Recount at 2.2% once the eight bool predicates convert

The port landed on andrew/akbasic as libakstdlib-26, and converting the eight
sites the first count wrote off moves the figure from 301/13 to 313/7 --
2.2% bypassed on the same tree, against 86.4% before the port.

Those eight were the whole of #38, which asked this library for a form a bool
predicate could call. That was ruled invalid: a function which cannot report
an error changes its own signature instead. Seven did, and the eighth is a
bsearch(3) comparator whose signature libc fixes, so it has nowhere to put an
out parameter. Record that the wrapper shape was right and the consumer's
signatures were wrong, because the first count assumed the opposite.

What is genuinely left is six snprintf sites that want truncation as an
answer -- #34 -- and the comparator, which nothing tracks. #38 attributed it
to akbasic #14; that is a mis-citation and #14 is an unrelated issue.

Correct the call profile for the new total, and note two findings the port
produced rather than measured: a file descriptor leak in akbasic's DLOAD,
caught by the ATTEMPT/CLEANUP rule the conversion forced somebody to obey,
and a latent collision in its host-type registration.

Refs #26, #38

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

README.md

@@ -181,8 +181,9 @@ would notice.
 
 ## Testing
 
-There are four harnesses. The first three take seconds; the fourth takes about
-half an hour.
+There are five harnesses. The first three take seconds and the fifth is instant;
+the fourth takes about half an hour. The fifth is the only one that measures
+something outside this repository.
 
 ### 1. The test suite
 
@@ -469,6 +470,41 @@ right-leaning tree would have blown the stack the depth cap exists to protect),
 and `aksl_tree_remove` on an empty tree, which without its guard dereferences
 NULL. Both are in the suite now — which is what the harness is for.
 
+### 5. Consumer adoption
+
+Coverage says the tests reach the code and mutation testing says they would
+notice it breaking. Neither says anybody *wanted* the code. That question only has
+an external answer, so there is a harness for it too:
+
+```sh
+scripts/consumer_calls.py ../akbasic/src                     # the ratio
+scripts/consumer_calls.py ../akbasic/src --detail --per-file # where it comes from
+scripts/consumer_calls.py ../akbasic/src --baseline 313/7    # against a past count
+```
+
+It counts, across a consumer's source directory, how often that consumer calls
+this library against how often it reaches past it to the libc function this
+library wraps. Calls to libc functions **not** wrapped here — `isdigit`, `exit`,
+`qsort` — score on neither side; the question is how often an *available* wrapper
+gets bypassed. Comments and string literals are stripped before counting, and the
+wrapped-libc set is read out of `include/akstdlib.h` rather than hardcoded, so a
+recount after a release measures the surface that release actually shipped.
+
+A wrapper nobody calls either does not fit or is not discoverable, and both are
+this library's problem rather than the consumer's. `TODO.md` carries the standing
+figures and what they did and did not justify.
+
+Two warnings, both learned the hard way and both printed by `--baseline`:
+
+- **A rate is only comparable between two counts of the same tree.** If the
+  consumer grew between them, compare the percentage and say which commit each
+  number came from. Comparing the totals across a tree that tripled in size is how
+  a real improvement gets reported as a regression, or the reverse.
+- **One consumer's ratio is evidence, not a plan.** A consumer that draws
+  everything from fixed pools will never call the allocator however good the
+  allocator is. Weight the result by what the consumer is, and get a second
+  consumer before treating any ranking as settled.
+
 ## The pre-push hook
 
 `.githooks/pre-push` runs the fast harnesses — the default build and the

TODO.md

@@ -22,6 +22,7 @@ it has been through grooming.
 | Function coverage | 100% (154/154) |
 | Doxygen | 100% of 154, gated — `cmake --build build --target docs` fails on an undocumented function, parameter or return |
 | Mutation score | 72.3% (188/260 sampled from 1701), gated at 65 |
+| Consumer adoption | akbasic ported onto 0.2.0 calls this library 313 times and raw libc 7 — **2.2% bypassed**, from 92.2% at first count. Ungated, and one consumer only |
 
 The six confirmed defects that used to head this file are fixed and
 `AKSL_KNOWN_FAILING_TESTS` is empty. What they were, and what changed as a result,
@@ -102,15 +103,16 @@ are fixed: the right child's `depth + 1` in the depth-first walk, and
 
 ## Evidence from the first full consumer
 
-`akbasic` (`source.starfort.tech/andrew/akbasic`) is a ~6,300-line C interpreter
-built on this library and `libakerror`. It was the first consumer to exercise the
-whole surface rather than a corner of it, **and what it could not use is what
-prioritised everything that has been built since.**
+`akbasic` (`source.starfort.tech/andrew/akbasic`) is a C interpreter built on this
+library and `libakerror` — ~6,300 lines of `src/` when it was first measured,
+20,169 now. It was the first consumer to exercise the whole surface rather than a
+corner of it, **and what it could not use is what prioritised everything that has
+been built since.**
 
 **The number that started it.** Across `src/`, akbasic made **10 calls into this
-library and 116 to raw libc** — a library whose value proposition is "turn silent
-libc failures into error contexts", bypassed 92% of the time by the consumer most
-committed to it.
+library and 119 to raw libc** — a library whose value proposition is "turn silent
+libc failures into error contexts", bypassed **92%** of the time by the consumer
+most committed to it.
 
 | Raw libc it had to use | Count | Now available as |
 |---|---|---|
@@ -121,8 +123,17 @@ committed to it.
 | `strncpy` | 15 | `aksl_strncpy` |
 | `strtoll` / `strtod` | 2 | `aksl_strtoll` / `aksl_strtod` |
 | `fgets` | 2 | `aksl_fgets` |
+| `strncmp` | 1 | `aksl_strncmp` |
+| `memmove` | 1 | `aksl_memmove` |
 | `strstr` | 1 | `aksl_strstr` |
 
+Two corrections to that figure, both found by rebuilding it. It used to read 116;
+the table it sat above summed to 117 and had no row for `strncmp` or `memmove`.
+119 is what `scripts/consumer_calls.py` returns against akbasic `4e188b2`, and it
+is the number everything below compares to. **The method is now a script rather
+than a paragraph, because recovering it afterwards cost more than writing it down
+would have.**
+
 **All four things the port had to write for itself now exist here.**
 
 1. **A strict `strtoll`/`strtod` wrapper** (`akbasic/src/convert.c`, ~60 lines). The
@@ -144,8 +155,138 @@ committed to it.
 the sign-extended djb2 reads bytes unsigned; and the missing `va_end` — which
 akbasic's stdio text sink ran on every line of program output — is fixed.
 
-**Still true, and still shaping the wishlist.** akbasic uses no allocator, no lists
-and no trees, drawing everything from fixed pools by design. **A consumer that does
-allocate would weight the `open`/`read`/`write` work far higher than this one
-does**, so one consumer's count is evidence, not a plan. Re-counting against this
-release is #26.
+### The recount, against this release
+
+akbasic's `src/` was ported onto 0.2.0 and counted again (#26). The port builds
+clean at `-Wall -Wextra`, passes **112/112** of akbasic's ctest suite, and is
+ASan+UBSan-clean.
+
+| | libakstdlib | raw libc | bypassed |
+|---|---|---|---|
+| Baseline — akbasic `4e188b2`, 5,679 lines of `src/` | 10 | 119 | **92.2%** |
+| Before the port — akbasic `330d731`, 20,169 lines | 45 | 285 | **86.4%** |
+| **After the port — same tree** | **313** | **7** | **2.2%** |
+
+**Read the third row against the second, not the first.** The tree tripled between
+the baseline and the port, so 10/119 and 45/285 are counts of two different
+programs; only 86.4% → 2.2% is a like-for-like measurement. The 45 in the middle
+row is worth its own note — akbasic had already adopted `aksl_f*` across
+`runtime_disk.c` on its own, without anybody counting.
+
+**Nothing was blocked by a missing wrapper.** Every libc call akbasic makes had an
+`aksl_*` counterpart. 278 of the 285 sites converted; the 7 that did not are
+blocked by wrapper *shape*, and they are the useful output:
+
+| Why it could not be used | Sites | Where |
+|---|---|---|
+| Truncation is the answer, not the error | 6 | `runtime.c` `akbasic_runtime_error`, `host.c` (×3), `runtime_struct.c` (×2) |
+| A `bsearch(3)` comparator, whose signature libc fixes, so there is no out parameter to report through | 1 | `verbs.c` `verb_compare` |
+
+**The eight sites that used to head this table are gone, and how they went is the
+finding.** They were the `bool` predicates and `void` helpers with no error channel
+to route into, and the first filing (#38) asked this library for a form they could
+call. Andrew ruled that invalid: a function that cannot report an error changes its
+own signature rather than being handed a way to swallow one. Seven of the eight did
+exactly that — they now return `akerr_ErrorContext *` and hand the answer back
+through an out parameter, one of them (`akbasic_environment_is_waiting_for` and its
+sibling) as a public header change. Four more functions on the same call chains
+(`scanner.c` `peek` and `match_next_char`, `sink_akgl.c` `putchar_at`, `echo_line`
+and `edit_key`) had to move with them. **The wrapper shape was right and the
+consumer's signatures were wrong**, which is not what the first count assumed.
+
+The truncation six are a contract decision rather than an accident, and they are
+what is genuinely left. The sharpest is `akbasic_runtime_error` — the one function
+that tells the user *what went wrong*, formatting a 12,384-byte error message into
+a 512-byte line. Truncating a report there is correct; raising `AKERR_OUTOFBOUNDS`
+would replace the diagnosis with a second, different failure. Two more are
+truncation-tolerant renderers that print what fits and stop, one of which reads
+`snprintf`'s return value to *detect* the truncation and skip the rest of the
+render. The remaining three read host-supplied strings into fixed fields.
+
+Two of those three, in `akbasic/src/host.c`, are a latent defect the port surfaced
+rather than a decision: a host-registered type name over 31 characters truncates
+silently, and two names sharing a 31-character prefix then collide in
+`akbasic_structtype_find` — where `structtype.c` refuses the identical case
+outright with a limit message. The two registration paths disagree. That is
+akbasic's to fix, and it is flagged at the site.
+
+### What the recount found, and where it went
+
+Every blocked site came back to wrapper *shape* rather than a missing wrapper, and
+the same seven shapes recurred across ten independent conversion passes. They are
+filed, not listed here:
+
+| Finding | Filed as |
+|---|---|
+| `aksl_snprintf`'s `count` out-param is required, so ~20 sites carry an `int written` that is written and never read. Raised by all ten passes. `-Wall -Wextra` cannot see it — `&written` is a use | #32 |
+| No equality comparison. All 43 comparison sites flatten the three-way `int` to `== 0`; not one wants an ordering, and five now need a sentinel whose *initial value is load-bearing* | #33 |
+| No truncating format and no length query, which is the whole of the truncation-six above and the only shape still blocking a conversion | #34 |
+| `aksl_hashmap_*` carries one payload, which is the only reason `akbasic/src/symtab.c` still exists | #35 |
+| `aksl_fgets` signals end of input by raising, so a read loop cannot be a condition | #36 |
+| A caller cannot add its own context to a wrapper's error, so it raises and discards instead — eight lines where there were two | #37 |
+| No form a `bool` predicate or a `void` function can call, which was 8 of the 13 sites the first count could not convert. **Ruled invalid** — the consumer changes its own signature, and now has | #38 |
+
+**#38 is the one worth reading, because it is the one that was wrong.** It asked
+this library to grow a form a `bool` predicate could call, and the answer was that
+a predicate which cannot report an error should stop returning `bool`. Seven of its
+eight sites converted on that basis, and they are why the count is 2.2% and not 4.1%.
+The `ctype.h` half of the same filing is settled too: `isspace`, `isdigit`,
+`isalnum` and `toupper` cannot fail, so there is nothing for a wrapper to return
+and no reason to add one. What a caller does need is the `(unsigned char)` cast
+every correct `ctype.h` call takes, and that is akbasic's note to keep, not this
+library's.
+
+The `bsearch` comparator has **no issue of its own**. #38 attributed it to akbasic
+`#14`, which is a mis-citation — that issue is the `COLLISION`/`BUMP` pairing
+threshold. Converting the comparator means dropping `bsearch(3)` for an in-house
+binary search that can propagate, on a lookup that runs once per scanned
+identifier, and that wants filing against akbasic before anybody does it.
+
+**The one thing the wrappers did better than the libc they replaced** is worth
+recording next to the complaints: `aksl_fgets`'s `len_out` **deleted** two `strlen`
+calls rather than converting them, and is more correct than what it replaced for a
+line containing an embedded NUL. It is the only one of 278 conversions that
+produced less code than it started with.
+
+**The port also found a defect in akbasic rather than in this library.** `DLOAD`
+leaked a file descriptor: its read loop sat inside an `ATTEMPT` block and the
+`PASS` in it returned past `CLEANUP`, so a scan error left the file open. Hoisting
+the loop into its own helper — which converting `fgets` required anyway, because
+neither `CATCH` nor `PASS` is legal in a loop inside an `ATTEMPT` — fixes it. That
+is the protocol's own rule catching a real leak the moment somebody had to obey it.
+
+### Still true, and still the reason one count is not a plan
+
+akbasic uses no allocator, no lists and no trees, drawing everything from fixed
+pools by design, and porting it did not change that. Of the 313 calls it now
+makes:
+
+| Area | Calls | |
+|---|---|---|
+| Strings | 149 | 47.6% |
+| Memory | 72 | 23.0% |
+| Formatted output | 43 | 13.7% |
+| Streams and files | 36 | 11.5% |
+| String → number | 12 | 3.8% |
+| Hashing | 1 | 0.3% |
+| **Collections** | **0** | **0%** |
+
+**Five sixths of the evidence is strings, memory and formatting.** The collections
+work — list, tree, hash map, string buffer, `src/collections.c` and the largest
+single body of code in this library — has **not one consumer call site**, and the
+single hashing call next to it is `aksl_strhash_djb2` feeding a hash table akbasic
+wrote for itself. **A consumer that does allocate would weight the
+`open`/`read`/`write` work far higher than this one does**, so this remains
+evidence and not a plan.
+
+**The number to distrust is not the 2.2%; it is the 0%.** A recount that moves
+92% to 2% on one consumer says the string, memory and format wrappers fit the
+consumer that asked for them. It says nothing at all about the half of the library
+that consumer never calls, and it cannot, however many times it is run. What would
+say something is a second consumer with different shape — one that allocates.
+
+`akbasic/src/symtab.c` is the sharpest instance. It is the hand-rolled fixed-capacity
+string-keyed hash table `aksl_hashmap_*` was generalised from, it survived the port
+untouched, and the reason turned out to be one field rather than a design
+disagreement — everything else about the two already lines up. #35 has it, and it
+is the first collections work with a consumer actually waiting for it.

scripts/consumer_calls.py

@@ -0,0 +1,245 @@
+#!/usr/bin/env python3
+"""
+Consumer adoption harness for libakstdlib.
+
+Answers one question about a consumer's source tree: how often does it call
+this library, and how often does it reach past this library to the libc
+function this library wraps?
+
+The ratio is the only external evidence there is about whether the surface that
+got built is the surface anyone wanted. A wrapper nobody calls is a wrapper that
+either does not fit or is not discoverable, and both are the library's problem.
+
+The number this reports is only worth something if it is reproducible, which is
+why this is a script and not a paragraph. TODO.md's first consumer figure was
+recorded without one, and recovering the method afterwards cost more than
+writing it down would have.
+
+WHAT COUNTS
+
+  * The corpus is every *.c and *.h directly under the given directory. It does
+    not recurse: a consumer's src/ is the thing being measured, not its vendored
+    dependencies, and those are usually a subdirectory.
+
+  * Comments and string/character literals are stripped before anything is
+    counted, so a function named in prose or inside a format string does not
+    score. This matters more than it sounds -- "strlen" appears in doc comments
+    throughout a codebase that has been thinking about strlen.
+
+  * A call site is IDENT immediately followed by '(', where IDENT is not
+    preceded by an identifier character. Declarations are not distinguished from
+    calls; a consumer that declares a function named for a libc entry point will
+    over-count by one per declaration, which is visible in --detail.
+
+  * A library call is any IDENT matching ^aksl_.
+
+  * A bypass is any IDENT naming a libc function this library wraps. That set is
+    read out of include/akstdlib.h rather than hardcoded, so it grows when the
+    library grows and a recount after a release measures the surface that
+    release actually shipped.
+
+  * libc functions this library does NOT wrap -- isdigit, exit, qsort -- score
+    on neither side. The question is how often a consumer bypasses an available
+    wrapper, not how much libc it uses. Adding a wrapper for something and
+    having it ignored is a finding; a consumer calling exit() is not.
+
+WHAT IT CANNOT TELL YOU
+
+  One consumer's ratio is evidence, not a plan. A consumer that draws
+  everything from fixed pools will never call the allocator no matter how good
+  the allocator is, and will weight the string wrappers accordingly. Weight the
+  result by what the consumer is, and get a second consumer before treating any
+  ranking as settled.
+
+Usage:
+    scripts/consumer_calls.py DIR [options]
+
+    DIR                 consumer source directory to measure, e.g.
+                        ../akbasic/src
+    --header PATH       akstdlib.h to read the wrapped-libc set from
+                        (default: include/akstdlib.h beside this script's repo)
+    --detail            list the per-function breakdown on both sides
+    --per-file          list per-file counts, worst bypass ratio first
+    --baseline A/B      compare against a previous count, e.g. --baseline 10/119
+    --json              emit the whole result as JSON instead of text
+"""
+
+import argparse
+import json
+import os
+import re
+import sys
+from collections import Counter
+
+# Wrapper families that are this library's own constructs rather than a libc
+# function under a new name. aksl_list_append has no libc counterpart, so
+# "append" must not become a name a consumer can be scored for bypassing.
+LIBRARY_ONLY_PREFIXES = ("hashmap", "list", "tree", "strbuf", "version",
+                         "strhash")
+
+# Library-only names whose first underscore-separated word is shared with a real
+# libc entry point, so a prefix rule cannot separate them. aksl_realpath wraps
+# realpath(3) and must score; aksl_realpath_alloc is this library's own.
+LIBRARY_ONLY_NAMES = frozenset(("freep", "realpath_alloc"))
+
+CALL = re.compile(r"(?<![A-Za-z0-9_])([A-Za-z_][A-Za-z0-9_]*)\s*\(")
+
+
+def wrapped_libc(header):
+    """The set of libc names this library wraps, read out of the header."""
+    with open(header, encoding="utf-8", errors="replace") as handle:
+        text = handle.read()
+    names = set()
+    for match in re.finditer(r"\baksl_([a-z0-9_]+)\s*\(", text):
+        name = match.group(1)
+        if name.split("_")[0] in LIBRARY_ONLY_PREFIXES:
+            continue
+        if name in LIBRARY_ONLY_NAMES:
+            continue
+        names.add(name)
+    return names
+
+
+def strip_c(src):
+    """Remove comments and string/char literals, preserving everything else."""
+    out = []
+    i, end = 0, len(src)
+    while i < end:
+        char = src[i]
+        if char == "/" and i + 1 < end and src[i + 1] == "/":
+            while i < end and src[i] != "\n":
+                i += 1
+        elif char == "/" and i + 1 < end and src[i + 1] == "*":
+            i += 2
+            while i + 1 < end and not (src[i] == "*" and src[i + 1] == "/"):
+                i += 1
+            i += 2
+        elif char in ('"', "'"):
+            quote = char
+            i += 1
+            while i < end and src[i] != quote:
+                if src[i] == "\\":
+                    i += 1
+                i += 1
+            i += 1
+            out.append(" ")
+        else:
+            out.append(char)
+            i += 1
+    return "".join(out)
+
+
+def measure(srcdir, libc):
+    """Count library and bypass call sites across one directory."""
+    library, bypass, per_file = Counter(), Counter(), {}
+    names = sorted(name for name in os.listdir(srcdir)
+                   if name.endswith((".c", ".h")))
+    for name in names:
+        with open(os.path.join(srcdir, name), encoding="utf-8",
+                  errors="replace") as handle:
+            text = strip_c(handle.read())
+        here_lib = here_raw = 0
+        for match in CALL.finditer(text):
+            ident = match.group(1)
+            if ident.startswith("aksl_"):
+                library[ident] += 1
+                here_lib += 1
+            elif ident in libc:
+                bypass[ident] += 1
+                here_raw += 1
+        if here_lib or here_raw:
+            per_file[name] = (here_lib, here_raw)
+    return library, bypass, per_file
+
+
+def rate(bypassed, total):
+    return 100.0 * bypassed / total if total else 0.0
+
+
+def main():
+    parser = argparse.ArgumentParser(add_help=True)
+    parser.add_argument("srcdir")
+    parser.add_argument("--header")
+    parser.add_argument("--detail", action="store_true")
+    parser.add_argument("--per-file", action="store_true")
+    parser.add_argument("--baseline")
+    parser.add_argument("--json", action="store_true")
+    args = parser.parse_args()
+
+    header = args.header or os.path.join(
+        os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
+        "include", "akstdlib.h")
+    if not os.path.isfile(header):
+        sys.stderr.write(f"error: no such header: {header}\n")
+        return 2
+    if not os.path.isdir(args.srcdir):
+        sys.stderr.write(f"error: no such directory: {args.srcdir}\n")
+        return 2
+
+    libc = wrapped_libc(header)
+    library, bypass, per_file = measure(args.srcdir, libc)
+    lib_total, raw_total = sum(library.values()), sum(bypass.values())
+    total = lib_total + raw_total
+
+    if args.json:
+        print(json.dumps({
+            "source": os.path.abspath(args.srcdir),
+            "header": os.path.abspath(header),
+            "wrapped_libc_names": len(libc),
+            "library_calls": lib_total,
+            "bypass_calls": raw_total,
+            "bypass_pct": round(rate(raw_total, total), 1),
+            "library_breakdown": dict(library.most_common()),
+            "bypass_breakdown": dict(bypass.most_common()),
+            "per_file": {k: {"library": v[0], "bypass": v[1]}
+                         for k, v in per_file.items()},
+        }, indent=2))
+        return 0
+
+    print(f"consumer   : {os.path.abspath(args.srcdir)}")
+    print(f"measured against: {os.path.abspath(header)} "
+          f"({len(libc)} wrapped libc names)")
+    print()
+    print(f"libakstdlib calls : {lib_total}")
+    print(f"bypassed to libc  : {raw_total}")
+    print(f"bypass rate       : {rate(raw_total, total):.1f}%  "
+          f"({raw_total}/{total})")
+
+    if args.baseline:
+        try:
+            was_lib, was_raw = (int(part) for part in args.baseline.split("/"))
+        except ValueError:
+            sys.stderr.write("error: --baseline wants LIBRARY/BYPASS, "
+                             "e.g. 10/119\n")
+            return 2
+        was_total = was_lib + was_raw
+        print()
+        print(f"baseline          : {was_lib} / {was_raw}  "
+              f"({rate(was_raw, was_total):.1f}% bypass)")
+        print(f"change            : {lib_total - was_lib:+d} library, "
+              f"{raw_total - was_raw:+d} bypass, "
+              f"{rate(raw_total, total) - rate(was_raw, was_total):+.1f} pt")
+        print()
+        print("A bypass rate is only comparable between two counts of the same")
+        print("tree. If the consumer grew between them, compare the rate and")
+        print("not the totals -- and say which tree each number came from.")
+
+    if args.detail:
+        print("\nbypassed to libc")
+        for name, count in bypass.most_common():
+            print(f"  {name:<22}{count}")
+        print("\ncalls into libakstdlib")
+        for name, count in library.most_common():
+            print(f"  {name:<22}{count}")
+
+    if args.per_file:
+        print("\nper file (library, bypass), worst bypass first")
+        order = sorted(per_file.items(), key=lambda kv: (-kv[1][1], kv[0]))
+        for name, (lib, raw) in order:
+            print(f"  {name:<32}{lib:>5}{raw:>6}")
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())