TuneC: a written tune becomes the bytes the player reads

The compiler, and the last thing the ladder was waiting for. A tune names
its instruments, writes sequences of notes and durations, and gives each
voice an order list of sequence names - which is where repetition comes
from, since a phrase played four times is written once and named four
times.

  #Tick 0d125000
  #Patch Oboe oboe.patch
  #Voice 0d0 Oboe
  #Sequence Verse
    0d64 0d4  0d67 0d4  0d72 0d8
  #Order 0d0
    Verse Verse Ending

"#" is a directive and ";" is a comment, exactly as in SplitBit assembly
and in the shell's scripts, and numbers are written the way the assembler
writes them. One rule across the machine rather than a third dialect -
and the rule earned itself immediately: the first tune I wrote said
"#Voice 0" and was refused, correctly, for a bare number.

WHAT IT REFUSES IS EVERYTHING THE PLAYER CANNOT NOTICE. The machine has
no names, so it cannot say a sequence does not exist. It has no lengths,
so it cannot say the voices will come apart four bars after the mistake.
A duration of nought is counted down to 255 and held, which sounds like a
hang rather than an error. And by the time a tune is loaded, "no starting
instrument" and "instrument nought" are the same byte - so the user's
ruling, that a voice with a part and no instrument is an error, can only
be kept here.

SoundPatch gains --blob, writing the same table as raw bytes. It stays
the only thing that reads soundThing's JSON: a second program parsing
that format is a second opinion about what a patch means, and the seam
between two opinions is where the LFO bug lived for a fortnight. Patches
are found beside the tune and then on a -I path, the way an include is.

THE TEST IS THAT TWO IMPLEMENTATIONS AGREE. maketune.py lays the fixture
out by hand and TuneC compiles a written source, and the suite checks
they match byte for byte - the discipline SplitDisk and sbfs.asm are held
to, for the same reason: either alone is only self-consistent. The
fixture predates the compiler, so this is also TuneC checked against
something written before it existed. Four more checks cover the four
refusals.

Also: the SoundPatch binary was tracked, alone among the six tools, and
.gitignore lists every other one. Untracked, and TuneC added beside it.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW

Tests/makedisks.sh

@@ -713,6 +713,29 @@ printf 'system /System/Boot/cosmos.bin\n' > "$WORK/lonely.cfg"
 # directory listing that ten recorded tests quote.
 python3 "$ROOT/Tests/maketune.py" "$WORK/two.tune" >/dev/null
 "$TOOL" put "$DISKS/quiet.img" "$WORK/two.tune" two.tune >/dev/null
+
+# ---- And the same tune, written down and compiled ----
+#
+# TWO IMPLEMENTATIONS OF ONE FORMAT, which is the discipline SplitDisk and sbfs.asm are held
+# to: maketune.py lays the bytes out by hand and TuneC compiles a written source, and the
+# suite checks that they agree byte for byte. Either one alone would only be self-consistent.
+#
+# The patches are SoundPatch's, in the raw form TuneC embeds. Two blobs differing in one
+# parameter, the octave, so the same note number sounds an octave apart.
+"$ROOT/SoundPatch" --blob "$ROOT/Programs/Sounds/Oboe.json" Low "$WORK/low.patch" >/dev/null
+python3 - "$WORK/low.patch" "$WORK/high.patch" <<'FIXTURE'
+# The fixture patches are written here rather than converted, because what they have to be is
+# two patches identical but for the octave - which is a fact about the test and not about any
+# instrument anybody designed.
+import sys
+def blob(octave):
+    pairs = [(0x00, 2), (0x01, 0xFF), (0x05, 1), (0x20, 0),
+             (0x21, 0), (0x22, 0xFF), (0x23, 5), (0x04, octave)]
+    return bytes([len(pairs)]) + b"".join(bytes(p) for p in pairs)
+open(sys.argv[1], "wb").write(blob(128))
+open(sys.argv[2], "wb").write(blob(129))
+FIXTURE
+"$ROOT/TuneC" -I "$WORK" "$ROOT/Programs/Tunes/two.tune.txt" "$WORK/compiled.tune" >/dev/null
 "$ROOT/Assembler" -I "$ROOT/Programs/Sounds" -I "$ROOT/Programs/Libraries" \
     -I "$ROOT/Programs/CosmOS/Source" \
     "$ROOT/Programs/CosmOS/Apps/Play.asm" -o "$WORK/Play.sbx" >/dev/null