ADDED src/0dev.org/bits/bits.go Index: src/0dev.org/bits/bits.go ================================================================== --- /dev/null +++ src/0dev.org/bits/bits.go @@ -0,0 +1,92 @@ +// Package bits provides a bit vector backed with uints +package bits + +import ( + "strconv" +) + +// The Vector interface defines methods on the bit vector +type Vector interface { + // Retrieves the bit at the designated position + Peek(uint) bool + // Sets the bit at the designated position + Poke(uint, bool) + // Flips the bit at the designated position + Flip(uint) + // Returns the total number of elements supported by the vector + Len() uint +} + +type boolvector []bool + +// Retrieves the bit at the designated position +func (v boolvector) Peek(pos uint) bool { + return v[pos] +} + +// Sets the bit at the designated position +func (v boolvector) Poke(pos uint, val bool) { + v[pos] = val +} + +// Flips the bit at the designated position +func (v boolvector) Flip(pos uint) { + v[pos] = !v[pos] +} + +// Returns the total number of elements supported by the vector +func (v boolvector) Len() uint { + return uint(len(v)) +} + +type vector []uint + +// Retrieves the bit at the designated position +func (v vector) Peek(pos uint) bool { + var slot, offset uint = at(pos) + return (v[slot] & (1 << offset)) > 0 +} + +// Sets the bit at the designated position +func (v vector) Poke(pos uint, val bool) { + var slot, offset uint = at(pos) + if val { + v[slot] |= (1 << offset) + } else { + v[slot] &^= (1 << offset) + } +} + +// Flips the bit at the designated position +func (v vector) Flip(pos uint) { + var slot, offset uint = at(pos) + v[slot] ^= (1 << offset) +} + +// Returns the total number of elements supported by the vector +func (v vector) Len() uint { + return uint(len(v) * strconv.IntSize) +} + +func at(pos uint) (uint, uint) { + return pos / strconv.IntSize, pos % strconv.IntSize +} + +// Create a new bit vector sized up to the desired number of elements +func New(size uint) Vector { + var length uint = size / strconv.IntSize + + if size%strconv.IntSize > 0 { + // Allocate one additional slot if the desired + // size is does not divide by 32/64 + length++ + } + + var slice []uint = make([]uint, length) + return vector(slice) +} + +func NewBool(size uint) Vector { + var slice []bool = make([]bool, size) + return boolvector(slice) +} ADDED src/0dev.org/bits/bits_test.go Index: src/0dev.org/bits/bits_test.go ================================================================== --- /dev/null +++ src/0dev.org/bits/bits_test.go @@ -0,0 +1,65 @@ +package bits + +import ( + "strconv" + "testing" +) + +func TestSize(t *testing.T) { + sizes := []uint{0, 31, 32, 33, 61, 63, 64, 127, 128, 129} + + for _, size := range sizes { + v := New(size) + if v.Len() < size || v.Len() > size+strconv.IntSize { + t.Error("Invalid length", v.Len(), "expected", size) + } + } +} + +func TestEmpty(t *testing.T) { + var size uint = 128 + v := New(size) + + // Check if it is empty by default + for i := uint(0); i < size; i++ { + if v.Peek(i) { + t.Error("Invalid raised bit at", i) + } + } +} + +func TestBasic(t *testing.T) { + var size uint = 128 + v := New(size) + + // Raise and lower each position explicitly + for i := uint(0); i < size; i++ { + v.Poke(i, true) + if !v.Peek(i) { + t.Error("Invalid lowered bit at", i) + } + + v.Poke(i, false) + if v.Peek(i) { + t.Error("Invalid raised bit at", i) + } + } +} + +func TestFlip(t *testing.T) { + var size uint = 128 + v := New(size) + + // Raise and lower each position by flipping + for i := uint(0); i < size; i++ { + v.Flip(i) + if !v.Peek(i) { + t.Error("Invalid lowered bit at", i) + } + + v.Flip(i) + if v.Peek(i) { + t.Error("Invalid raised bit at", i) + } + } +} ADDED src/0dev.org/commands/plaindiff/main.go Index: src/0dev.org/commands/plaindiff/main.go ================================================================== --- /dev/null +++ src/0dev.org/commands/plaindiff/main.go @@ -0,0 +1,165 @@ +package main + +import ( + diff "0dev.org/diff" + "bufio" + "flag" + "fmt" + "hash" + "hash/fnv" + "io" + "os" +) + +const usage = "Usage: plaindiff " + +func main() { + flag.Parse() + + var args []string = flag.Args() + if len(args) != 2 { + os.Stderr.WriteString(usage) + os.Exit(1) + } + + var hd hashDiff + hd.hash = fnv.New64a() + hd.first = read(args[0], hd.hash) + hd.second = read(args[1], hd.hash) + + var result diff.Delta = diff.Diff(&hd) + //var marks []diff.Mark = make([]diff.Mark, len(result.Added)+len(result.Removed)) + + //var added, removed []diff.Mark = result.Added, result.Removed + fmt.Println(result) + + gen := source(result) + for have, added, mark := gen(); have; have, added, mark = gen() { + var from []line + if added { + from = hd.second + } else { + from = hd.first + } + + fmt.Println() + for i := mark.From; i < mark.Length; i++ { + fmt.Print(i) + if added { + fmt.Print(" > ") + } else { + fmt.Print(" < ") + } + fmt.Println(from[i].text) + } + } + +} + +func source(d diff.Delta) func() (bool, bool, diff.Mark) { + var addedAt, removedAt int = 0, 0 + return func() (bool, bool, diff.Mark) { + var addsOver bool = addedAt == len(d.Added) + var removesOver bool = removedAt == len(d.Removed) + + var add, remove diff.Mark + + // Check whether both mark slices have been exhausted + if addsOver && removesOver { + return false, false, diff.Mark{} + } + + // Return an add if removes are over + if removesOver { + add = d.Added[addedAt] + addedAt++ + return true, true, add + } + + // Return a remove if the adds are over + if addsOver { + remove = d.Removed[removedAt] + removedAt++ + return true, false, remove + } + + add = d.Added[addedAt] + remove = d.Removed[removedAt] + + // Prioritize a remove if it happens before an add + if remove.From <= add.From { + removedAt++ + return true, false, remove + } + + // Else + addedAt++ + return true, true, add + + } +} + +// A line-based diff.Interface implementation +type hashDiff struct { + first, second []line + hash hash.Hash64 +} + +func (h *hashDiff) Equal(i, j int) bool { + // return h.first[i].text == h.second[j].text + if h.first[i].hash != h.second[j].hash { + return false + } else { + return h.first[i].text == h.second[j].text + } +} + +func (h *hashDiff) Len() (int, int) { + return len(h.first), len(h.second) +} + +type line struct { + hash uint64 + text string +} + +// Reads all lines in a file and returns a line entry for each +func read(name string, h hash.Hash64) []line { + var f *os.File + var e error + + f, e = os.Open(name) + fatal(e) + + var result []line = lines(f, h) + fatal(f.Close()) + + return result +} + +// Reads all lines and returns a line entry for each +func lines(r io.Reader, h hash.Hash64) []line { + var scanner *bufio.Scanner = bufio.NewScanner(r) + var result []line = make([]line, 0) + for scanner.Scan() { + h.Reset() + h.Write(scanner.Bytes()) + result = append(result, line{hash: h.Sum64(), text: scanner.Text()}) + } + return result +} + +// Write an error to stderr +func stderr(e error) { + if e != nil { + os.Stderr.WriteString(e.Error()) + } +} + +// Write an error to stderr and exit +func fatal(e error) { + if e != nil { + stderr(e) + os.Exit(1) + } +} ADDED src/0dev.org/commands/plaindiff/rime1.txt Index: src/0dev.org/commands/plaindiff/rime1.txt ================================================================== --- /dev/null +++ src/0dev.org/commands/plaindiff/rime1.txt @@ -0,0 +1,780 @@ +It is an ancient Mariner, +And he stoppeth one of three. +'By thy long grey beard and glittering eye, +Now wherefore stopp'st thou me? + +The Bridegroom's doors are opened wide, +And I am next of kin; +The guests are met, the feast is set: +May'st hear the merry din.' + +He holds him with his skinny hand, +'There was a ship,' quoth he. +'Hold off! unhand me, grey-beard loon!' +Eftsoons his hand dropt he. + +He holds him with his glittering eye— +The Wedding-Guest stood still, +And listens like a three years' child: +The Mariner hath his will. + +The Wedding-Guest sat on a stone: +He cannot choose but hear; +And thus spake on that ancient man, +The bright-eyed Mariner. + +'The ship was cheered, the harbour cleared, +Merrily did we drop +Below the kirk, below the hill, +Below the lighthouse top. + +The Sun came up upon the left, +Out of the sea came he! +And he shone bright, and on the right +Went down into the sea. + +Higher and higher every day, +Till over the mast at noon—' +The Wedding-Guest here beat his breast, +For he heard the loud bassoon. + +The bride hath paced into the hall, +Red as a rose is she; +Nodding their heads before her goes +The merry minstrelsy. + +The Wedding-Guest he beat his breast, +Yet he cannot choose but hear; +And thus spake on that ancient man, +The bright-eyed Mariner. + +And now the STORM-BLAST came, and he +Was tyrannous and strong: +He struck with his o'ertaking wings, +And chased us south along. + +With sloping masts and dipping prow, +As who pursued with yell and blow +Still treads the shadow of his foe, +And forward bends his head, +The ship drove fast, loud roared the blast, +And southward aye we fled. + +And now there came both mist and snow, +And it grew wondrous cold: +And ice, mast-high, came floating by, +As green as emerald. + +And through the drifts the snowy clifts +Did send a dismal sheen: +Nor shapes of men nor beasts we ken— +The ice was all between. + +The ice was here, the ice was there, +The ice was all around: +It cracked and growled, and roared and howled, +Like noises in a swound! + +At length did cross an Albatross, +Thorough the fog it came; +As if it had been a Christian soul, +We hailed it in God's name. + +It ate the food it ne'er had eat, +And round and round it flew. +The ice did split with a thunder-fit; +The helmsman steered us through! + +And a good south wind sprung up behind; +The Albatross did follow, +And every day, for food or play, +Came to the mariner's hollo! + +In mist or cloud, on mast or shroud, +It perched for vespers nine; +Whiles all the night, through fog-smoke white, +Glimmered the white Moon-shine.' + +'God save thee, ancient Mariner! +From the fiends, that plague thee thus!— +Why look'st thou so?'—With my cross-bow +I shot the ALBATROSS. + +PART II +The Sun now rose upon the right: +Out of the sea came he, +Still hid in mist, and on the left +Went down into the sea. + +And the good south wind still blew behind, +But no sweet bird did follow, +Nor any day for food or play +Came to the mariner's hollo! + +And I had done a hellish thing, +And it would work 'em woe: +For all averred, I had killed the bird +That made the breeze to blow. +Ah wretch! said they, the bird to slay, +That made the breeze to blow! + +Nor dim nor red, like God's own head, +The glorious Sun uprist: +Then all averred, I had killed the bird +That brought the fog and mist. +'Twas right, said they, such birds to slay, +That bring the fog and mist. + +The fair breeze blew, the white foam flew, +The furrow followed free; +We were the first that ever burst +Into that silent sea. + +Down dropt the breeze, the sails dropt down, +'Twas sad as sad could be; +And we did speak only to break +The silence of the sea! + +All in a hot and copper sky, +The bloody Sun, at noon, +Right up above the mast did stand, +No bigger than the Moon. + +Day after day, day after day, +We stuck, nor breath nor motion; +As idle as a painted ship +Upon a painted ocean. + +Water, water, every where, +And all the boards did shrink; +Water, water, every where, +Nor any drop to drink. + +The very deep did rot: O Christ! +That ever this should be! +Yea, slimy things did crawl with legs +Upon the slimy sea. + +About, about, in reel and rout +The death-fires danced at night; +The water, like a witch's oils, +Burnt green, and blue and white. + +And some in dreams assurèd were +Of the Spirit that plagued us so; +Nine fathom deep he had followed us +From the land of mist and snow. + +And every tongue, through utter drought, +Was withered at the root; +We could not speak, no more than if +We had been choked with soot. + +Ah! well a-day! what evil looks +Had I from old and young! +Instead of the cross, the Albatross +About my neck was hung. + +PART III +There passed a weary time. Each throat +Was parched, and glazed each eye. +A weary time! a weary time! +How glazed each weary eye, + +When looking westward, I beheld +A something in the sky. + +At first it seemed a little speck, +And then it seemed a mist; +It moved and moved, and took at last +A certain shape, I wist. + +A speck, a mist, a shape, I wist! +And still it neared and neared: +As if it dodged a water-sprite, +It plunged and tacked and veered. + +With throats unslaked, with black lips baked, +We could nor laugh nor wail; +Through utter drought all dumb we stood! +I bit my arm, I sucked the blood, +And cried, A sail! a sail! + +With throats unslaked, with black lips baked, +Agape they heard me call: +Gramercy! they for joy did grin, +And all at once their breath drew in. +As they were drinking all. + +See! see! (I cried) she tacks no more! +Hither to work us weal; +Without a breeze, without a tide, +She steadies with upright keel! + +The western wave was all a-flame. +The day was well nigh done! +Almost upon the western wave +Rested the broad bright Sun; +When that strange shape drove suddenly +Betwixt us and the Sun. + +And straight the Sun was flecked with bars, +(Heaven's Mother send us grace!) +As if through a dungeon-grate he peered +With broad and burning face. + +Alas! (thought I, and my heart beat loud) +How fast she nears and nears! +Are those her sails that glance in the Sun, +Like restless gossameres? + +Are those her ribs through which the Sun +Did peer, as through a grate? +And is that Woman all her crew? +Is that a DEATH? and are there two? +Is DEATH that woman's mate? + +Her lips were red, her looks were free, +Her locks were yellow as gold: +Her skin was as white as leprosy, +The Night-mare LIFE-IN-DEATH was she, +Who thicks man's blood with cold. + +The naked hulk alongside came, +And the twain were casting dice; +'The game is done! I've won! I've won!' +Quoth she, and whistles thrice. + +The Sun's rim dips; the stars rush out; +At one stride comes the dark; +With far-heard whisper, o'er the sea, +Off shot the spectre-bark. + +We listened and looked sideways up! +Fear at my heart, as at a cup, +My life-blood seemed to sip! +The stars were dim, and thick the night, +The steersman's face by his lamp gleamed white; +From the sails the dew did drip— +Till clomb above the eastern bar +The hornèd Moon, with one bright star +Within the nether tip. + +One after one, by the star-dogged Moon, +Too quick for groan or sigh, +Each turned his face with a ghastly pang, +And cursed me with his eye. + +Four times fifty living men, +(And I heard nor sigh nor groan) +With heavy thump, a lifeless lump, +They dropped down one by one. + +The souls did from their bodies fly,— +They fled to bliss or woe! +And every soul, it passed me by, +Like the whizz of my cross-bow! + +PART IV +'I fear thee, ancient Mariner! +I fear thy skinny hand! +And thou art long, and lank, and brown, +As is the ribbed sea-sand. + +I fear thee and thy glittering eye, +And thy skinny hand, so brown.'— +Fear not, fear not, thou Wedding-Guest! +This body dropt not down. + +Alone, alone, all, all alone, +Alone on a wide wide sea! +And never a saint took pity on +My soul in agony. + +The many men, so beautiful! +And they all dead did lie: +And a thousand thousand slimy things +Lived on; and so did I. + +I looked upon the rotting sea, +And drew my eyes away; +I looked upon the rotting deck, +And there the dead men lay. + +I looked to heaven, and tried to pray; +But or ever a prayer had gusht, +A wicked whisper came, and made +My heart as dry as dust. + +I closed my lids, and kept them close, +And the balls like pulses beat; +For the sky and the sea, and the sea and the sky +Lay dead like a load on my weary eye, +And the dead were at my feet. + +The cold sweat melted from their limbs, +Nor rot nor reek did they: +The look with which they looked on me +Had never passed away. + +An orphan's curse would drag to hell +A spirit from on high; +But oh! more horrible than that +Is the curse in a dead man's eye! +Seven days, seven nights, I saw that curse, +And yet I could not die. + +The moving Moon went up the sky, +And no where did abide: +Softly she was going up, +And a star or two beside— + +Her beams bemocked the sultry main, +Like April hoar-frost spread; +But where the ship's huge shadow lay, +The charmèd water burnt alway +A still and awful red. + +Beyond the shadow of the ship, +I watched the water-snakes: +They moved in tracks of shining white, +And when they reared, the elfish light +Fell off in hoary flakes. + +Within the shadow of the ship +I watched their rich attire: +Blue, glossy green, and velvet black, +They coiled and swam; and every track +Was a flash of golden fire. + +O happy living things! no tongue +Their beauty might declare: +A spring of love gushed from my heart, +And I blessed them unaware: +Sure my kind saint took pity on me, +And I blessed them unaware. + +The self-same moment I could pray; +And from my neck so free +The Albatross fell off, and sank +Like lead into the sea. + +PART V +Oh sleep! it is a gentle thing, +Beloved from pole to pole! +To Mary Queen the praise be given! +She sent the gentle sleep from Heaven, +That slid into my soul. + +The silly buckets on the deck, +That had so long remained, +I dreamt that they were filled with dew; +And when I awoke, it rained. + +My lips were wet, my throat was cold, +My garments all were dank; +Sure I had drunken in my dreams, +And still my body drank. + +I moved, and could not feel my limbs: +I was so light—almost +I thought that I had died in sleep, +And was a blessed ghost. + +And soon I heard a roaring wind: +It did not come anear; +But with its sound it shook the sails, +That were so thin and sere. + +The upper air burst into life! +And a hundred fire-flags sheen, +To and fro they were hurried about! +And to and fro, and in and out, +The wan stars danced between. + +And the coming wind did roar more loud, +And the sails did sigh like sedge, +And the rain poured down from one black cloud; +The Moon was at its edge. + +The thick black cloud was cleft, and still +The Moon was at its side: +Like waters shot from some high crag, +The lightning fell with never a jag, +A river steep and wide. + +The loud wind never reached the ship, +Yet now the ship moved on! +Beneath the lightning and the Moon +The dead men gave a groan. + +They groaned, they stirred, they all uprose, +Nor spake, nor moved their eyes; +It had been strange, even in a dream, +To have seen those dead men rise. + +The helmsman steered, the ship moved on; +Yet never a breeze up-blew; +The mariners all 'gan work the ropes, +Where they were wont to do; +They raised their limbs like lifeless tools— +We were a ghastly crew. + +The body of my brother's son +Stood by me, knee to knee: +The body and I pulled at one rope, +But he said nought to me. + +'I fear thee, ancient Mariner!' +Be calm, thou Wedding-Guest! +'Twas not those souls that fled in pain, +Which to their corses came again, +But a troop of spirits blest: + +For when it dawned—they dropped their arms, +And clustered round the mast; +Sweet sounds rose slowly through their mouths, +And from their bodies passed. + +Around, around, flew each sweet sound, +Then darted to the Sun; +Slowly the sounds came back again, +Now mixed, now one by one. + +Sometimes a-dropping from the sky +I heard the sky-lark sing; +Sometimes all little birds that are, +How they seemed to fill the sea and air +With their sweet jargoning! + +And now 'twas like all instruments, +Now like a lonely flute; +And now it is an angel's song, +That makes the heavens be mute. + +It ceased; yet still the sails made on +A pleasant noise till noon, +A noise like of a hidden brook +In the leafy month of June, +That to the sleeping woods all night +Singeth a quiet tune. + +Till noon we quietly sailed on, +Yet never a breeze did breathe: +Slowly and smoothly went the ship, +Moved onward from beneath. + +Under the keel nine fathom deep, +From the land of mist and snow, +The spirit slid: and it was he +That made the ship to go. +The sails at noon left off their tune, +And the ship stood still also. + +The Sun, right up above the mast, +Had fixed her to the ocean: +But in a minute she 'gan stir, +With a short uneasy motion— +Backwards and forwards half her length +With a short uneasy motion. + +Then like a pawing horse let go, +She made a sudden bound: +It flung the blood into my head, +And I fell down in a swound. + +How long in that same fit I lay, +I have not to declare; +But ere my living life returned, +I heard and in my soul discerned +Two voices in the air. + +'Is it he?' quoth one, 'Is this the man? +By him who died on cross, +With his cruel bow he laid full low +The harmless Albatross. + +The spirit who bideth by himself +In the land of mist and snow, +He loved the bird that loved the man +Who shot him with his bow.' + +The other was a softer voice, +As soft as honey-dew: +Quoth he, 'The man hath penance done, +And penance more will do.' + +PART VI + +First Voice +'But tell me, tell me! speak again, +Thy soft response renewing— +What makes that ship drive on so fast? +What is the ocean doing?' + +Second Voice +Still as a slave before his lord, +The ocean hath no blast; +His great bright eye most silently +Up to the Moon is cast— + +If he may know which way to go; +For she guides him smooth or grim. +See, brother, see! how graciously +She looketh down on him.' + +First Voice +'But why drives on that ship so fast, +Without or wave or wind?' + +Second Voice +'The air is cut away before, +And closes from behind. + +Fly, brother, fly! more high, more high! +Or we shall be belated: +For slow and slow that ship will go, +When the Mariner's trance is abated.' + +I woke, and we were sailing on +As in a gentle weather: +'Twas night, calm night, the moon was high; +The dead men stood together. + +All stood together on the deck, +For a charnel-dungeon fitter: +All fixed on me their stony eyes, +That in the Moon did glitter. + +The pang, the curse, with which they died, +Had never passed away: +I could not draw my eyes from theirs, +Nor turn them up to pray. + +And now this spell was snapt: once more +I viewed the ocean green, +And looked far forth, yet little saw +Of what had else been seen— + +Like one, that on a lonesome road +Doth walk in fear and dread, +And having once turned round walks on, +And turns no more his head; +Because he knows, a frightful fiend +Doth close behind him tread. + +But soon there breathed a wind on me, +Nor sound nor motion made: +Its path was not upon the sea, +In ripple or in shade. + +It raised my hair, it fanned my cheek +Like a meadow-gale of spring— +It mingled strangely with my fears, +Yet it felt like a welcoming. + +Swiftly, swiftly flew the ship, +Yet she sailed softly too: +Sweetly, sweetly blew the breeze— +On me alone it blew. + +Oh! dream of joy! is this indeed +The light-house top I see? +Is this the hill? is this the kirk? +Is this mine own countree? + +We drifted o'er the harbour-bar, +And I with sobs did pray— +O let me be awake, my God! +Or let me sleep alway. + +The harbour-bay was clear as glass, +So smoothly it was strewn! +And on the bay the moonlight lay, +And the shadow of the Moon. + +The rock shone bright, the kirk no less, +That stands above the rock: +The moonlight steeped in silentness +The steady weathercock. + +And the bay was white with silent light, +Till rising from the same, +Full many shapes, that shadows were, +In crimson colours came. + +A little distance from the prow +Those crimson shadows were: +I turned my eyes upon the deck— +Oh, Christ! what saw I there! + +Each corse lay flat, lifeless and flat, +And, by the holy rood! +A man all light, a seraph-man, +On every corse there stood. + +This seraph-band, each waved his hand: +It was a heavenly sight! +They stood as signals to the land, +Each one a lovely light; + +This seraph-band, each waved his hand, +No voice did they impart— +No voice; but oh! the silence sank +Like music on my heart. + +But soon I heard the dash of oars, +I heard the Pilot's cheer; +My head was turned perforce away +And I saw a boat appear. + +The Pilot and the Pilot's boy, +I heard them coming fast: +Dear Lord in Heaven! it was a joy +The dead men could not blast. + +I saw a third—I heard his voice: +It is the Hermit good! +He singeth loud his godly hymns +That he makes in the wood. +He'll shrieve my soul, he'll wash away +The Albatross's blood. + +PART VII +This Hermit good lives in that wood +Which slopes down to the sea. +How loudly his sweet voice he rears! +He loves to talk with marineres +That come from a far countree. + +He kneels at morn, and noon, and eve— +He hath a cushion plump: +It is the moss that wholly hides +The rotted old oak-stump. + +The skiff-boat neared: I heard them talk, +'Why, this is strange, I trow! +Where are those lights so many and fair, +That signal made but now?' + +'Strange, by my faith!' the Hermit said— +'And they answered not our cheer! +The planks looked warped! and see those sails, +How thin they are and sere! +I never saw aught like to them, +Unless perchance it were + +Brown skeletons of leaves that lag +My forest-brook along; +When the ivy-tod is heavy with snow, +And the owlet whoops to the wolf below, +That eats the she-wolf's young.' + +'Dear Lord! it hath a fiendish look— +(The Pilot made reply) +I am a-feared'—'Push on, push on!' +Said the Hermit cheerily. + +The boat came closer to the ship, +But I nor spake nor stirred; +The boat came close beneath the ship, +And straight a sound was heard. + +Under the water it rumbled on, +Still louder and more dread: +It reached the ship, it split the bay; +The ship went down like lead. + +Stunned by that loud and dreadful sound, +Which sky and ocean smote, +Like one that hath been seven days drowned +My body lay afloat; +But swift as dreams, myself I found +Within the Pilot's boat. + +Upon the whirl, where sank the ship, +The boat spun round and round; +And all was still, save that the hill +Was telling of the sound. + +I moved my lips—the Pilot shrieked +And fell down in a fit; +The holy Hermit raised his eyes, +And prayed where he did sit. + +I took the oars: the Pilot's boy, +Who now doth crazy go, +Laughed loud and long, and all the while +His eyes went to and fro. +'Ha! ha!' quoth he, 'full plain I see, +The Devil knows how to row.' + +And now, all in my own countree, +I stood on the firm land! +The Hermit stepped forth from the boat, +And scarcely he could stand. + +'O shrieve me, shrieve me, holy man!' +The Hermit crossed his brow. +'Say quick,' quoth he, 'I bid thee say— +What manner of man art thou?' + +Forthwith this frame of mine was wrenched +With a woful agony, +Which forced me to begin my tale; +And then it left me free. + + +Since then, at an uncertain hour, +That agony returns: +And till my ghastly tale is told, +This heart within me burns. + +I pass, like night, from land to land; +I have strange power of speech; +That moment that his face I see, +I know the man that must hear me: +To him my tale I teach. + +What loud uproar bursts from that door! +The wedding-guests are there: +But in the garden-bower the bride +And bride-maids singing are: +And hark the little vesper bell, +Which biddeth me to prayer! + +O Wedding-Guest! this soul hath been +Alone on a wide wide sea: +So lonely 'twas, that God himself +Scarce seemèd there to be. + +O sweeter than the marriage-feast, +'Tis sweeter far to me, +To walk together to the kirk +With a goodly company!— + +To walk together to the kirk, +And all together pray, +While each to his great Father bends, +Old men, and babes, and loving friends +And youths and maidens gay! + +Farewell, farewell! but this I tell +To thee, thou Wedding-Guest! +He prayeth well, who loveth well +Both man and bird and beast. + +He prayeth best, who loveth best +All things both great and small; +For the dear God who loveth us, +He made and loveth all. + +The Mariner, whose eye is bright, +Whose beard with age is hoar, +Is gone: and now the Wedding-Guest +Turned from the bridegroom's door. + +He went like one that hath been stunned, +And is of sense forlorn: +A sadder and a wiser man, +He rose the morrow morn. ADDED src/0dev.org/commands/plaindiff/rime2.txt Index: src/0dev.org/commands/plaindiff/rime2.txt ================================================================== --- /dev/null +++ src/0dev.org/commands/plaindiff/rime2.txt @@ -0,0 +1,781 @@ +It is an ancient Mariner, +And he stoppeth one of three. +'By thy long grey beard and glittering eye, +Now wherefore stopp'st thou me? + +The Bridegroom's doors are opened wide, +And I am next of kin; +The guests are met, the feast is set: +May'st hear the merry din.' + +The Bridegroom's doors are opened wide, +And I am next of kin; +The guests are met, the feast is set: +May'st hear the merry din.' + + +He holds him with his skinny hand, +'There was a ship,' quoth he. +'Hold off! unhand me, grey-beard loon!' +Eftsoons his hand dropt he. + +He holds him with his glittering eye— +The Wedding-Guest stood still, +And listens like a three years' child: +The Mariner hath his will. + +The Wedding-Guest sat on a stone: +He cannot choose but hear; +And thus spake on that ancient man, +The bright-eyed Mariner. + +'The ship was cheered, the harbour cleared, +Merrily did we drop +Below the kirk, below the hill, +Below the lighthouse top. + +The Sun came up upon the left, +Out of the sea came he! +And he shone bright, and on the right +Went down into the sea. + +Higher and higher every day, +Till over the mast at noon—' +The Wedding-Guest here beat his breast, +For he heard the loud bassoon. + +The bride hath paced into the hall, +Red as a rose is she; +Nodding their heads before her goes +The merry minstrelsy. + +The Wedding-Guest he beat his breast, +Yet he cannot choose but hear; +And thus spake on that ancient man, +The bright-eyed Mariner. + +And now the STORM-BLAST came, and he +Was tyrannous and strong: +He struck with his o'ertaking wings, +And chased us south along. + +With sloping masts and dipping prow, +As who pursued with yell and blow +Still treads the shadow of his foe, +And forward bends his head, +The ship drove fast, loud roared the blast, +And southward aye we fled. + +And now there came both mist and snow, +And it grew wondrous cold: +And ice, mast-high, came floating by, +As green as emerald. + +And through the drifts the snowy clifts +Did send a dismal sheen: +Nor shapes of men nor beasts we ken— +The ice was all between. + +The ice was here, the ice was there, +The ice was all around: +It cracked and growled, and roared and howled, +Like noises in a swound! + +At length did cross an Albatross, +Thorough the fog it came; +As if it had been a Christian soul, +We hailed it in God's name. + +It ate the food it ne'er had eat, +And round and round it flew. +The ice did split with a thunder-fit; +The helmsman steered us through! + +And a good south wind sprung up behind; +The Albatross did follow, +And every day, for food or play, +Came to the mariner's hollo! + +In mist or cloud, on mast or shroud, +It perched for vespers nine; +Whiles all the night, through fog-smoke white, +Glimmered the white Moon-shine.' + +'God save thee, ancient Mariner! +From the fiends, that plague thee thus!— +Why look'st thou so?'—With my cross-bow +I shot the ALBATROSS. + +PART II +The Sun now rose upon the right: +Out of the sea came he, +Still hid in mist, and on the left +Went down into the sea. + +And the good south wind still blew behind, +But no sweet bird did follow, +Nor any day for food or play +Came to the mariner's hollo! + +And I had done a hellish thing, +And it would work 'em woe: +For all averred, I had killed the bird +That made the breeze to blow. +Ah wretch! said they, the bird to slay, +That made the breeze to blow! + +Nor dim nor red, like God's own head, +The glorious Sun uprist: +Then all averred, I had killed the bird +That brought the fog and mist. +'Twas right, said they, such birds to slay, +That bring the fog and mist. + +The fair breeze blew, the white foam flew, +The furrow followed free; +We were the first that ever burst +Into that silent sea. + +Down dropt the breeze, the sails dropt down, +'Twas sad as sad could be; +And we did speak only to break +The silence of the sea! + +All in a hot and copper sky, +The bloody Sun, at noon, +Right up above the mast did stand, +No bigger than the Moon. + +Day after day, day after day, +We stuck, nor breath nor motion; +As idle as a painted ship +Upon a painted ocean. + +Water, water, every where, +And all the boards did shrink; +Water, water, every where, +Nor any drop to drink. + +The very deep did rot: O Christ! +That ever this should be! +Yea, slimy things did crawl with legs +Upon the slimy sea. + +About, about, in reel and rout +The death-fires danced at night; +The water, like a witch's oils, +Burnt green, and blue and white. + +And some in dreams assurèd were +Of the Spirit that plagued us so; +Nine fathom deep he had followed us +From the land of mist and snow. + +And every tongue, through utter drought, +Was withered at the root; +We could not speak, no more than if +We had been choked with soot. + +Ah! well a-day! what evil looks +Had I from old and young! +Instead of the cross, the Albatross +About my neck was hung. + +PART III +There passed a weary time. Each throat +Was parched, and glazed each eye. +A weary time! a weary time! +How glazed each weary eye, + +When looking westward, I beheld +A something in the sky. + +At first it seemed a little speck, +And then it seemed a mist; +It moved and moved, and took at last +A certain shape, I wist. + +A speck, a mist, a shape, I wist! +And still it neared and neared: +As if it dodged a water-sprite, +It plunged and tacked and veered. + +With throats unslaked, with black lips baked, +We could nor laugh nor wail; +Through utter drought all dumb we stood! +I bit my arm, I sucked the blood, +And cried, A sail! a sail! + +With throats unslaked, with black lips baked, +Agape they heard me call: +Gramercy! they for joy did grin, +And all at once their breath drew in. +As they were drinking all. + +See! see! (I cried) she tacks no more! +Hither to work us weal; +Without a breeze, without a tide, +She steadies with upright keel! + +The western wave was all a-flame. +The day was well nigh done! +Almost upon the western wave +Rested the broad bright Sun; +When that strange shape drove suddenly +Betwixt us and the Sun. + +And straight the Sun was flecked with bars, +(Heaven's Mother send us grace!) +As if through a dungeon-grate he peered +With broad and burning face. + +Alas! (thought I, and my heart beat loud) +How fast she nears and nears! +Are those her sails that glance in the Sun, +Like restless gossameres? + +Are those her ribs through which the Sun +Did peer, as through a grate? +And is that Woman all her crew? +Is that a DEATH? and are there two? +Is DEATH that woman's mate? + +Her lips were red, her looks were free, +Her locks were yellow as gold: +Her skin was as white as leprosy, +The Night-mare LIFE-IN-DEATH was she, +Who thicks man's blood with cold. + +The naked hulk alongside came, +And the twain were casting dice; +'The game is done! I've won! I've won!' +Quoth she, and whistles thrice. + +The Sun's rim dips; the stars rush out; +At one stride comes the dark; +With far-heard whisper, o'er the sea, +Off shot the spectre-bark. + +One after one, by the star-dogged Moon, +Too quick for groan or sigh, +Each turned his face with a ghastly pang, +And cursed me with his eye. + +We listened and looked sideways up! +Fear at my heart, as at a cup, +My life-blood seemed to sip! +The stars were dim, and thick the night, +The steersman's face by his lamp gleamed white; +From the sails the dew did drip— +Till clomb above the eastern bar +The hornèd Moon, with one bright star +Within the nether tip. + +Four times fifty living men, +(And I heard nor sigh nor groan) +With heavy thump, a lifeless lump, +They dropped down one by one. + +The souls did from their bodies fly,— +They fled to bliss or woe! +And every soul, it passed me by, +Like the whizz of my cross-bow! + +PART IV +'I fear thee, ancient Mariner! +I fear thy skinny hand! +And thou art long, and lank, and brown, +As is the ribbed sea-sand. + +I fear thee and thy glittering eye, +And thy skinny hand, so brown.'— +Fear not, fear not, thou Wedding-Guest! +This body dropt not down. + +Alone, alone, all, all alone, +Alone on a wide wide sea! +And never a saint took pity on +My soul in agony. + +The many men, so beautiful! +And they all dead did lie: +And a thousand thousand slimy things +Lived on; and so did I. + +I looked upon the rotting sea, +And drew my eyes away; +I looked upon the rotting deck, +And there the dead men lay. + +I looked to heaven, and tried to pray; +But or ever a prayer had gusht, +A wicked whisper came, and made +My heart as dry as dust. + +I closed my lids, and kept them close, +And the balls like pulses beat; +For the sky and the sea, and the sea and the sky +Lay dead like a load on my weary eye, +And the dead were at my feet. + +The cold sweat melted from their limbs, +Nor rot nor reek did they: +The look with which they looked on me +Had never passed away. + +An orphan's curse would drag to hell +A spirit from on high; +But oh! more horrible than that +Is the curse in a dead man's eye! +Seven days, seven nights, I saw that curse, +And yet I could not die. + +The moving Moon went up the sky, +And no where did abide: +Softly she was going up, +And a star or two beside— + +Her beams bemocked the sultry main, +Like April hoar-frost spread; +But where the ship's huge shadow lay, +The charmèd water burnt alway +A still and awful red. + +Beyond the shadow of the ship, +I watched the water-snakes: +They moved in tracks of shining white, +And when they reared, the elfish light +Fell off in hoary flakes. + +Within the shadow of the ship +I watched their rich attire: +Blue, glossy green, and velvet black, +They coiled and swam; and every track +Was a flash of golden fire. + +O happy living things! no tongue +Their beauty might declare: +A spring of love gushed from my heart, +And I blessed them unaware: +Sure my kind saint took pity on me, +And I blessed them unaware. + +The self-same moment I could pray; +And from my neck so free +The Albatross fell off, and sank +Like lead into the sea. + +PART V +Oh sleep! it is a gentle thing, +Beloved from pole to pole! +To Mary Queen the praise be given! +She sent the gentle sleep from Heaven, +That slid into my soul. + +The silly buckets on the deck, +That had so long remained, +I dreamt that they were filled with dew; +And when I awoke, it rained. + +My lips were wet, my throat was cold, +My garments all were dank; +Sure I had drunken in my dreams, +And still my body drank. + +I moved, and could not feel my limbs: +I was so light—almost +I thought that I had died in sleep, +And was a blessed ghost. + +And soon I heard a roaring wind: +It did not come anear; +But with its sound it shook the sails, +That were so thin and sere. + +The upper air burst into life! +And a hundred fire-flags sheen, +To and fro they were hurried about! +And to and fro, and in and out, +The wan stars danced between. + +And the coming wind did roar more loud, +And the sails did sigh like sedge, +And the rain poured down from one black cloud; +The Moon was at its edge. + +The thick black cloud was cleft, and still +The Moon was at its side: +Like waters shot from some high crag, +The lightning fell with never a jag, +A river steep and wide. + +The loud wind never reached the ship, +Yet now the ship moved on! +Beneath the lightning and the Moon +The dead men gave a groan. + +They groaned, they stirred, they all uprose, +Nor spake, nor moved their eyes; +It had been strange, even in a dream, +To have seen those dead men rise. + +The helmsman steered, the ship moved on; +Yet never a breeze up-blew; +The mariners all 'gan work the ropes, +Where they were wont to do; +They raised their limbs like lifeless tools— +We were a ghastly crew. + +The body of my brother's son +Stood by me, knee to knee: +The body and I pulled at one rope, +But he said nought to me. + +'I fear thee, ancient Mariner!' +Be calm, thou Wedding-Guest! +'Twas not those souls that fled in pain, +Which to their corses came again, +But a troop of spirits blest: + +For when it dawned—they dropped their arms, +And clustered round the mast; +Sweet sounds rose slowly through their mouths, +And from their bodies passed. + +Around, around, flew each sweet sound, +Then darted to the Sun; +Slowly the sounds came back again, +Now mixed, now one by one. + +Sometimes a-dropping from the sky +I heard the sky-lark sing; +Sometimes all little birds that are, +How they seemed to fill the sea and air +With their sweet jargoning! + +And now 'twas like all instruments, +Now like a lonely flute; +And now it is an angel's song, +That makes the heavens be mute. + +It ceased; yet still the sails made on +A pleasant noise till noon, +A noise like of a hidden brook +In the leafy month of June, +That to the sleeping woods all night +Singeth a quiet tune. + +Till noon we quietly sailed on, +Yet never a breeze did breathe: +Slowly and smoothly went the ship, +Moved onward from beneath. + +Under the keel nine fathom deep, +From the land of mist and snow, +The spirit slid: and it was he +That made the ship to go. +The sails at noon left off their tune, +And the ship stood still also. + +The Sun, right up above the mast, +Had fixed her to the ocean: +But in a minute she 'gan stir, +With a short uneasy motion— +Backwards and forwards half her length +With a short uneasy motion. + +Then like a pawing horse let go, +She made a sudden bound: +It flung the blood into my head, +And I fell down in a swound. + +How long in that same fit I lay, +I have not to declare; +But ere my living life returned, +I heard and in my soul discerned +Two voices in the air. + +'Is it he?' quoth one, 'Is this the man? +By him who died on cross, +With his cruel bow he laid full low +The harmless Albatross. + +The spirit who bideth by himself +In the land of mist and snow, +He loved the bird that loved the man +Who shot him with his bow.' + +The other was a softer voice, +As soft as honey-dew: +Quoth he, 'The man hath penance done, +And penance more will do.' + +PART VI + +First Voice +'But tell me, tell me! speak again, +Thy soft response renewing— +What makes that ship drive on so fast? +What is the ocean doing?' + +Second Voice +Still as a slave before his lord, +The ocean hath no blast; +His great bright eye most silently +Up to the Moon is cast— + +If he may know which way to go; +For she guides him smooth or grim. +See, brother, see! how graciously +She looketh down on him.' + +First Voice +'But why drives on that ship so fast, +Without or wave or wind?' + +Second Voice +'The air is cut away before, +And closes from behind. + +Fly, brother, fly! more high, more high! +Or we shall be belated: +For slow and slow that ship will go, +When the Mariner's trance is abated.' + +I woke, and we were sailing on +As in a gentle weather: +'Twas night, calm night, the moon was high; +The dead men stood together. + +All stood together on the deck, +For a charnel-dungeon fitter: +All fixed on me their stony eyes, +That in the Moon did glitter. + +The pang, the curse, with which they died, +Had never passed away: +I could not draw my eyes from theirs, +Nor turn them up to pray. + +And now this spell was snapt: once more +I viewed the ocean green, +And looked far forth, yet little saw +Of what had else been seen— + +Like one, that on a lonesome road +Doth walk in fear and dread, +And having once turned round walks on, +And turns no more his head; +Because he knows, a frightful fiend +Doth close behind him tread. + +But soon there breathed a wind on me, +Nor sound nor motion made: +Its path was not upon the sea, +In ripple or in shade. + +It raised my hair, it fanned my cheek +Like a meadow-gale of spring— +It mingled strangely with my fears, +Yet it felt like a welcoming. + +Swiftly, swiftly flew the ship, +Yet she sailed softly too: +Sweetly, sweetly blew the breeze— +On me alone it blew. + +Oh! dream of joy! is this indeed +The light-house top I see? +Is this the hill? is this the kirk? +Is this mine own countree? + +We drifted o'er the harbour-bar, +And I with sobs did pray— +O let me be awake, my God! +Or let me sleep alway. + +The harbour-bay was clear as glass, +So smoothly it was strewn! +And on the bay the moonlight lay, +And the shadow of the Moon. + +The rock shone bright, the kirk no less, +That stands above the rock: +The moonlight steeped in silentness +The steady weathercock. + +And the bay was white with silent light, +Till rising from the same, +Full many shapes, that shadows were, +In crimson colours came. + +A little distance from the prow +Those crimson shadows were: +I turned my eyes upon the deck— +Oh, Christ! what saw I there! + +Each corse lay flat, lifeless and flat, +And, by the holy rood! +A man all light, a seraph-man, +On every corse there stood. + +This seraph-band, each waved his hand: +It was a heavenly sight! +They stood as signals to the land, +Each one a lovely light; + +This seraph-band, each waved his hand, +No voice did they impart— +No voice; but oh! the silence sank +Like music on my heart. + +But soon I heard the dash of oars, +I heard the Pilot's cheer; +My head was turned perforce away +And I saw a boat appear. + +The Pilot and the Pilot's boy, +I heard them coming fast: +Dear Lord in Heaven! it was a joy +The dead men could not blast. + +I saw a third—I heard his voice: +It is the Hermit good! +He singeth loud his godly hymns +That he makes in the wood. +He'll shrieve my soul, he'll wash away +The Albatross's blood. + +PART VII +This Hermit good lives in that wood +Which slopes down to the sea. +How loudly his sweet voice he rears! +He loves to talk with marineres +That come from a far countree. + +He kneels at morn, and noon, and eve— +He hath a cushion plump: +It is the moss that wholly hides +The rotted old oak-stump. + +The skiff-boat neared: I heard them talk, +'Why, this is strange, I trow! +Where are those lights so many and fair, +That signal made but now?' + +'Strange, by my faith!' the Hermit said— +'And they answered not our cheer! +The planks looked warped! and see those sails, +How thin they are and sere! +I never saw aught like to them, +Unless perchance it were + +Brown skeletons of leaves that lag +My forest-brook along; +When the ivy-tod is heavy with snow, +And the owlet whoops to the wolf below, +That eats the she-wolf's young.' + +'Dear Lord! it hath a fiendish look— +(The Pilot made reply) +I am a-feared'—'Push on, push on!' +Said the Hermit cheerily. + +The boat came closer to the ship, +But I nor spake nor stirred; +The boat came close beneath the ship, +And straight a sound was heard. + +Under the water it rumbled on, +Still louder and more dread: +It reached the ship, it split the bay; +The ship went down like lead. + +Stunned by that loud and dreadful sound, +Which sky and ocean smote, +Like one that hath been seven days drowned +My body lay afloat; +But swift as dreams, myself I found +Within the Pilot's boat. + +Upon the whirl, where sank the ship, +The boat spun round and round; +And all was still, save that the hill +Was telling of the sound. + +I moved my lips—the Pilot shrieked +And fell down in a fit; +The holy Hermit raised his eyes, +And prayed where he did sit. + +I took the oars: the Pilot's boy, +Who now doth crazy go, +Laughed loud and long, and all the while +His eyes went to and fro. +'Ha! ha!' quoth he, 'full plain I see, +The Devil knows how to row.' + +And now, all in my own countree, +I stood on the firm land! +The Hermit stepped forth from the boat, +And scarcely he could stand. + +'O shrieve me, shrieve me, holy man!' +The Hermit crossed his brow. +'Say quick,' quoth he, 'I bid thee say— +What manner of man art thou?' + +Forthwith this frame of mine was wrenched +With a woful agony, +Which forced me to begin my tale; +And then it left me free. + + +Since then, at an uncertain hour, +That agony returns: +And till my ghastly tale is told, +This heart within me burns. + +I pass, like night, from land to land; +I have strange power of speech; +That moment that his face I see, +I know the man that must hear me: +To him my tale I teach. + +What loud uproar bursts from that door! +The wedding-guests are there: +But in the garden-bower the bride +And bride-maids singing are: +And hark the little vesper bell, +Which biddeth me to prayer! + +O Wedding-Guest! this soul hath been +Alone on a wide wide sea: +So lonely 'twas, that God himself +Scarce seemèd there to be. + +O sweeter than the marriage-feast, +'Tis sweeter far to me, +To walk together to the kirk +With a goodly company!— + +To walk together to the kirk, +And all together pray, +While each to his great Father bends, +Old men, and babes, and loving friends +And youths and maidens gay! + +Farewell, farewell! but this I tell +To thee, thou Wedding-Guest! +He prayeth well, who loveth well +Both man and bird and beast. + +He prayeth best, who loveth best +All things both great and small; +For the dear God who loveth us, +He made and loveth all. + +He went like one that hath been stunned, +And is of sense forlorn: +A sadder and a wiser man, +He rose the morrow morn. ADDED src/0dev.org/diff/diff.go Index: src/0dev.org/diff/diff.go ================================================================== --- /dev/null +++ src/0dev.org/diff/diff.go @@ -0,0 +1,130 @@ +// Package diff provides a diff implementation +// for finite, indexable sequences with comparable elements +package diff + +import ( + bits "0dev.org/bits" +) + +// Interface abstracts the required knowledge to perform a diff +// on any two comparable, fixed-length sequences +type Interface interface { + // The sequences' lengths + Len() (int, int) + // True when the sequences' elements at those indices are equal + Equal(int, int) bool +} + +// A Mark struct marks a length in sequence starting with an offset +type Mark struct { + From int + Length int +} + +// A Delta struct is the result of a Diff operation +type Delta struct { + Added []Mark + Removed []Mark +} + +// Diffs the provided data and returns e Delta struct +// with added entries' indices in the second sequence and removed from the first +func Diff(data Interface) Delta { + var len1, len2 = data.Len() + var mat matrix = matrix{v: bits.New(uint(len1 * len2)), lenX: len1, lenY: len2} + + for i := 0; i < len1; i++ { + for j := 0; j < len2; j++ { + mat.v.Poke(mat.at(i, j), data.Equal(i, j)) + } + } + + return recursiveDiff(box{0, 0, len1, len2}, mat) +} + +type match struct { + x, y int + length int +} + +type box struct { + x, y int + lenX, lenY int +} + +// A helper structure that stores absolute dimension along a linear bit vector +// so that it can always properly translate (x, y) -> z on the vector +type matrix struct { + v bits.Vector + lenX, lenY int +} + +// Translates (x, y) to an absolute position on the bit vector +func (m *matrix) at(x, y int) uint { + return uint(y + (x * m.lenY)) +} + +func recursiveDiff(bounds box, mat matrix) Delta { + var m match = largest(bounds, mat) + + if m.length == 0 { // Recursion terminates + var immediate Delta + if bounds.lenY-bounds.y > 0 { + immediate.Added = []Mark{Mark{bounds.y, bounds.lenY}} + } + if bounds.lenX-bounds.x > 0 { + immediate.Removed = []Mark{Mark{bounds.x, bounds.lenX}} + } + return immediate + } + + var left Delta = recursiveDiff(box{bounds.x, bounds.y, m.x, m.y}, mat) + var right Delta = recursiveDiff(box{m.x + m.length, m.y + m.length, bounds.lenX, bounds.lenY}, mat) + + var result Delta + + result.Added = append(left.Added, right.Added...) + result.Removed = append(left.Removed, right.Removed...) + + return result +} + +// Finds the largest common substring by looking at the provided match matrix +// starting from (bounds.x, bounds.y) with lengths bounds.lenX, bounds.lenY +func largest(bounds box, mat matrix) (result match) { + for i := bounds.x; i < bounds.lenX; i++ { + var m match = search(i, bounds.y, bounds.lenX, bounds.lenY, mat) + if m.length > result.length { + result = m + } + } + for j := bounds.y + 1; j < bounds.lenY; j++ { + var m match = search(bounds.x, j, bounds.lenX, bounds.lenY, mat) + if m.length > result.length { + result = m + } + } + return +} + +// Searches the main diagonal for the longest sequential match line +func search(x, y, lenX, lenY int, mat matrix) (result match) { + var inMatch bool + var m match + for step := 0; step+x < lenX && step+y < lenY; step++ { + if mat.v.Peek(mat.at(step+x, step+y)) { + if !inMatch { // Create a new current record if there is none ... + inMatch, m.x, m.y, m.length = true, step+x, step+y, 1 + } else { // ... otherwise just increment the existing + m.length++ + } + + if m.length > result.length { + result = m // Store it if it is longer ... + } + } else { // End of current of match + inMatch = false // ... and reset the current one + } + } + return +} ADDED src/0dev.org/diff/diff_test.go Index: src/0dev.org/diff/diff_test.go ================================================================== --- /dev/null +++ src/0dev.org/diff/diff_test.go @@ -0,0 +1,72 @@ +package diff + +import ( + bits "0dev.org/bits" + "fmt" + "testing" +) + +type diffSlice struct { + first []rune + second []rune +} + +func (d diffSlice) Len() (int, int) { + return len(d.first), len(d.second) +} + +func (d diffSlice) Equal(i, j int) bool { + return d.first[i] == d.second[j] +} + +func TestLCS(t *testing.T) { + fmt.Println("") + + data := diffSlice{ + []rune("abcdefgh"), + []rune("abbcedfh"), + } + + fmt.Println(Diff(data)) + + // first, second, total := LCS(data) + // fmt.Println(first, second, total) +} + +func TestWTF(t *testing.T) { + data := diffSlice{ + []rune("abcdefgh"), + []rune("abbcedfh"), + } + + var len1, len2 int = data.Len() + var mat matrix = matrix{v: bits.NewBool(uint(len1 * len2)), lenX: len1, lenY: len2} + + for i := 0; i < len1; i++ { + for j := 0; j < len2; j++ { + mat.v.Poke(mat.at(i, j), data.Equal(i, j)) + } + } + + debugPrint(box{5, 5, 6, 6}, mat) + debugPrint(box{5, 5, 7, 7}, mat) + debugPrint(box{5, 5, 8, 8}, mat) +} + +func debugPrint(bounds box, mat matrix) { + // Debug print + fmt.Printf("-%d-%d--%d-%d--\n", bounds.x, bounds.y, bounds.lenX, bounds.lenY) + for i := bounds.x; i < bounds.lenX; i++ { + fmt.Print("| ") + for j := bounds.y; j < bounds.lenY; j++ { + //if vector.Peek(uint(j + (i * bounds.lenY))) { + if mat.v.Peek(mat.at(i, j)) { + fmt.Print("\\") + } else { + fmt.Print(".") + } + } + fmt.Println(" |") + } + fmt.Println("------------") +} ADDED src/0dev.org/math/math.go Index: src/0dev.org/math/math.go ================================================================== --- /dev/null +++ src/0dev.org/math/math.go @@ -0,0 +1,16 @@ +// Helper functions that really belong in the SDK or in a generic library... +package math + +func MinInt(i1, i2 int) int { + if i1 <= i2 { + return i1 + } + return i2 +} + +func MaxInt(i1, i2 int) int { + if i1 >= i2 { + return i1 + } + return i2 +}