Merge branches/quickjs to trunk. This is the way.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@3621 ed5197a5-7fde-0310-b194-c3ffbd925b24

deps/quickjs/doc/quickjs.texi

@@ -20,34 +20,34 @@
 @chapter Introduction
 
 QuickJS is a small and embeddable Javascript engine. It supports the
-ES2019 specification
-@footnote{@url{https://www.ecma-international.org/ecma-262/10.0}}
-including modules, asynchronous generators and proxies.
+ES2020 specification
+@footnote{@url{https://tc39.es/ecma262/}}
+including modules, asynchronous generators, proxies and BigInt.
 
-It optionally supports mathematical extensions such as big integers
-(BigInt), big floating point numbers (BigFloat) and operator
-overloading.
+It supports mathematical extensions such as big decimal float float
+numbers (BigDecimal), big binary floating point numbers (BigFloat),
+and operator overloading.
 
 @section Main Features
 
 @itemize
 
-@item Small and easily embeddable: just a few C files, no external dependency, 180 KiB of x86 code for a simple ``hello world'' program.
+@item Small and easily embeddable: just a few C files, no external dependency, 210 KiB of x86 code for a simple ``hello world'' program.
 
 @item Fast interpreter with very low startup time: runs the 69000 tests of the ECMAScript Test Suite@footnote{@url{https://github.com/tc39/test262}} in about 95 seconds on a single core of a desktop PC. The complete life cycle of a runtime instance completes in less than 300 microseconds.
 
-@item Almost complete ES2019 support including modules, asynchronous
+@item Almost complete ES2020 support including modules, asynchronous
 generators and full Annex B support (legacy web compatibility). Many
-features from the upcoming ES2020 specification
+features from the upcoming ES2021 specification
 @footnote{@url{https://tc39.github.io/ecma262/}} are also supported.
 
-@item Passes nearly 100% of the ECMAScript Test Suite tests when selecting the ES2019 features.
+@item Passes nearly 100% of the ECMAScript Test Suite tests when selecting the ES2020 features.
 
-@item Can compile Javascript sources to executables with no external dependency.
+@item Compile Javascript sources to executables with no external dependency.
 
 @item Garbage collection using reference counting (to reduce memory usage and have deterministic behavior) with cycle removal.
 
-@item Mathematical extensions: BigInt, BigFloat, operator overloading, bigint mode, math mode.
+@item Mathematical extensions: BigDecimal, BigFloat, operator overloading, bigint mode, math mode.
 
 @item Command line interpreter with contextual colorization and completion implemented in Javascript.
 
@@ -87,28 +87,12 @@ Javascript files and/or expressions as arguments to execute them:
 
 generates a @code{hello} executable with no external dependency.
 
-@code{qjsbn} and @code{qjscbn} are the corresponding interpreter and
-compiler with the mathematical extensions:
-
-@example
-./qjsbn examples/pi.js 1000
-@end example
-
-displays 1000 digits of PI.
-
-@example
-./qjsbnc -o pi examples/pi.js
-./pi 1000
-@end example
-
-compiles and executes the PI program.
-
 @section Command line options
 
 @subsection @code{qjs} interpreter
 
 @verbatim
-usage: qjs [options] [files]
+usage: qjs [options] [file [args]]
 @end verbatim
 
 Options are:
@@ -127,16 +111,30 @@ Go to interactive mode (it is not the default when files are provided on the com
 
 @item -m
 @item --module
-Load as ES6 module (default=autodetect).
+Load as ES6 module (default=autodetect). A module is autodetected if
+the filename extension is @code{.mjs} or if the first keyword of the
+source is @code{import}.
 
 @item --script
 Load as ES6 script (default=autodetect).
 
+@item --bignum
+Enable the bignum extensions: BigDecimal object, BigFloat object and
+the @code{"use math"} directive.
+
+@item -I file
+@item --include file
+Include an additional file.
+
 @end table
 
 Advanced options are:
 
 @table @code
+@item --std
+Make the @code{std} and @code{os} modules available to the loaded
+script even if it is not a module.
+
 @item -d
 @item --dump
 Dump the memory usage stats.
@@ -169,6 +167,12 @@ Set the C name of the generated data.
 @item -m
 Compile as Javascript module (default=autodetect).
 
+@item -D module_name
+Compile a dynamically loaded module and its dependencies. This option
+is needed when your code uses the @code{import} keyword or the
+@code{os.Worker} constructor because the compiler cannot statically
+find the name of the dynamically loaded modules.
+
 @item -M module_name[,cname]
 Add initialization code for an external C module. See the
 @code{c_module} example.
@@ -181,14 +185,18 @@ Use link time optimization. The compilation is slower but the
 executable is smaller and faster. This option is automatically set
 when the @code{-fno-x} options are used.
 
-@item -fno-[eval|string-normalize|regexp|json|proxy|map|typedarray|promise]
+@item -fno-[eval|string-normalize|regexp|json|proxy|map|typedarray|promise|bigint]
 Disable selected language features to produce a smaller executable file.
 
+@item -fbignum
+Enable the bignum extensions: BigDecimal object, BigFloat object and
+the @code{"use math"} directive.
+
 @end table
 
 @section @code{qjscalc} application
 
-The @code{qjscalc} application is a superset of the @code{qjsbn}
+The @code{qjscalc} application is a superset of the @code{qjs}
 command line interpreter implementing a Javascript calculator with
 arbitrarily large integer and floating point numbers, fractions,
 complex numbers, polynomials and matrices. The source code is in
@@ -202,13 +210,8 @@ QuickJS archive.
 
 @section Test262 (ECMAScript Test Suite)
 
-A test262 runner is included in the QuickJS archive.
-
-For reference, the full test262 tests are provided in the archive
-@file{qjs-tests-yyyy-mm-dd.tar.xz}. You just need to untar it into the
-QuickJS source code directory.
-
-Alternatively, the test262 tests can be installed with:
+A test262 runner is included in the QuickJS archive. The test262 tests
+can be installed in the QuickJS source directory with:
 
 @example
 git clone https://github.com/tc39/test262.git test262
@@ -227,13 +230,12 @@ The tests can be run with
 make test2
 @end example
 
-The configuration files @code{test262.conf} (resp
-@code{test262bn.conf} for the bignum version, @code{test262o.conf} for
-the old ES5.1 tests@footnote{The old ES5.1 tests can be extracted with
-@code{git clone --single-branch --branch es5-tests
-https://github.com/tc39/test262.git test262o}})) contain the options
-to run the various tests. Tests can be excluded based on features or
-filename.
+The configuration files @code{test262.conf}
+(resp. @code{test262o.conf} for the old ES5.1 tests@footnote{The old
+ES5.1 tests can be extracted with @code{git clone --single-branch
+--branch es5-tests https://github.com/tc39/test262.git test262o}}))
+contain the options to run the various tests. Tests can be excluded
+based on features or filename.
 
 The file @code{test262_errors.txt} contains the current list of
 errors. The runner displays a message when a new error appears or when
@@ -263,25 +265,19 @@ about 100 seconds).
 
 @section Language support
 
-@subsection ES2019 support
+@subsection ES2020 support
 
-The ES2019 specification is almost fully supported including the Annex
+The ES2020 specification is almost fully supported including the Annex
 B (legacy web compatibility) and the Unicode related features.
 
 The following features are not supported yet:
 
 @itemize
 
-@item Realms (althougth the C API supports different runtimes and contexts)
-
 @item Tail calls@footnote{We believe the current specification of tails calls is too complicated and presents limited practical interests.}
 
 @end itemize
 
-@subsection JSON
-
-The JSON parser is currently more tolerant than the specification.
-
 @subsection ECMA402
 
 ECMA402 (Internationalization API) is not supported.
@@ -298,13 +294,12 @@ ECMA402 (Internationalization API) is not supported.
 
 @subsection Mathematical extensions
 
-The mathematical extensions are available in the @code{qjsbn} version and are fully
-backward compatible with standard Javascript. See @code{jsbignum.pdf}
-for more information.
+The mathematical extensions are fully backward compatible with
+standard Javascript. See @code{jsbignum.pdf} for more information.
 
 @itemize
 
-@item The @code{BigInt} (big integers) TC39 proposal is supported.
+@item @code{BigDecimal} support: arbitrary large floating point numbers in base 10.
 
 @item @code{BigFloat} support: arbitrary large floating point numbers in base 2.
 
@@ -364,56 +359,55 @@ Available exports:
 @item exit(n)
 Exit the process.
 
-@item evalScript(str)
-Evaluate the string @code{str} as a script (global eval).
+@item evalScript(str, options = undefined)
+Evaluate the string @code{str} as a script (global
+eval). @code{options} is an optional object containing the following
+optional properties:
+
+  @table @code
+  @item backtrace_barrier
+  Boolean (default = false). If true, error backtraces do not list the
+  stack frames below the evalScript.
+  @end table
 
 @item loadScript(filename)
 Evaluate the file @code{filename} as a script (global eval).
 
-@item Error(errno)
+@item loadFile(filename)
+Load the file @code{filename} and return it as a string assuming UTF-8
+encoding. Return @code{null} in case of I/O error.
 
-@code{std.Error} constructor. Error instances contain the field
-@code{errno} (error code) and @code{message} (result of
-@code{std.Error.strerror(errno)}).
+@item open(filename, flags, errorObj = undefined)
+Open a file (wrapper to the libc @code{fopen()}). Return the FILE
+object or @code{null} in case of I/O error. If @code{errorObj} is not
+undefined, set its @code{errno} property to the error code or to 0 if
+no error occured.
 
-The constructor contains the following fields:
+@item popen(command, flags, errorObj = undefined)
+Open a process by creating a pipe (wrapper to the libc
+@code{popen()}). Return the FILE
+object or @code{null} in case of I/O error. If @code{errorObj} is not
+undefined, set its @code{errno} property to the error code or to 0 if
+no error occured.
 
-  @table @code
-  @item EINVAL
-  @item EIO
-  @item EACCES
-  @item EEXIST
-  @item ENOSPC
-  @item ENOSYS
-  @item EBUSY
-  @item ENOENT
-  @item EPERM
-  @item EPIPE
-    Integer value of common errors (additional error codes may be defined).
-  @item strerror(errno)
-    Return a string that describes the error @code{errno}.
-  @end table
-
-@item open(filename, flags)
-Open a file (wrapper to the libc @code{fopen()}). Throws 
-@code{std.Error} in case of I/O error.
-
-@item popen(command, flags)
-Open a process by creating a pipe (wrapper to the libc @code{popen()}). Throws 
-@code{std.Error} in case of I/O error.
-
-@item fdopen(fd, flags)
+@item fdopen(fd, flags, errorObj = undefined)
 Open a file from a file handle (wrapper to the libc
-@code{fdopen()}). Throws @code{std.Error} in case of I/O error.
+@code{fdopen()}). Return the FILE
+object or @code{null} in case of I/O error. If @code{errorObj} is not
+undefined, set its @code{errno} property to the error code or to 0 if
+no error occured.
 
-@item tmpfile()
-Open a temporary file. Throws @code{std.Error} in case of I/O error.
+@item tmpfile(errorObj = undefined)
+Open a temporary file. Return the FILE
+object or @code{null} in case of I/O error. If @code{errorObj} is not
+undefined, set its @code{errno} property to the error code or to 0 if
+no error occured.
 
 @item puts(str)
 Equivalent to @code{std.out.puts(str)}.
 
 @item printf(fmt, ...args)
-Equivalent to @code{std.out.printf(fmt, ...args)}
+Equivalent to @code{std.out.printf(fmt, ...args)}.
 
 @item sprintf(fmt, ...args)
 Equivalent to the libc sprintf().
@@ -428,6 +422,27 @@ Wrappers to the libc file @code{stdin}, @code{stdout}, @code{stderr}.
 @item SEEK_END
 Constants for seek().
 
+@item Error
+
+Enumeration object containing the integer value of common errors
+(additional error codes may be defined):
+
+  @table @code
+  @item EINVAL
+  @item EIO
+  @item EACCES
+  @item EEXIST
+  @item ENOSPC
+  @item ENOSYS
+  @item EBUSY
+  @item ENOENT
+  @item EPERM
+  @item EPIPE
+  @end table
+
+@item strerror(errno)
+Return a string that describes the error @code{errno}.
+
 @item gc()
 Manually invoke the cycle removal algorithm. The cycle removal
 algorithm is automatically started when needed, so this function is
@@ -437,6 +452,16 @@ useful in case of specific memory constraints or for testing.
 Return the value of the environment variable @code{name} or
 @code{undefined} if it is not defined.
 
+@item setenv(name, value)
+Set the value of the environment variable @code{name} to the string
+@code{value}.
+
+@item unsetenv(name)
+Delete the environment variable @code{name}.
+
+@item getenviron()
+Return an object containing the environment variables as key-value pairs.
+
 @item urlGet(url, options = undefined)
 
 Download @code{url} using the @file{curl} command line
@@ -450,37 +475,66 @@ optional properties:
   to be UTF-8 encoded.
 
   @item full
+  
   Boolean (default = false). If true, return the an object contains
   the properties @code{response} (response content),
   @code{responseHeaders} (headers separated by CRLF), @code{status}
-  (status code). If @code{full} is false, only the response is
-  returned if the status is between 200 and 299. Otherwise an
-  @code{std.Error} exception is raised.
+  (status code). @code{response} is @code{null} is case of protocol or
+  network error. If @code{full} is false, only the response is
+  returned if the status is between 200 and 299. Otherwise @code{null}
+  is returned.
 
   @end table
 
+@item parseExtJSON(str)
+
+  Parse @code{str} using a superset of @code{JSON.parse}. The
+  following extensions are accepted:
+
+  @itemize
+  @item Single line and multiline comments
+  @item unquoted properties (ASCII-only Javascript identifiers)
+  @item trailing comma in array and object definitions
+  @item single quoted strings
+  @item @code{\f} and @code{\v} are accepted as space characters
+  @item leading plus in numbers
+  @item octal (@code{0o} prefix) and hexadecimal (@code{0x} prefix) numbers
+  @end itemize
 @end table
 
 FILE prototype:
 
 @table @code
 @item close()
-Close the file.
+Close the file. Return 0 if OK or @code{-errno} in case of I/O error.
 @item puts(str)
 Outputs the string with the UTF-8 encoding.
 @item printf(fmt, ...args)
-Formatted printf, same formats as the libc printf.
+Formatted printf.
+
+The same formats as the standard C library @code{printf} are
+supported. Integer format types (e.g. @code{%d}) truncate the Numbers
+or BigInts to 32 bits. Use the @code{l} modifier (e.g. @code{%ld}) to
+truncate to 64 bits.
+
 @item flush()
 Flush the buffered file.
 @item seek(offset, whence)
-Seek to a give file position (whence is @code{std.SEEK_*}). Throws a
-@code{std.Error} in case of I/O error.
+Seek to a give file position (whence is
+@code{std.SEEK_*}). @code{offset} can be a number or a bigint. Return
+0 if OK or @code{-errno} in case of I/O error.
 @item tell()
 Return the current file position.
+@item tello()
+Return the current file position as a bigint.
 @item eof()
 Return true if end of file.
 @item fileno()
 Return the associated OS handle.
+@item error()
+Return true if there was an error.
+@item clearerr()
+Clear the error indication.
 
 @item read(buffer, position, length)
 Read @code{length} bytes from the file to the ArrayBuffer @code{buffer} at byte
@@ -488,14 +542,19 @@ position @code{position} (wrapper to the libc @code{fread}).
 
 @item write(buffer, position, length)
 Write @code{length} bytes to the file from the ArrayBuffer @code{buffer} at byte
-position @code{position} (wrapper to the libc @code{fread}).
+position @code{position} (wrapper to the libc @code{fwrite}).
 
 @item getline()
 Return the next line from the file, assuming UTF-8 encoding, excluding
 the trailing line feed.
 
+@item readAsString(max_size = undefined)
+Read @code{max_size} bytes from the file and return them as a string
+assuming UTF-8 encoding. If @code{max_size} is not present, the file
+is read up its end.
+
 @item getByte()
-Return the next byte from the file.
+Return the next byte from the file. Return -1 if the end of file is reached.
 
 @item putByte(c)
 Write one byte to the file.
@@ -510,6 +569,7 @@ The @code{os} module provides Operating System specific functions:
 @item signals
 @item timers
 @item asynchronous I/O
+@item workers (threads)
 @end itemize
 
 The OS functions usually return 0 if OK or an OS specific negative
@@ -537,7 +597,9 @@ POSIX open flags.
 Close the file handle @code{fd}.
 
 @item seek(fd, offset, whence)
-Seek in the file. Use @code{std.SEEK_*} for @code{whence}.
+Seek in the file. Use @code{std.SEEK_*} for
+@code{whence}. @code{offset} is either a number or a bigint. If
+@code{offset} is a bigint, a bigint is returned too.
 
 @item read(fd, buffer, offset, length)
 Read @code{length} bytes from the file handle @code{fd} to the
@@ -559,10 +621,10 @@ Return the TTY size as @code{[width, height]} or @code{null} if not available.
 Set the TTY in raw mode.
 
 @item remove(filename)
-Remove a file. Return 0 if OK or < 0 if error.
+Remove a file. Return 0 if OK or @code{-errno}.
 
 @item rename(oldname, newname)
-Rename a file. Return 0 if OK or < 0 if error.
+Rename a file. Return 0 if OK or @code{-errno}.
 
 @item realpath(path)
 Return @code{[str, err]} where @code{str} is the canonicalized absolute
@@ -572,8 +634,11 @@ pathname of @code{path} and @code{err} the error code.
 Return @code{[str, err]} where @code{str} is the current working directory
 and @code{err} the error code.
 
+@item chdir(path)
+Change the current directory. Return 0 if OK or @code{-errno}.
+
 @item mkdir(path, mode = 0o777)
-Create a directory at @code{path}. Return the error code.
+Create a directory at @code{path}. Return 0 if OK or @code{-errno}.
 
 @item stat(path)
 @item lstat(path)
@@ -602,10 +667,10 @@ Constants to interpret the @code{mode} property returned by
 
 @item utimes(path, atime, mtime)
 Change the access and modification times of the file @code{path}. The
-times are specified in milliseconds since 1970.
+times are specified in milliseconds since 1970. Return 0 if OK or @code{-errno}.
 
 @item symlink(target, linkpath)
-Create a link at @code{linkpath} containing the string @code{target}.
+Create a link at @code{linkpath} containing the string @code{target}. Return 0 if OK or @code{-errno}.
 
 @item readlink(path)
 Return @code{[str, err]} where @code{str} is the link target and @code{err}
@@ -620,19 +685,19 @@ the error code.
 Add a read handler to the file handle @code{fd}. @code{func} is called
 each time there is data pending for @code{fd}. A single read handler
 per file handle is supported. Use @code{func = null} to remove the
-hander.
+handler.
 
 @item setWriteHandler(fd, func)
 Add a write handler to the file handle @code{fd}. @code{func} is
 called each time data can be written to @code{fd}. A single write
 handler per file handle is supported. Use @code{func = null} to remove
-the hander.
+the handler.
 
 @item signal(signal, func)
 Call the function @code{func} when the signal @code{signal}
 happens. Only a single handler per signal number is supported. Use
 @code{null} to set the default handler or @code{undefined} to ignore
-the signal.
+the signal. Signal handlers can only be defined in the main thread.
 
 @item SIGINT
 @item SIGABRT
@@ -652,7 +717,7 @@ object containing optional parameters:
   @table @code
   @item block
   Boolean (default = true). If true, wait until the process is
-  termined. In this case, @code{exec} return the exit code if positive
+  terminated. In this case, @code{exec} return the exit code if positive
   or the negated signal number if the process was interrupted by a
   signal. If false, do not block and return the process id of the child.
   
@@ -670,11 +735,23 @@ object containing optional parameters:
   @item stdout
   @item stderr
   If present, set the handle in the child for stdin, stdout or stderr.
- 
+
+  @item env
+  Object. If present, set the process environment from the object
+  key-value pairs. Otherwise use the same environment as the current
+  process.
+
+  @item uid
+  Integer. If present, the process uid with @code{setuid}.
+
+  @item gid 
+  Integer. If present, the process gid with @code{setgid}.
+
   @end table
 
 @item waitpid(pid, options)
-@code{waitpid} Unix system call. Return the array @code{[ret, status]}.
+@code{waitpid} Unix system call. Return the array @code{[ret,
+status]}. @code{ret} contains @code{-errno} in case of error.
 
 @item WNOHANG
 Constant for the @code{options} argument of @code{waitpid}.
@@ -703,6 +780,46 @@ Cancel a timer.
 Return a string representing the platform: @code{"linux"}, @code{"darwin"},
 @code{"win32"} or @code{"js"}.
 
+@item Worker(module_filename)
+Constructor to create a new thread (worker) with an API close to the
+@code{WebWorkers}. @code{module_filename} is a string specifying the
+module filename which is executed in the newly created thread. As for
+dynamically imported module, it is relative to the current script or
+module path. Threads normally don't share any data and communicate
+between each other with messages. Nested workers are not supported. An
+example is available in @file{tests/test_worker.js}.
+
+The worker class has the following static properties:
+
+  @table @code
+  @item parent
+  In the created worker, @code{Worker.parent} represents the parent
+  worker and is used to send or receive messages.
+  @end table
+
+The worker instances have the following properties:
+
+  @table @code
+  @item postMessage(msg)
+  
+  Send a message to the corresponding worker. @code{msg} is cloned in
+  the destination worker using an algorithm similar to the @code{HTML}
+  structured clone algorithm. @code{SharedArrayBuffer} are shared
+  between workers.
+
+  Current limitations: @code{Map} and @code{Set} are not supported
+  yet.
+
+  @item onmessage
+
+  Getter and setter. Set a function which is called each time a
+  message is received. The function is called with a single
+  argument. It is an object with a @code{data} property containing the
+  received message. The thread is not terminated if there is at least
+  one non @code{null} @code{onmessage} handler.
+
+  @end table
+
 @end table
 
 @section QuickJS C API
@@ -719,7 +836,7 @@ supported.
 
 @code{JSContext} represents a Javascript context (or Realm). Each
 JSContext has its own global objects and system objects. There can be
-several JSContexts per JSRuntime and they can share objects, similary
+several JSContexts per JSRuntime and they can share objects, similar
 to frames of the same origin sharing Javascript objects in a
 web browser.
 
@@ -727,7 +844,7 @@ web browser.
 
 @code{JSValue} represents a Javascript value which can be a primitive
 type or an object. Reference counting is used, so it is important to
-explicitely duplicate (@code{JS_DupValue()}, increment the reference
+explicitly duplicate (@code{JS_DupValue()}, increment the reference
 count) or free (@code{JS_FreeValue()}, decrement the reference count)
 JSValues.
 
@@ -747,9 +864,9 @@ general rule, C functions take constant @code{JSValue}s as parameters
 @subsection Exceptions
 
 Exceptions: most C functions can return a Javascript exception. It
-must be explicitely tested and handled by the C code. The specific
+must be explicitly tested and handled by the C code. The specific
 @code{JSValue} @code{JS_EXCEPTION} indicates that an exception
-occured. The actual exception object is stored in the
+occurred. The actual exception object is stored in the
 @code{JSContext} and can be retrieved with @code{JS_GetException()}.
 
 @subsection Script evaluation
@@ -934,16 +1051,16 @@ stack holds the Javascript parameters and local variables.
 
 @section RegExp
 
-A specific regular expression engine was developped. It is both small
+A specific regular expression engine was developed. It is both small
 and efficient and supports all the ES2020 features including the
 Unicode properties. As the Javascript compiler, it directly generates
 bytecode without a parse tree.
 
 Backtracking with an explicit stack is used so that there is no
-recursion on the system stack. Simple quantizers are specifically
+recursion on the system stack. Simple quantifiers are specifically
 optimized to avoid recursions.
 
-Infinite recursions coming from quantizers with empty terms are
+Infinite recursions coming from quantifiers with empty terms are
 avoided.
 
 The full regexp library weights about 15 KiB (x86 code), excluding the
@@ -951,9 +1068,9 @@ Unicode library.
 
 @section Unicode
 
-A specific Unicode library was developped so that there is no
+A specific Unicode library was developed so that there is no
 dependency on an external large Unicode library such as ICU. All the
-Unicode tables are compressed while keeping a reasonnable access
+Unicode tables are compressed while keeping a reasonable access
 speed.
 
 The library supports case conversion, Unicode normalization, Unicode
@@ -962,10 +1079,10 @@ binary properties.
 
 The full Unicode library weights about 45 KiB (x86 code).
 
-@section BigInt and BigFloat
+@section BigInt, BigFloat, BigDecimal
 
-BigInt and BigFloat are implemented with the @code{libbf}
-library@footnote{@url{https://bellard.org/libbf}}. It weights about 60
+BigInt, BigFloat and BigDecimal are implemented with the @code{libbf}
+library@footnote{@url{https://bellard.org/libbf}}. It weights about 90
 KiB (x86 code) and provides arbitrary precision IEEE 754 floating
 point operations and transcendental functions with exact rounding.