ClauseLibrary modules
Plan 11 step 39 (2026-10-07): a project-owned subset of OTP's lists and
maps modules, written in Erlang from OTP's documented behavior (not copied
from OTP sources) and compiled with the programs that use it.
Contents
| Module | Functions |
|---|---|
lists | append/1,2, filter/2, foldl/3, foldr/3, keyfind/3, map/2, member/2, nth/2, reverse/1,2, seq/2,3, sort/1 |
maps | find/2, fold/3, from_list/1, get/2, keys/1, put/3, to_list/1, values/1 |
file | open/2, read/2, write/2, read_line/1, position/2, close/1, read_file/1, write_file/2, delete/1, rename/2, list_dir/1, make_dir/1, del_dir/1 over the file driver (files) |
io | get_line/1,2, get_chars/2,3 (standard input server or an open file); format/1,2 and put_chars/1 are runtime builtins |
gen_tcp | listen/2, accept/1,2, connect/3,4, send/2, recv/2,3, shutdown/2, controlling_process/2, close/1 over socket ports (sockets) |
gen_udp | open/1,2, send/4, recv/2,3, controlling_process/2, close/1 |
inet | port/1, sockname/1, peername/1, setopts/2, close/1 |
clause_socket | Clause's own: the socket driver protocol the three modules above share |
os | cmd/1 over a port (subprocesses); type/0 and getenv/1 are runtime builtins |
Results and error reasons match OTP 29, including the error shapes of OTP's
Erlang implementations (lists:map(F, x) is {case_clause, x},
lists:nth(0, L) function_clause, lists:seq(1, 10, 0) badarg) and of
its BIFs (lists:member/2, lists:keyfind/3, lists:reverse/2, the maps
functions: badarg, {badmap, M}, {badkey, K}). lists:member/2 matches
with =:=, lists:keyfind/3 with ==. lists:sort/1 is a stable merge
sort. Stack traces name the library functions, not OTP's.
How programs get them
- When a batch (positional inputs or one project target) names a module with
a literal atom —
M:F(...)with literalM,fun M:F/A, orapply(M, F, Args)with literalM— that no input defines, and<library>/M.erlexists, the compiler parses and compiles that file into the batch, then repeats for the modules the added files name. A callM:F(...)of a catalog builtin (io:format/2,os:type/0) names no module. <library>islibrary/stdlibof the build tree, found relative toclaulike the runtime archive.- A module of the batch with the same name replaces the library module.
- Library modules are ordinary batch modules: they link into executables and, for object or IR output, produce their own artifacts.
- A module reached only through runtime names (
M:F(...)withMa variable) is not added: such a call raisesundefunless something else names the module. - Library functions are Erlang code, so they will yield like other code once the scheduler exists.