PhutilArgumentSpellingCorrector.php
246e604a070fmaster

PhutilArgumentSpellingCorrector.php
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			<?php

			final class PhutilArgumentSpellingCorrector extends Phobject {

			private $editDistanceMatrix;
			private $maximumDistance;
			private $mode;

			const MODE_COMMANDS = 'commands';
			const MODE_FLAGS = 'flags';

			/**
			* Build a new corrector with parameters for correcting commands, like
			* fixing "dfif" into "diff" in "arc diff".
			*
			* @return PhutilArgumentSpellingCorrector Configured corrector.
			*/
			public static function newCommandCorrector() {
			// When correcting argument spelling, we're relatively liberal about
			// selecting alternatives and allow multiple mistakes.
			$max_distance = 2;

			// Adjust to the scaled edit costs we use below, so "2" roughly means
			// "2 edits".
			$max_distance = $max_distance * 3;

			// These costs are somewhat made up, but the theory is that it is far more
			// likely you will mis-strike a key ("lans" for "land") or press two keys
			// out of order ("alnd" for "land") than omit keys or press extra keys.
			$matrix = id(new PhutilEditDistanceMatrix())
			->setInsertCost(4)
			->setDeleteCost(4)
			->setReplaceCost(3)
			->setTransposeCost(2);

			return id(new self())
			->setEditDistanceMatrix($matrix)
			->setMode(self::MODE_COMMANDS)
			->setMaximumDistance($max_distance);
			}


			/**
			* Build a new corrector with parameters for correcting flags, like
			* fixing "--nolint" into "--no-lint".
			*
			* @return PhutilArgumentSpellingCorrector Configured corrector.
			*/
			public static function newFlagCorrector() {
			// When correcting flag spelling, we're stricter than we are when
			// correcting command spelling: we allow only one inserted or deleted
			// character. It is mainly to handle cases like "--no-lint" versus
			// "--nolint" or "--reviewer" versus "--reviewers".
			$max_distance = 1;

			$matrix = id(new PhutilEditDistanceMatrix())
			->setInsertCost(1)
			->setDeleteCost(1)
			->setReplaceCost(10);

			return id(new self())
			->setEditDistanceMatrix($matrix)
			->setMode(self::MODE_FLAGS)
			->setMaximumDistance($max_distance);
			}

			public function setMode($mode) {
			$this->mode = $mode;
			return $this;
			}

			public function getMode() {
			return $this->mode;
			}

			public function setEditDistanceMatrix(PhutilEditDistanceMatrix $matrix) {
			$this->editDistanceMatrix = $matrix;
			return $this;
			}

			public function getEditDistanceMatrix() {
			return $this->editDistanceMatrix;
			}

			public function setMaximumDistance($maximum_distance) {
			$this->maximumDistance = $maximum_distance;
			return $this;
			}

			public function getMaximumDistance() {
			return $this->maximumDistance;
			}

			public function correctSpelling($input, array $options) {
			$matrix = $this->getEditDistanceMatrix();
			if (!$matrix) {
			throw new PhutilInvalidStateException('setEditDistanceMatrix');
			}

			$max_distance = $this->getMaximumDistance();
			if (!$max_distance) {
			throw new PhutilInvalidStateException('setMaximumDistance');
			}

			// If we're correcting commands, never correct an input which begins
			// with "-", since this is almost certainly intended to be a flag.
			if ($this->getMode() === self::MODE_COMMANDS) {
			if (preg_match('/^-/', $input)) {
			return array();
			}
			}

			$input = $this->normalizeString($input);
			foreach ($options as $key => $option) {
			$options[$key] = $this->normalizeString($option);
			}

			// In command mode, accept any unique prefix of a command as a shorthand
			// for that command.
			if ($this->getMode() === self::MODE_COMMANDS) {
			$prefixes = array();
			foreach ($options as $option) {
			if (!strncmp($input, $option, strlen($input))) {
			$prefixes[] = $option;
			}
			}

			if (count($prefixes) === 1) {
			return $prefixes;
			}
			}

			$distances = array();
			$inputv = phutil_utf8v($input);
			foreach ($options as $option) {
			$optionv = phutil_utf8v($option);
			$matrix->setSequences($optionv, $inputv);
			$distances[$option] = $matrix->getEditDistance();
			}

			asort($distances);
			$best = min($max_distance, head($distances));
			foreach ($distances as $option => $distance) {
			if ($distance > $best) {
			unset($distances[$option]);
			}
			}

			// Before filtering, check if we have multiple equidistant matches and
			// return them if we do. This prevents us from, e.g., matching "alnd" with
			// both "land" and "amend", then dropping "land" for being too short, and
			// incorrectly completing to "amend".
			if (count($distances) > 1) {
			return array_keys($distances);
			}

			foreach ($distances as $option => $distance) {
			if (phutil_utf8_strlen($option) < $distance) {
			unset($distances[$option]);
			}
			}

			return array_keys($distances);
			}

			private function normalizeString($string) {
			return phutil_utf8_strtolower($string);
			}

			}

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rARC/src/parser/argument/PhutilArgumentSpellingCorrector.php246e604a070fmaster

PhutilArgumentSpellingCorrector.phpView Options

Owner Packages

rARC/src/parser/argument/PhutilArgumentSpellingCorrector.php
246e604a070fmaster

PhutilArgumentSpellingCorrector.php
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