.zc
deleted file mode 100644
index d91fe6a..0000000
--- a/docs/history/13-gap-fixes/code/examples/typed.zc
+++ /dev/null
@@ -1,47 +0,0 @@
-// types: structs, a generic container, and looking at it all through reflection
-typecheck on;
-struct point { int x, y; };
-struct vec<T> { int len, cap; *T items; };
-
-fn mkvec<T>(int cap) -> *vec<T>.u
-{
-	*vec<T> v = new(vec<T>);
-	v.cap = cap;
-	v.items = new(T, cap);
-	return u*v;
-}
-// x is given away (.d): the vector's memory holds it from now on, and the
-// collector looks after it
-fn push<T>(*vec<T> v, T.d x) -> bool
-{
-	if (v.len == v.cap) { free(d*x); return 0; }
-	v.items[v.len] = d*x;
-	v.len++;
-	return 1;
-}
-fn show(word t)
-{
-	let i = 0;
-	tprint(t); puts(" is "); putn(tsize(t)); puts(" words: ");
-	while (i < tnfields(t)) { if (i) puts(", "); puts(tfname(t, i)); puts(" "); tprint(tftype(t, i)); i++; }
-	putc(10);
-	return 0;
-}
-fn main() -> int
-{
-	*vec<*point> v = mkvec<*point>(4);
-	int i = 0;
-	while (i < 3) {
-		*point p = new(point);
-		p.x = i; p.y = i * i;
-		push(v, d*p);
-		i++;
-	}
-	puts("last: "); putn(v.items[2].y); putc(10);
-	show(typeof(point));
-	show(typeof(*v));
-	puts("push is "); tprint(sigof(push)); putc(10);
-	// generic code is compiled once, so what mkvec stamped is vec<T>
-	puts("the heap says v is a "); tprint(typeof_obj(v)); puts(", and v.items[0] is a "); tprint(typeof_obj(v.items[0])); putc(10);
-	return 0;
-}
diff --git a/docs/history/13-gap-fixes/code/examples/wiring.zc b/docs/history/13-gap-fixes/code/examples/wiring.zc
deleted file mode 100644
index ed30935..0000000
--- a/docs/history/13-gap-fixes/code/examples/wiring.zc
+++ /dev/null
@@ -1,19 +0,0 @@
-// virtual enhancements: custom opcodes wired into the cpu while compiling.
-// the recipes run through the core's optimizer; the jit inlines the result.
-enhance popcount(x) micro
-	"r1 = shr x 1; r1 = and r1 0x55555555; x = sub x r1"
-	"; r1 = shr x 2; r1 = and r1 0x33333333; x = and x 0x33333333; x = add x r1"
-	"; r1 = shr x 4; x = add x r1; x = and x 0x0f0f0f0f; x = mul x 0x01010101; x = shr x 24";
-enhance div10(x) micro "x = udiv x 10";		// becomes a multiply-high, no divide
-enhance hypot2(a, b) vm { 0 $ * ~ 0 $ * + };	// lifted from vm code
-enhance minmax(a, b) -> 2 micro "r2 = min a b; r1 = max a b; r0 = r2";
-let lo, hi;
-fn main()
-{
-	putn(popcount(0xff00ff)); putc(' ');
-	putn(div10(12345)); putc(' ');
-	putn(hypot2(3, 4)); putc(' ');
-	asm { 9 4 minmax hi ! lo ! }
-	putn(lo); putc('/'); putn(hi); putc(10);
-	return 0;
-}