SPDX-FileCopyrightText: 2024 Lady <https://www.ladys.computer/about/#lady>
SPDX-License-Identifier: CC0-1.0
-->
-# ⛩️📰 书社
+# ⛩📰 书社
<b>A make·file for X·M·L.</b>
-<dfn>⛩️📰 书社</dfn> aims to make it easy to generate websites with
+<dfn>⛩📰 书社</dfn> aims to make it easy to generate websites with
X·S·L·T and G·N·U Make.
It is consequently only a good choice for people who like X·S·L·T and
G·N·U Make and wish it were easier to make websites with them.
installed on your computer†.
† Assuming an operating system with a fairly featureful, and
- Posix‐compliant, development setup (e·g, macOS).
+ Posix‐compliant, development setup (e·g, Macintosh ≥ version 10.8).
In fact, on Linux you will probably need to install a few programs:
`libxml2-utils`, `xsltproc`, `sharutils`, and `pax`.
The name <i lang="cmn-Hans">书社</i> was chosen to play on this pun, as
it is intended as a publishing program for webshrines.
-In Ascii environments, ⛩️📰 书社 should be written `Shushe`, following
+In Ascii environments, ⛩📰 书社 should be written `Shushe`, following
the pinyin transliteration.
## Prerequisites
-In most cases, ⛩️📰 书社 aims to require only functionality which is
- present in all Posix‐compliant operating systems.
+In most cases, ⛩📰 书社 aims to require only functionality which is
+ present in all Posix‐compliant (`POSIX.1-2001`) operating systems.
There are a few exceptions.
Details on particular programs are given below; if a program is not
listed, it is assumed that any Posix‐compliant implementation will
work.
-### `date`
-
-This is a Posix utility, but ⛩️📰 书社 currently depends on
- unspecified behaviour.
-When the G·N·U version of `stat` is being used, then the G·N·U version
- of `date` is also expected.
+### `diff`
+
+This is a Posix utility, but ⛩📰 书社 depends on functionality
+ introduced after `POSIX.1-2001` (the `-u` option, introduced in
+ `POSIX.1-2008`).
+Macintosh systems somewhat interestingly implement this option
+ correctly in legacy mode (`COMMAND_MODE=legacy`) but incorrectly by
+ default (despite claiming `POSIX.1-2008` conformance for this
+ utility).
+[Note this erroneous comment claiming nanosecond & timezone are
+ extensions rather than standardized.][rdar-92753335]
+Despite this, the default Macintosh implementation will still work with
+ ⛩📰 书社, with the caveat that the timestamp will only include a
+ fractional component when a Posix⹀compliant (e·g, Macintosh legacy or
+ G·N·U) implementation is used.
### `file`
-This is a Posix utility, but ⛩️📰 书社 currently depends on
- unspecified behaviour.
+This is a Posix utility, but it was considered optional in
+ `POSIX.1-2001` (altho it was made mandatory in `POSIX.1-2008`) and
+ ⛩📰 书社 currently depends on unspecified behaviour.
It requires support for the following additional options :—
- **`-C`**, when supplied with `-m`, must be useable to compile a
### `make`
-This is a Posix utility, but ⛩️📰 书社 currently depends on
- unspecified behaviour.
-⛩️📰 书社 requires specifically the G·N·U version of `make`, and
+This is a Posix utility, but it is considered an optional Software
+ Development utility and ⛩📰 书社 currently depends on unspecified
+ behaviour.
+⛩📰 书社 requires specifically the G·N·U version of `make`, and
depends on functionality present in version 3.81 or later.
It is not expected to work in previous versions, or with other
implementations of Make.
### `pax`
-This is a Posix utility, but not included in the Linux Standard Base or
- installed by default in many distributions.
-Only `ustar` format support is required.
-
-### `stat`
-
-This is not a Posix utility, and nor is it particularly portable.
-To get around incompatibilities, ⛩️📰 书社 attempts to recognize G·N·U
- `stat` by searching for the string `GNU` when invoked with the
- `--version` option, and falls back to B·S·D behaviour otherwise.
+This is a Posix utility, but it is not included in the Linux Standard
+ Base or installed by default in many distributions.
+⛩📰 书社 only requires support for the `ustar` format.
### `uudecode` and `uuencode`
-These are Posix utilities, but not included in the Linux Standard Base
- or installed by default in many distributions.
+These are Posix utilities, but they were considered optional in
+ `POSIX.1-2001` (altho they are made mandatory in `POSIX.1-2008`) and
+ they are not included in the Linux Standard Base or installed by
+ default in many distributions.
The G·N·U [Sharutils](https://www.gnu.org/software/sharutils/) package
- can be installed to access them.
+ provides one implementation.
### `xmlcatalog` and `xmllint`
These are not a Posix utilities.
-They is a part of `libxml2`, but may need to be installed separately
- (e·g by the name `libxml2-utils`).
+They are a part of `libxml2`, but may need to be installed separately
+ on some platforms (e·g by the name `libxml2-utils`).
### `xsltproc`
This is not a Posix utility.
-It is a part of `libxslt`, but may need to be installed separately.
+It is a part of `libxslt`, but may need to be installed separately on
+ some platforms.
## Basic Usage
the result to `public/`.
Compilation involves the following steps :—
-1. ⛩️📰 书社 compiles all of the magic files in `magic/` into a single
+1. ⛩📰 书社 compiles all of the magic files in `magic/` into a single
file, `build/magic.mgc`.
-2. ⛩️📰 书社 processes all of the parsers in `parsers/` and determines
+2. ⛩📰 书社 processes all of the parsers in `parsers/` and determines
the list of supported plaintext types.
-3. ⛩️📰 书社 identifies all of the source files and includes and uses
+3. ⛩📰 书社 identifies all of the source files and includes and uses
`build/magic.mgc` to classify them by media type.
-4. ⛩️📰 书社 parses all plaintext and X·M·L source files and includes
+4. ⛩📰 书社 parses all plaintext and X·M·L source files and includes
and then builds a dependency tree between them.
-5. ⛩️📰 书社 uses the dependency tree to establish prerequisites for
+5. ⛩📰 书社 uses the dependency tree to establish prerequisites for
each output file.
-6. ⛩️📰 书社 compiles each output file to `build/result`.
+6. ⛩📰 书社 compiles each output file to `build/result`.
-7. ⛩️📰 书社 copies most output files from `build/result` to
+7. ⛩📰 书社 copies most output files from `build/result` to
`build/public`, but it does some additional processing instead on
those which indicate a non‐X·M·L desired final output form.
-8. ⛩️📰 书社 copies the final resulting files to `public`.
+8. ⛩📰 书社 copies the final resulting files to `public`.
You can use `make list` to list each identified source file or include
alongside its computed type and dependencies.
## Name·spaces
-The ⛩️📰 书社 name·space is `urn:fdc:ladys.computer:20231231:Shu1She4`.
+The ⛩📰 书社 name·space is `urn:fdc:ladys.computer:20231231:Shu1She4`.
This document uses a few name·space prefixes, with the following
meanings :—
## Setup and Configuration
-⛩️📰 书社 depends on the following programs to run.
+⛩📰 书社 depends on the following programs to run.
In every case, you may supply your own implementation by overriding the
corresponding (allcaps) variable (e·g, set `MKDIR` to supply your own
`mkdir` implementation).
- `awk`
- `cat`
+- `cd`
- `cksum`
- `cp`
- `date`
-- `echo`
+- `diff`
- `file`
- `find`
- `git` (optional; set `GIT=` to disable)
- `grep`
- `ln`
-- `ls`
- `mkdir`
- `mv`
- `od`
- `rm`
- `sed`
- `sleep`
-- `stat` (BSD *or* GNU)
- `test`
- `touch`
- `tr`
- `xsltproc` (provided by `libxslt`)
The following additional variables can be used to control the behaviour
- of ⛩️📰 书社 :—
+ of ⛩📰 书社 :—
- **`SRCDIR`:**
The location of the source files (default: `sources`).
Multiple include directories can be provided, so long as the same
file subpath doesn’t exist in more than one of them.
+- **`DATADIR`:**
+ If set to the location of a directory, ⛩📰 书社 will run a two‐stage build.
+ In the first stage, only files in `SRCDIR` which match `FINDDATARULES` (see below) will be built, with files in `DATADIR` serving as includes.
+ In the second stage, the remaining files in `SRCDIR` will be built, with the files built during the first stage, in addition to any files in `INCLUDEDIR`, serving as includes.
+ Files built during the first stage are copied into `DESTDIR` alongside those from the second stage when installing.
+
+ This functionality is intended for sites where the bulk of the site can be built from a few data files which are expensive to create.
+
- **`BUILDDIR`:**
The location of the (temporary) build directory (default: `build`).
`make clean` will delete this, and it is recommended that it not be
- used for programs aside from ⛩️📰 书社.
+ used for programs aside from ⛩📰 书社.
- **`DESTDIR`:**
The location of directory to output files to (default: `public`).
ensure stale content is removed.
- **`THISDIR`:**
- The location of the ⛩️📰 书社 `GNUmakefile`.
+ The location of the ⛩📰 书社 `GNUmakefile`.
This should be set automatically when calling Make and shouldn’t ever
need to be set manually.
- This variable is used to find the ⛩️📰 书社 `lib/` folder, which is
+ This variable is used to find the ⛩📰 书社 `lib/` folder, which is
expected to be in the same location.
- **`MAGIC`:**
those which end with a cloparen, and those which contain a hash,
buck, percent, asterisk, colon, semi, eroteme, bracket, backslash,
or pipe.
+ It is important that these rules not produce any output, as anything
+ printed to `stdout` will be considered a result of the find.
- **`EXTRAFINDRULES`:**
The value of this variable is appended to `FINDRULES` by default, to
default, to enable additional rules without overriding the existing
ones.
+- **`DATAEXT`:**
+ A list of file extensions which signify “data” files during a two‐stage build using `DATADIR`.
+
+- **`FINDDATARULES`:**
+ Rules to use with `find` when searching for data files.
+ By default, these rules are derived from `DATAEXT`.
+
+- **`EXTRAFINDDATARULES`:**
+ The value of this variable is appended to `FINDDATARULES` by
+ default, to enable additional rules without overriding the existing
+ ones.
+
- **`PARSERS`:**
A white·space‐separated list of parsers to use (default:
`$(THISDIR)/parsers/*.xslt`).
The value of this variable is appended to `PARSERS` by default, to
enable additional parsers without overriding the existing ones.
+- **`PARSERLIBS`:**
+ A white·space‐separated list of parser dependencies (default:
+ `$(THISDIR)/lib/split.xslt`).
+
+- **`EXTRAPARSERLIBS`:**
+ The value of this variable is appended to `PARSERLIBS` by default, to
+ enable additional parser dependencies without overriding the
+ existing ones.
+
- **`TRANSFORMS`:**
A white·space‐separated list of transforms to use (default:
`$(THISDIR)/transforms/*.xslt`).
The value of this variable is appended to `TRANSFORMS` by default, to
enable additional transforms without overriding the existing ones.
+- **`TRANSFORMLIBS`:**
+ A white·space‐separated list of transform dependencies (default:
+ `$(THISDIR)/lib/serialize.xslt`).
+
+- **`EXTRATRANSFORMLIBS`:**
+ The value of this variable is appended to `TRANSFORMLIBS` by default,
+ to enable additional transform dependencies without overriding the
+ existing ones.
+
- **`XMLTYPES`:**
- A white·space‐separated list of media types to consider X·M·L
- (default: `application/xml text/xml`).
+ A white·space‐separated list of media types or media type suffixes to
+ consider X·M·L (default: `application/xml text/xml +xml`).
+
+- **`FINALIZE`:**
+ A program to run on (unspecial) X·M·L files after they are
+ transformed (default: `xmllint --nonet --nsclean`).
+ This variable can be used for postprocessing.
- **`THISREV`:**
- The current version of ⛩️📰 书社 (default: derived from the current
+ The current version of ⛩📰 书社 (default: derived from the current
git tag/branch/commit).
- **`SRCREV`:**
The current version of the source files (default: derived from the
current git tag/branch/commit).
+- **`QUIET`:**
+ If this variable has a value, informative messages will not be
+ printed (default: empty).
+ Informative messages print to stderr, not stdout, so disabling them
+ usually shouldn’t be necessary.
+ This does not (cannot) disable messages from Make itself, for which
+ the `-s`, `--silent` ∕ `--quiet` Make option is more likely to be
+ useful.
+
- **`VERBOSE`:**
If this variable has a value, every recipe instruction will be
printed when it runs (default: empty).
contain Ascii white·space, colons (`:`), semis (`;`), pipes (`|`),
bucks (`$`), percents (`%`), hashes (`#`), asterisks (`*`), brackets
(`[` or `]`), erotemes (`?`), backslashes (`\`), or control
- characters, must not begin with a hyphen‐minus (`-`), must not end
- with a cloparen (`)`), and must not contain quoted braces (`"{` or
- `}"`).**
+ characters, must not begin with a hyphen‐minus (`-`), and must not end
+ with a cloparen (`)`).**
The former characters have the potential to conflict with make syntax,
- a leading hyphen‐minus is confusable for a command‐line argument, a
+ a leading hyphen‐minus is confusable for a commandline argument, and a
trailing cloparen [activates a bug in G·N·U Make
- 3.81](https://stackoverflow.com/questions/17148468/capturing-filenames-including-parentheses-with-gnu-makes-wildcard-function#comment24825307_17148894),
- and quoted braces are used internally by the program.
+ 3.81](https://stackoverflow.com/questions/17148468/capturing-filenames-including-parentheses-with-gnu-makes-wildcard-function#comment24825307_17148894).
## Parsers
Parsers are used to convert plaintext files into X·M·L trees, as well
as convert plaintext formats which are already included inline in
existing source X·M·L documents.
-⛩️📰 书社 comes with some parsers; namely :—
+⛩📰 书社 comes with some parsers; namely :—
- **`parsers/plain.xslt`:**
Wraps `text/plain` contents in a `<html:pre>` element.
Converts `text/tab-separated-values` contents into an `<html:table>`
element.
-New ⛩️📰 书社 parsers which target plaintext formats should have an
+New ⛩📰 书社 parsers which target plaintext formats should have an
`<xslt:template>` element with no `@name` or `@mode` and whose
`@match` attribute…
</transform>
```
-⛩️📰 书社 will scan the provided parsers for this pattern to determine
+⛩📰 书社 will scan the provided parsers for this pattern to determine
the set of allowed plaintext file types.
Multiple such `<xslt:template>` elements may be provided in a single
parser, for example if the parser supports multiple media types.
### Attributes added during parsing
-⛩️📰 书社 will add a few attributes to the output of the parsing step,
- namely :—
+⛩📰 书社 will add a few attributes to elements which result from
+ parsing plaintext `<html:script>` elements.
+These include :—
-- A `@书社:cksum` attribute on toplevel result elements, giving the
- `cksum` checksum of the corresponding source file.
+- A `@书社:parsed-by` attribute, giving a space‐separated list of
+ parsers which parsed the node.
+ (Generally, this will be a list of one, but it is possible for the
+ result of a parse to be another plaintext node, which may be parsed
+ by a different parser.)
-- For the elements which result from parsing plaintext `<html:script>`
- elements :—
+- A `@书社:media-type` attribute, giving the identified media type of
+ the plaintext node.
- - A `@书社:parsed-by` attribute, giving a space‐separated list of
- parsers which parsed the node.
- (Generally, this will be a list of one, but it is possible for the
- result of a parse to be another plaintext node, which may be
- parsed by a different parser.)
+## Output Redirection
- - A `@书社:media-type` attribute, giving the identified media type of
- the plaintext node.
+By default, ⛩📰 书社 installs files to the same location in `DESTDIR`
+ as they were placed in their `SRCDIR`.
+This behaviour can be customized by setting the `@书社:destination`
+ attribute on the root element, whose value can give a different path.
+This attribute is read after parsing, but before transformation (where
+ it is silently dropped).
## Embedding
Embedding takes place after parsing but before transformation, so
parsers are able to generate their own embeds.
-⛩️📰 书社 is able to detect the transitive embed dependencies of files
+⛩📰 书社 is able to detect the transitive embed dependencies of files
and update them accordingly; it will signal an error if the
dependencies are recursive.
-## Output Redirection
+### Attributes added during expansion
-By default, ⛩️📰 书社 installs files to the same location in `DESTDIR`
- as they were placed in their `SRCDIR`.
-This behaviour can be customized by setting the `@书社:destination`
- attribute on the root element, whose value can give a different path.
-This attribute is read after parsing, but before transformation (where
- it is silently dropped).
+⛩📰 书社 will add a few attributes to toplevel result elements, both
+ in the main document and any embedded documents, during the expansion
+ phase prior to the main transformation.
+These include :—
+
+- A `@书社:cksum` attribute giving the `cksum` checksum of the
+ corresponding source file.
+
+- A `@书社:mtime` attribute giving the last modified time of the
+ corresponding source file.
+
+- A `@书社:identifier` attribute giving the ⛩📰 书社 identifier
+ (i·e, starting with `about:shushe?`) of the corresponding source
+ file.
+
+- For elements in the `html` namespace, an `itemscope` attribute and an
+ `itemtype` attribute with a value of
+ `urn:fdc:ladys.computer:20231231:Shu1She4:document` (for the main
+ document) or `urn:fdc:ladys.computer:20231231:Shu1She4:embed` (for
+ embedded documents).
+ These attributes are used to scope any nested `<html:meta>` elements
+ with `@itemprop` attributes to their containing documents.
## Transforms
Transforms are used to convert X·M·L files into their final output,
after all necessary parsing and embedding has taken place.
-⛩️📰 书社 comes with some transforms; namely :—
+⛩📰 书社 comes with some transforms; namely :—
- **`transforms/asset.xslt`:**
Converts `<html:object>` elements which correspond to recognized
media types into the appropriate H·T·M·L elements, and deletes
`<html:style>` elements from the body of the document and moves
them to the head.
+ This conversion happens during the finalization phase, after the main
+ transformation.
- **`transforms/metadata.xslt`:**
Provides basic `<html:head>` metadata.
- **`urn:fdc:ladys.computer:20231231:Shu1She4:title`:**
Provides the title of the page.
- ⛩️📰 书社 automatically encapsulates H·T·M·L embeds so that their
+ ⛩📰 书社 automatically encapsulates H·T·M·L embeds so that their
metadata does not propogate up to the embedding document.
To undo this behaviour, remove the `@itemscope` and `@itemtype`
attributes from the embed during the transformation phase.
- **`transforms/serialization.xslt`:**
Replaces `<书社:serialize-xml>` elements with the (escaped)
serialized X·M·L of their contents.
- This replacement happens during the application phase, after most
+ This replacement happens during the finalization phase, after most
other transformations have taken place.
If a `@with-namespaces` attribute is provided, any name·space nodes
name·space.
Multiple prefixes may be provided, separated by white·space.
- When it comes to name·spaces used internally by ⛩️📰 书社, the
- prefix used by ⛩️📰 书社 may be declared _in addition to_ the
+ When it comes to name·spaces used internally by ⛩📰 书社, the
+ prefix used by ⛩📰 书社 may be declared _in addition to_ the
prefix(es) used in the source document(s).
It is not possible to selectively only declare one prefix for a
name·space to the exclusion of others.
- **`BUILDTIME`:**
The current time.
-- **`CKSUM`:**
- The checksum of the source file (⅌ `cksum`).
-
- **`IDENTIFIER`:**
- The ⛩️📰 书社 identifier of the source file (a u·r·i beginning with
+ The ⛩📰 书社 identifier of the source file (a u·r·i beginning with
`about:shushe`).
- **`SRCREV`:**
The value of the `SRCREV` variable (if present).
-- **`SRCTIME`:**
- The time at which the source file was last modified.
-
- **`THISREV`:**
The value of the `THISREV` variable (if present).
-The following params are only available in transforms :—
-
-- **`CATALOG`:**
- The path of the catalog file (within `BUILDDIR`).
-
-- **`PATH`:**
- The path of the output file (within `DESTDIR`).
-
## Output Wrapping
-⛩️📰 书社 will wrap the final output of the transforms in appropriate
- `<html:html>` and `<html:body>` elements, so it is not necessary for
- transforms to do this explicitly.
-After performing the initial transform, ⛩️📰 书社 will match the root
- node of the result in the following modes to fill in areas of the
+Provided at least one toplevel result element belongs to the H·T·M·L
+ namespace, ⛩📰 书社 will wrap the final output of the transforms in
+ appropriate `<html:html>` and `<html:body>` elements, so it is not
+ necessary for transforms to do this explicitly.
+If a toplevel result element _is_ a `<html:html>` and `<html:body>`
+ element, it will be merged with the one that ⛩📰 书社 creates.
+Consequently, wrapping the result in a `<html:body>` element can be
+ used to enable wrapping for non‐H·T·M·L content, when desired.
+
+As a part of this process, after performing the initial transform
+ ⛩📰 书社 will match in the following modes to fill in areas of the
wrapper :—
- **`书社:header`:**
The result of matching in this mode is inserted into the
`<html:head>` of the output.
-In addition to being called with the transform result, each of these
- modes will additionally be called with a `<xslt:include>` element
- corresponding to each transform.
-If a transform has a `<书社:id>` top‐level element whose value is an
- i·r·i, its `<xslt:include>` element will have a corresponding
- `@书社:id` attribute.
-This mechanism can be used to allow transforms to insert content
- without matching any elements in the result; for example, the
- following transform adds a link to a stylesheet to the `<html:head>`
- of every page :—
+The document being matched will contain the full transform result
+ prior to wrapping as well as an `<书社:id>` element for each
+ transform.
+The latter elements can be matched to enable transforms to provide
+ content _without_ matching any elements in the result; for example,
+ the following transform adds a link to a stylesheet to the
+ `<html:head>` of every page :—
```xml
<?xml version="1.0"?>
version="1.0"
>
<书社:id>example:add-stylesheet-links.xslt</书社:id>
- <template match="xslt:include[@书社:id='example:add-stylesheet-links.xslt']" mode="书社:metadata">
+ <template match="书社:id[string(.)='example:add-stylesheet-links.xslt']" mode="书社:metadata">
<html:link rel="stylesheet" type="text/css" href="/style.css"/>
</template>
</transform>
the result tree.
It will not be performed on outputs whose root elements are
`<书社:archive>`, `<书社:base64-binary>`, or `<书社:raw-text>`
- (described below).
+ (described below), or on result trees which do not contain a toplevel
+ element in the H·T·M·L namespace.
## Applying Attributes
In both cases, attributes from various sources are combined with
white·space between them.
-Attribute application takes place after all ordinary transforms have
- completed.
+Attribute application takes place after each stage of the
+ transformation, including after the initial embedding phase.
Both elements ignore attributes in the `xml:` name·space, except for
`@xml:lang`, which ignores all but the first definition (including
There are a few special elements in the `书社:` name·space which, if
they appear as the toplevel element in a transformation result, cause
- ⛩️📰 书社 to produce something other than an X·M·L file.
+ ⛩📰 书社 to produce something other than an X·M·L file.
They are :—
- **`<书社:archive>`:**
Other child elements will be ignored.
If the `<书社:archive>` element is given an `@书社:expanded`
- attribute, rather than producing a tarball ⛩️📰 书社 will output
+ attribute, rather than producing a tarball ⛩📰 书社 will output
the directory which expanding the tarball would produce.
This mechanism can be used to generate multiple files from a single
source, provided all of the files are contained with·in the same
A plaintext (U·T·F‐8) file will be produced from the text nodes in
the transformation result.
-## Pagination
-
-It is possible to have a single source file produce multiple output
- files via `<书社:page>` elements, whose `@name` gives the name of the
- page.
-If a parsed document has a `@书社:destination` which contains `%s`,
- the `%s` will be replaced with the `@name` for each `<书社:page>` (and
- removed for the main output).
-Otherwise, the `@name` is inserted before the first period of the
- filename (or at the end of the filename for those with no period).
-If `<书社:page>`s do not have a `@name`, they are numbered
- sequentially.
-The destination of pages must be in the same directory as their parent.
-
-Pagination essentially forms a limited convenience for the more
- sophisticated technique of creating an archive with ⛩️📰 书社 and
- then unarchiving it.
-Pages are, from Make’s point of view, untracked side·effects of
- installing the main output, meaning they cannot be targeted directly
- and will not appear in `make list` or `make listout`.
-They are intended solely for the like of indices and feeds, for which
- convenience and necessity outweigh their flaws.
-
## License
This repository conforms to [REUSE][].
[REUSE]: <https://reuse.software/spec/>
[draft-phillips-record-jar-01]: <https://datatracker.ietf.org/doc/html/draft-phillips-record-jar-01>
+[rdar-92753335]: <https://github.com/apple-oss-distributions/patch_cmds/blob/5084833f90df1b0e0924ea56f94c0199b3b8bbc6/diff/diffreg.c#L1800-L1808>
Lady’s Gitweb / Shushe / blobdiff