emoji plugin: generate char map from Unicode UTR51 data files

Refactor the functions and group listings to have fewer functions,
but have them take group names as parameters.
Pull group definitions in to a single associative array.

plugins/emoji/README.md

+# emoji plugin
+
+Support for conveniently working with Unicode emoji in Zsh.
+
+## Features
+
+This plugin provides support for working with Unicode emoji characters in `zsh` using human-readable identifiers. It provides global variables which map emoji names to the actual characters, country names to their flags, and some named groupings of emoji. It also provides associated functions for displaying them.
+
+#### Variables
+
+Variable          | Description
+----------------- | --------------------------------
+  $emoji          | Maps emoji names to characters
+  $emoji_flags    | Maps country names to flag characters (using region indicators)
+  $emoji_groups   | Named groups of emoji. Keys are group names; values are whitespace-separated lists of character names
+
+You may define new emoji groups at run time by modifying `$emoji_groups`. The special group name `all` is reserved for use by the plugin. You should not modify `$emoji` or `$emoji_flags`.
+
+#### Functions
+
+Function         | Description
+---------------- | -------------------------------
+  random_emoji   | Prints a random emoji character
+  display_emoji  | Displays emoji, along with their names
+
+## Usage and Examples
+
+To output a specific emoji, use:
+```
+$> echo $emoji[<name>]
+```
+E.g.:
+```
+$> echo $emoji[mouse_face]
+```
+
+To output a random emoji, use:
+```
+$> random_emoji
+```
+To output a random emoji from a particular group, use:
+```
+$> random_emoji <group>
+```
+E.g.:
+```
+$> random_emoji fruits
+$> random_emoji animals
+$> random_emoji vehicles
+$> random_emoji faces
+```
+
+The defined group names can be found with `echo ${(k)emoji_groups}`.
+
+To list all available emoji with their names, use:
+```
+$> display_emoji
+$> display_emoji fruits
+$> display_emoji animals
+$> display_emoji vehicles
+$> display_emoji faces
+```
+
+To use emoji in a prompt:
+```
+PROMPT="$emoji[penguin]  > ""
+PROMPT='$(random_emoji fruits)  > '
+surfer=$emoji[surfer]
+PROMPT="$surfer  > "
+```
+
+##  Technical Details
+
+The emoji names and codes are sourced from Unicode Technical Report \#51, which provides information on emoji support in Unicode. It can be found at http://www.unicode.org/reports/tr51/index.html.
+
+The group definitions are added by this OMZ plugin. They are not based on external definitions. (As far as I can tell. -apjanke)
+
+The values in the `$emoji*` maps are the emoji characters themselves, not escape sequences or other forms that require interpretation. They can be used in any context and do not require escape sequence support from commands like `echo` or `print`.
+
+The emoji in the main `$emoji` map are standalone character sequences which can all be output on their own, without worrying about combining characters. The values may actually be multi-code-point sequences, instead of a single code point, and may include combining characters in those sequences. But they're arranged so their effects do not extend beyond that sequence.
+
+The exception to this is the skin tone variation selectors. These are included in the main `$emoji` map because they can be displayed on their own, as well as used as combining characters. (If they follow a character that is not one of the emoji characters they combine with, they are displayed as color swatches.)
+
+
+##  Experimental Features
+
+This defines some additional variables and functions, but these are experimental and subject to change at any time. You shouldn't rely on them being available. They're mostly for the use of emoji plugin developers to help decide what to include in future revisions.
+
+Variables:
+
+Variable          | Description
+----------------- | --------------------------------
+  $emoji2         | Auxiliary and combining characters
+  $emoji_skintone | Skin tone modifiers (from Unicode 8.0)
+
+
+#### Skin Tone Variation Selection
+
+This includes experimental support for the skin tone Variation Selectors introduced with Unicode 8.0, which let you select different skin tones for emoji involving humans.
+
+NOTE: This really is experimental. The skin tone selectors are a relatively new feature and may not be supported by all systems. And the support in this plugin is a work in progress. It may not work in all places. In fact, I haven't gotten it to work anywhere yet. -apjanke
+
+The "variation selectors" are combining characters which change the appearance of the preceding character. A variation selector character can be output immediately following a human emoji to change its skin tone color. You can also output a variation selector on its own to display a color swatch of that skin tone.
+
+The `$emoji_skintone` associative array maps skin tone IDs to the variation selector characters. To use one, output it immediately following a smiley or other human emoji.
+
+```
+echo "$emoji[smiling_face_with_open_mouth]$emoji_skintone[4]"
+```
+
+Note that `$emoji_skintone` is an associative array, and its keys are the *names* of "Fitzpatrick Skin Type" groups, not linear indexes into a normal array. The names are `1_2`, `3`, `4`, `5`, and `6`. (Types 1 and 2 are combined into a single color.) See the [Diversity section in Unicode TR 51](http://www.unicode.org/reports/tr51/index.html#Diversity) for details.
+
+##  TODO
+
+These are things that could be enhanced in future revisions of the plugin.
+
+* Incorporate CLDR data for ordering and groupings
+* Short :bracket: style names (from gemoji)
+* Incorporate `gemoji` data
+* Country codes for flags
+* ZWJ combining function?
+
+####  Gemoji support
+
+The [gemoji project](https://github.com/github/gemoji) seems to be the de facto main source for short names and other emoji-related metadata that isn't included in the official Unicode reports. (I'm saying this just from looking at the google results for "emoji short names" and related searches. -apjanke)
+
+If this plugin is updated to provide short names, CLDR sorting data, and similar stuff, it should probably be changed to use the Gemoji project, and the `update_emoji.pl` script be rewritten in Ruby so it can use the Gemoji library directly instead of parsing its data files.
+
+This does *not* mean that it should use Gemoji at run time. None of the `zsh` plugin stuff should call Gemoji or Ruby code. Rather, the "build time" `update_emoji.pl` script should be rewritten to use Gemoji to generate a pure-native-`zsh` character definition file which would be checked in to the repo and can be called by OMZ users without having Gemoji installed.
+
+####  ZWJ combining function
+
+One of the newer features of Unicode emoji is the ability to use the "Zero-Width Joiner" character to compose multiple emoji characters in to a single "emoji ligature" glyph. For example, this is [how Apple supports "family" emoji with various genders and skin tones](http://www.unicode.org/reports/tr51/index.html#ZWJ_Sequences).
+
+These are a pain to write out (and probably worse to read), and it might be convenient to have a couple functions for concisely composing them, if wider support for them appears.

plugins/emoji/update_emoji.pl

+#!/usr/bin/perl -w
+#
+# update_emoji.pl
+#
+# This script generates the emoji.plugin.zsh emoji definitions from the Unicode
+# character data for the emoji characters.
+#
+# The data file can be found at http://unicode.org/Public/emoji/latest/emoji-data.txt
+# as referenced in Unicode TR51 (http://www.unicode.org/reports/tr51/index.html).
+#
+# This is known to work with the data file from version 1.0. It may not work with later
+# versions if the format changes. In particular, this reads line comments to get the
+# emoji character name and unicode version.
+#
+# Country names have punctuation and other non-letter characters removed from their name,
+# to avoid possible complications with having to escape the strings when using them as 
+# array subscripts. The definition file seems to use some combining characters like accents
+# that get stripped during this process.
+
+use strict;
+use warnings;
+use 5.010;
+use autodie;
+
+use Path::Class;
+use File::Copy;
+
+# Parse definitions out of the data file and convert
+sub process_emoji_data_file {
+	my ( $infile, $outfilename ) = @_;
+	my $file = file($infile);
+	my $outfile = file($outfilename);
+	my $outfilebase = $outfile->basename();
+	my $tempfilename = "$outfilename.tmp";
+	my $tempfile = file($tempfilename);
+	my $outfh = $tempfile->openw();
+	$outfh->print("
+# $outfilebase - Emoji character definitions for oh-my-zsh emoji plugin
+#
+# This file is auto-generated by update_emoji.pl. Do not edit it manually.
+#
+# This contains the definition for:
+#   \$emoji         - which maps character names to Unicode characters
+#   \$emoji_flags   - maps country names to Unicode flag characters using region indicators 
+
+# Main emoji
+typeset -gAH emoji
+# National flags
+typeset -gAH emoji_flags
+# Combining modifiers
+typeset -gAH emoji_mod
+
+");
+
+	my $fh = $file->openr();
+	my $line_num = 0;
+	while ( my $line = $fh->getline() ) {
+		$line_num++;
+		$_ = $line;
+		# Skip all-comment lines (from the header) and blank lines
+		# (But don't strip comments on normal lines; we need to parse those for
+		# the emoji names.)
+		next if /^\s*#/ or /^\s*$/;
+
+		if (/^(\S.*?\S)\s*;\s*(\w+)\s*;\s*(\w+)\s*;\s*(\w+)\s*;\s*(\w.*?)\s*#\s*V(\S+)\s\(.*?\)\s*(\w.*\S)\s*$/) {
+			my ($code, $style, $level, $modifier_status, $sources, $version, $keycap_name) 
+				= ($1, $2, $3, $4, $5, $6, $7);
+			#print "code=$code style=$style level=$level modifier_status=$modifier_status sources=$sources version=$version name=$keycap_name\n";
+			my @code_points = split /\s+/, $code;
+			my @sources = split /\s+/, $sources;
+
+			my $flag_country = "";
+			if ( $keycap_name =~ /^flag for (\S.*?)\s*$/) {
+				$flag_country = $1;
+			}
+
+			my $zsh_code = join '', map { "\\U$_" } @code_points;
+			# Convert keycap names to valid associative array names that do not require any
+			# quoting. Works fine for most stuff, but is clumsy for flags.
+			my $omz_name = lc($keycap_name);
+			$omz_name =~ s/[^A-Za-z0-9]/_/g;
+			my $zsh_flag_country = $flag_country;
+			$zsh_flag_country =~ s/[^\p{Letter}]/_/g;
+			if ($flag_country) {
+				$outfh->print("emoji_flags[$zsh_flag_country]=\$'$zsh_code'\n");
+			} else {
+				$outfh->print("emoji[$omz_name]=\$'$zsh_code'\n");				
+			}
+			# Modifiers are included in both the main set and their separate map,
+			# because they have a standalone representation as a color swatch.
+			if ( $modifier_status == "modifier" ) {
+				$outfh->print("emoji_mod[$omz_name]=\$'$zsh_code'\n");
+			}
+		} else {
+			die "Failed parsing line $line_num: '$_'";
+		}
+	}
+	$fh->close();
+	$outfh->print("\n");
+	$outfh->close();
+
+	move($tempfilename, $outfilename)
+		or die "Failed moving temp file to $outfilename: $!";
+}
+
+my $datafile = "emoji-data.txt";
+my $zsh_def_file = "emoji-char-definitions.zsh";
+process_emoji_data_file($datafile, $zsh_def_file);
+
+print "Updated definition file $zsh_def_file\n";
+
+
+