wordforms

#!/bin/sh

print_help_and_exit () {
	printf "Usage: wordforms [-s | -p] DICTIONARY.aff DICTIONARY.dic STEM
       wordforms -g DICTIONARY.aff DICTIONARY.dic OUTPUT_FILE
Generate all variations of a word stem STEM in the dictionary file DICTIONARY.dic by
affixing all prefixes and suffixes listed as flags of the stem, based on rules stored
in DICTIONARY.aff, and print the results. If -g is given, generate every variation of
every stem in the dictionary file DICTIONARY.dic by affixing all relevant flags, and
write the results to file OUTPUT_FILE. Note that typically this will generate tens of
thousands of words.

  -s  print only the stem, and any suffixed forms of the stem
  -p  print only the stem, and any prefixed forms of the stem
  -g  generate all words in the entire dictionary and save them to a file
"
	exit 1
}

generate () {
	number_of_entries=$(( $( cat "$2" | wc -l ) - 1 ))
	awk -v number_of_entries="$number_of_entries" -v fx="$fx" '
	BEGIN {
		delete referenced_affix_names
		flag_type = "unicode"
		complex_prefixes = ""
		percent_complete = 0
		entry_step_per_percent = number_of_entries / 100
		next_update = entry_step_per_percent
	}
	
	function debug(text) {
		#print text > "/dev/tty"
		return
	}
	
	function print_to_terminal(text) {
		printf text > "/dev/tty"
	}
	
	function separate_flags(flags) {
		# temp array, grab its contents as soon as you run
		# this function (cant return arrays with awk).
		# array has numerical indices and char / string / number data
		delete separated_flags_array
		
		if (flag_type == "num") split(flags, separated_flags_array, ",");
		else if (flag_type == "long") {
			for (i=0; i*2<length(flags); i++) {
				separated_flags_array[i] = substr(flags, i*2, 2)
			}
		}
		else split(flags, separated_flags_array, "");
	}
	
	function affix_word(word, input_flags, location, affix_level) {
		debug("\n\nSTART AFFIX_WORD:\t" word "\t" input_flags "\t" location "\t" affix_level)
		delete to_be_processed[word "/" input_flags "/" location "/" affix_level]
		return_value = 0
		# separate the flags ("separated_flags_array" holds the data)
		separate_flags(input_flags)
		# local affixes are added as string to "to_be_processed" array
		# TODO turn this array into a more elegant database array, reduce string splitting / processing?
		local_prefixes = ""
		local_suffixes = ""
		for (i in separated_flags_array) {
			if (separated_flags_array[i] " 1 delete" in suffix_db) local_suffixes = local_suffixes separated_flags_array[i]  (flag_type=="num" ? "," : "" );
			else if (separated_flags_array[i] " 1 delete" in prefix_db) local_prefixes = local_prefixes separated_flags_array[i]  (flag_type=="num" ? "," : "" );
		}
		# group the words suffixes and prefixes together in arrays
		for (i in separated_flags_array) {
			# check if flag exists in prefix / suffix database array by searching for an
			# element that must exist if the flag rule entry exists in the db i.e. "delete"
			if (separated_flags_array[i] " 1 delete" in suffix_db && ((location !~ "5$" && !complex_prefixes) || (location !~ "4$" && complex_prefixes)) ) {
				for (j=1; separated_flags_array[i] " " j " delete" in suffix_db; j++) {
					if (word ~ suffix_db[separated_flags_array[i] " " j " requires"]) {
						if (apply_suffix(word, affix_level, location, separated_flags_array[i] " " j)) return_value = 1;
						debug("stem \"" word "\" matches flag " separated_flags_array[i] "(" j ") with regex " suffix_db[separated_flags_array[i] " " j " requires"] " made word " affixed_word)
						if (local_prefixes) {
							return_value = 1
							sandwich_location = location (location ~ "3$" ? 4 : 5)
							to_be_processed[affixed_word "/" local_prefixes "/" sandwich_location "/" affix_level] = 1
							debug("\t(from suffix) sandwich prefixing: " affixed_word "/" local_prefixes "/" sandwich_location "/" affix_level)
						}
					}
				}
			}
			else if (separated_flags_array[i] " 1 delete" in prefix_db && ((location !~ "^1" && complex_prefixes) || (location !~ "^2" && !complex_prefixes)) ) {
				for (j=1; separated_flags_array[i] " " j " delete" in prefix_db; j++) {
					if (word ~ prefix_db[separated_flags_array[i] " " j " requires"]) {
						if (apply_prefix(word, affix_level, location, separated_flags_array[i] " " j)) return_value = 1;
						debug("stem \"" word "\" matches flag " separated_flags_array[i] "(" j ") with regex " prefix_db[separated_flags_array[i] " " j " requires"] " made word " affixed_word)
						if (local_suffixes) {
							return_value = 1
							sandwich_location = (location ~ "^3" ? 2 : 1) location
							to_be_processed[affixed_word "/" local_suffixes "/" sandwich_location "/" affix_level] = 1
							debug("\t(from prefix) sandwich suffixing: " affixed_word "/" local_suffixes "/" sandwich_location "/" affix_level)
						}
					}
				}
			}
		}
		# cut off the last "," added to a string of flags of type "num"
		if (flag_type == "num") {
			local_suffixes = substr(local_suffixes, 1, length(local_suffixes) - 1)
			local_prefixes = substr(local_prefixes, 1, length(local_prefixes) - 1)
		}
		debug("END AFFIX_WORD")
		return return_value
	}

	function apply_suffix(word, affix_level, local_location, rule,	return_value) {
		cut_chars = (suffix_db[rule " delete"] == "0" ? 0 : length(suffix_db[rule " delete"]))
		affixed_word = substr(word, 1, length(word) - cut_chars) (suffix_db[rule " add"] == "0" ? "": suffix_db[rule " add"])
		all_variations[affixed_word] = affixed_word
		if (rule " flags" in suffix_db) {
			return_value = 1
			if (local_location ~ "4$") local_location = local_location "5";
			else if (local_location ~ "3$") local_location = local_location "4";
			to_be_processed[affixed_word "/" suffix_db[rule " flags"] "/" local_location "/" affix_level + 1] = 1
		}
		return return_value
	}

	function apply_prefix(word, affix_level, local_location, rule,	return_value) {
		cut_chars = (prefix_db[rule " delete"] == "0" ? 0 : length(prefix_db[rule " delete"]))
		affixed_word = (prefix_db[rule " add"] == "0" ? "": prefix_db[rule " add"]) substr(word, cut_chars+1)
		all_variations[affixed_word] = affixed_word
		if (rule " flags" in prefix_db) {
			return_value = 1
			if (local_location ~ "^2") local_location = "1" local_location;
			else if (local_location ~ "^3") local_location = "2" local_location;
			to_be_processed[affixed_word "/" prefix_db[rule " flags"] "/" local_location "/" affix_level + 1] = 1
		}
		return return_value
	}
	
	# get some .aff settings to help configure the affixed word generation
	NR==FNR && $1=="COMPLEXPREFIXES" { complex_prefixes = "yes"; next }
	NR==FNR && $1=="FLAG" { flag_type = $2; next }
	
	# save all prefixes to the database
	NR==FNR && $1=="PFX" && fx!=1 && NF>4 && $4!~"[1-9][0-9]*" {
		if ($2 in prefix_name_to_rule_length) prefix_name_to_rule_length[$2] = prefix_name_to_rule_length[$2] + 1;
		else prefix_name_to_rule_length[$2] = 1;
		i = prefix_name_to_rule_length[$2]
		split($4, a_f, "/")
		prefix_db[$2 " " i " delete"] = $3
		prefix_db[$2 " " i " add"] = a_f[1]
		if (2 in a_f) {
			prefix_db[$2 " " i " flags"] = a_f[2]
			separate_flags(a_f[2])
			for (flag in separated_flags_array) {
				referenced_affix_names[separated_flags_array[flag]] = separated_flags_array[flag]
			}
		}
		prefix_db[$2 " " i " requires"] = "^"$5
		next
	}

	# save all suffixes to the database
	NR==FNR && $1=="SFX" && fx!=2 && NF>4 && $4!~"[1-9][0-9]*" {
		if ($2 in suffix_name_to_rule_length) suffix_name_to_rule_length[$2] = suffix_name_to_rule_length[$2] + 1;
		else suffix_name_to_rule_length[$2] = 1;
		i = suffix_name_to_rule_length[$2]
		split($4, a_f, "/")
		suffix_db[$2 " " i " delete"] = $3
		suffix_db[$2 " " i " add"] = a_f[1]
		if (2 in a_f) {
			suffix_db[$2 " " i " flags"] = a_f[2]
			separate_flags(a_f[2])
			for (flag in separated_flags_array) {
				referenced_affix_names[separated_flags_array[flag]] = separated_flags_array[flag]
			}
		}
		suffix_db[$2 " " i " requires"] = $5"$"
		next
	}

	NR!=FNR && FNR==1 {
		# do anything required at the end of the aff file / beginning of dic file
		if (number_of_entries >= 100) print_to_terminal("Generating all words in the dictionary... 0%");
	}
	
	NR!=FNR && (FNR-1)>=int(next_update) && number_of_entries>=100 {
		percent_complete += 1
		next_update = entry_step_per_percent*(percent_complete+1)
		print_to_terminal("\r\033[0KGenerating all words in the dictionary... " percent_complete "%")
		if (percent_complete == 100) print_to_terminal("\n");
	}

	NR!=FNR && FNR>1 {
		# strips out anything on the line that follows a tab
		# tries to strip comments out too i.e. starting with " #"
		split($0, e_, "\t")
		split(e_[1], e, " #")
		split(e[1], entry_and_flags, "/")
		all_variations[entry_and_flags[1]] = entry_and_flags[1]
		# check if dic entry has flags
		if (2 in entry_and_flags) {
			to_be_processed[e[1] "/3/1"] = 1
			process = 1
			while (process) {
				process = 0
				for (entry in to_be_processed) {
					split(entry, entry_data, "/")
					# if data includes flags (#2) and no. flags applied (#4) is below four
					if (length(entry_data) > 3 && entry_data[4] < 4) {
						if (affix_word(entry_data[1], entry_data[2], entry_data[3], entry_data[4])) process = 1;
					}
					else {
						process = 1
						all_variations[entry_data[1]] = entry_data[1]
						delete to_be_processed[entry]
					}
				}
			}
		}
		next
	}
	
	END {
		if (number_of_entries >= 100) print_to_terminal("Sending entries to Hunspell...\n");
		for (variation in all_variations) {
			print(all_variations[variation])
		}
		if (number_of_entries >= 100) print_to_terminal("Spellchecking entries...\n");
	}
	' $1 $2
}

# this switches whether to print only suffixed (fx = 1),
# prefixed (fx = 2) or all forms (fx = 0) of a stem.
# -g ignores the -s and -p and generates all forms
fx=0
generate_all_words=false
case $1 in
	-s) fx=1 ; shift;;
	-p) fx=2 ; shift;;
	-g) generate_all_words=true ; shift;;
	*)  [ ! -e "$PWD/$1" ] && print_help_and_exit;;
esac

# check if there are the correct remaining arguments
[ $# -eq 3 ] || print_help_and_exit

# check that the relevant files exist
if [ ! -e "$PWD/$1" ] ; then echo "wordforms: Affix file $PWD/$1 does not exist." ; exit 1 ; fi
if [ ! -e "$PWD/$2" ] ; then echo "wordforms: Dictionary file $PWD/$2 does not exist." ; exit 1 ; fi

# clear any previous temporary dictionary
test -h /tmp/wordforms.aff && rm /tmp/wordforms.aff
rm -f /tmp/wordforms.dic
# make a symbolic link of the aff file
ln -s "$PWD/$1" /tmp/wordforms.aff

if [ "$generate_all_words" = true ] ; then
	# find all words in the dictionary that can be
	# generated by affixing the stems in the dic file
	# with the rules in the aff file
	
	# make a symbolic link of the dic file
	ln -s "$PWD/$2" /tmp/wordforms.dic
	
	generate /tmp/wordforms.aff /tmp/wordforms.dic | hunspell -d /tmp/wordforms -G -l | sort -u > $3
else
	# find all lines exactly matching the search
	# stem given in the command line arguments,
	# plus optional forward slash and flags.
	# does not filter for comments or other data
	# in lines - these are copied into the temp
	# dic and filtered out in the main awk script
	# in the function generate()
	awk -v stem="$3" '
	BEGIN { stems_found = "" }
	$0~"^"stem"[/$]" || $0==stem { stems_found = "yes" ; stems[$0] = $0 }
	END {
		if (stems_found) {
			print(length(stems))
			for (s in stems) {
				print(stems[s])
			}
		}
		else {
			exit 1
		}
	}
	' "$PWD/$2" > /tmp/wordforms.dic

	# if no matching stems have been found then exit;
	# theres no need to run the main word generation code
	if [ $? -ne 0 ] ; then exit 1 ; fi
	
	generate /tmp/wordforms.aff /tmp/wordforms.dic | sort -u
fi