src/inflate.bend checks

raw source on the hub · import 0x57618559b9b26dd8415f821176a3e692/src/inflate.bend as Inflate

src/inflate: zlib-wrapped DEFLATE for a PNG IDAT stream (compression method 0). Blocks are stored, fixed Huffman, or dynamic Huffman.

1 import

import Base

Types

type Ph source · line 6 · raw

Data

where the bit reader is

PByte
```
Ph
```
PAlign
```
Ph
```
PSym
```
Ph
```
PDone
```
Ph
```
PFail
```
Ph
```

type Md source · line 14 · raw

Data

which integer the bit reader is filling

MCmf
```
Md
```
MFlg
```
Md
```
MBlk
```
Md
```
MLen
```
Md
```
MNlen
```
Md
```
MData
```
Md
```
MHlit
```
Md
```
MHdist
```
Md
```
MHclen
```
Md
```
MClen
```
Md
```
MXlen
```
Md
```
MXdist
```
Md
```
MAdler
```
Md
```
MRep
```
Md
```

type Wh source · line 31 · raw

Data

which Huffman table a symbol is read from

WLit
```
Wh
```
WDist
```
Wh
```
WClen
```
Wh
```

type St source · line 37 · raw

Data

one inflate reader: phase, tables, and the bytes emitted newest-first

St

@ph:Ph -> @md:Md -> @wh:Wh -> @+acc:U32 -> @+got:U32 -> @+need:U32 -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+hacc:U32 -> @+hlen:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

type lens.Split source · line 313 · raw

Data

the two halves of a code-length list

lens.Split

@lo:List<&2, U32> -> @hi:List<&2, U32> -> lens.Split

Definitions

def st.make source · line 43 · raw

@ph:Ph -> @md:Md -> @wh:Wh -> @+acc:U32 -> @+got:U32 -> @+need:U32 -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+hacc:U32 -> @+hlen:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

build a reader

def st.fail source · line 74 · raw

St

a reader that has failed

def st.empty source · line 78 · raw

St

the reader before the first byte

def st.gate source · line 82 · raw

@zz:Bool -> @aa:St -> @bb:St -> St

pick a reader

def huff.zeros source · line 93 · raw

@nn:Nat -> List<&2, U32>

sixteen zeros, or nineteen: a code-length histogram

def huff.at.put source · line 101 · raw

@+hh:U32 -> @+rest:U32 -> @zz:Bool -> U32

the value at an index, or zero past the end

def huff.at source · line 109 · raw

@xs:List<&2, U32> -> @+ii:U32 -> U32

the value at an index

def huff.set source · line 117 · raw

@xs:List<&2, U32> -> @zz:Bool -> @+ii:U32 -> @+vv:U32 -> List<&2, U32>

write an index. The Bool is "this is the slot".

def huff.bump source · line 127 · raw

@+acc:List<&2, U32> -> @+L:U32 -> @zz:Bool -> List<&2, U32>

count a nonzero length

def huff.count source · line 135 · raw

@ls:List<&2, U32> -> @acc:List<&2, U32> -> List<&2, U32>

bl_count, index is the length. Zeros are not counted.

def huff.next source · line 143 · raw

@counts:List<&2, U32> -> @+code:U32 -> @+prev:U32 -> @acc:List<&2, U32> -> List<&2, U32>

next_code, built newest-first

def huff.nexts source · line 152 · raw

@counts:List<&2, U32> -> List<&2, U32>

next_code[0] is zero, then one slot per length from 1

def huff.pack source · line 160 · raw

@+len:U32 -> @+code:U32 -> @+sym:U32 -> U32

pack length, canonical code, and symbol into one word

def huff.sym source · line 164 · raw

@+ee:U32 -> U32

the symbol in a packed entry

def huff.code source · line 168 · raw

@+ee:U32 -> U32

the code in a packed entry

def huff.len source · line 172 · raw

@+ee:U32 -> U32

the length in a packed entry

def huff.hit source · line 176 · raw

@+ee:U32 -> @+code:U32 -> @+len:U32 -> Bool

does this entry match the bits read so far?

def huff.find.put source · line 180 · raw

@+sym:U32 -> @rest:Maybe<&2, U32> -> @hit:Bool -> Maybe<&2, U32>

keep the symbol when the entry matches

def huff.find source · line 188 · raw

@tab:List<&2, U32> -> @+code:U32 -> @+len:U32 -> Maybe<&2, U32>

the symbol whose canonical code is these bits

def huff.keep source · line 196 · raw

@acc:List<&2, U32> -> @+sym:U32 -> @+len:U32 -> @+code:U32 -> @zz:Bool -> List<&2, U32>

cons a packed entry when the length is not zero

def huff.step source · line 204 · raw

@+nexts:List<&2, U32> -> @+len:U32 -> @zz:Bool -> List<&2, U32>

advance next_code at this length when it was used

def huff.assign source · line 212 · raw

@ls:List<&2, U32> -> @+sym:U32 -> @+nexts:List<&2, U32> -> @acc:List<&2, U32> -> List<&2, U32>

assign canonical codes in symbol order

def huff.canon source · line 221 · raw

@+ls:List<&2, U32> -> List<&2, U32>

canonical Huffman table from a length per symbol

def lit.len2 source · line 225 · raw

@cc:Bool -> U32

fixed literal/length code length at a symbol

def lit.len1 source · line 233 · raw

@bb:Bool -> @cc:Bool -> U32

fixed literal/length code length, past 143

def lit.len source · line 241 · raw

@+_s:U32 -> @aa:Bool -> @bb:Bool -> @cc:Bool -> U32

fixed literal/length code length

def lit.lens source · line 249 · raw

@ii:Nat -> @acc:List<&2, U32> -> List<&2, U32>

lengths 0..i, oldest first once i runs down to zero

def lit.fixed source · line 258 · raw

List<&2, U32>

the fixed literal/length table

def dist.lens source · line 262 · raw

@nn:Nat -> List<&2, U32>

thirty-two distance lengths of 5

def dist.fixed source · line 270 · raw

List<&2, U32>

the fixed distance table

def len.base source · line 274 · raw

List<&2, U32>

length bases for symbols 257..285

def len.extra source · line 278 · raw

List<&2, U32>

extra bits for symbols 257..285

def dist.base source · line 282 · raw

List<&2, U32>

distance bases

def dist.extra source · line 287 · raw

List<&2, U32>

extra bits for distances

def clen.order source · line 291 · raw

List<&2, U32>

code-length symbol order

def clen.place source · line 295 · raw

@order:List<&2, U32> -> @lens:List<&2, U32> -> @acc:List<&2, U32> -> List<&2, U32>

drop code-length values into the 19 symbol slots

def lens.rep source · line 305 · raw

@kk:Nat -> @+vv:U32 -> @lens:List<&2, U32> -> List<&2, U32>

repeat a length n times onto the front of the list

def lens.split source · line 317 · raw

@xs:List<&2, U32> -> @zz:Bool -> @+nn:U32 -> @acc:List<&2, U32> -> Maybe<&2, lens.Split>

split a list after n elements. The Bool is "n is zero".

def bits.push source · line 330 · raw

@ii:Nat -> @+bb:U32 -> @acc:List<&2, U32> -> List<&2, U32>

eight bits of a byte, low bit at the head

def bits.rows source · line 338 · raw

@xs:List<&2, U32> -> List<&2, List<&2, U32>>

one bit list per byte

def bits.of source · line 346 · raw

@xs:List<&2, U32> -> List<&2, U32>

the bit stream, low bit of each byte first

def adler.go source · line 350 · raw

@xs:List<&2, U32> -> @+aa:U32 -> @+bb:U32 -> Pair(U32, U32)

Adler-32, one byte at a time

def adler.fin source · line 360 · raw

@pp:Pair(U32, U32) -> U32

pack the two Adler sums

def adler.of source · line 366 · raw

@xs:List<&2, U32> -> U32

Adler-32 of chronological bytes

def copy.nth.put source · line 370 · raw

@+hh:U32 -> @rest:Maybe<&2, U32> -> @zz:Bool -> Maybe<&2, U32>

the byte i from the head

def copy.nth source · line 378 · raw

@xs:List<&2, U32> -> @+ii:U32 -> Maybe<&2, U32>

the byte i from the head, or none

def copy.run source · line 386 · raw

@nn:Nat -> @mm:Maybe<&2, U32> -> @+dist:U32 -> @+out:List<&2, U32> -> Maybe<&2, List<&2, U32>>

copy n bytes from dist back. m is the next byte, already read.

def copy.start source · line 397 · raw

@+len:U32 -> @+dist:U32 -> @+out:List<&2, U32> -> Maybe<&2, List<&2, U32>>

copy len bytes from dist back into a newest-first buffer

def rd.begin source · line 404 · raw

@md:Md -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

start the field md asks for, now that the stream is aligned

def rd.align source · line 436 · raw

@zz:Bool -> @md:Md -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

a byte-aligned field starts, or a padding bit is still waiting

def rd.to_align source · line 466 · raw

@md:Md -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

skip bits up to the next byte, then read md

def rd.byte source · line 491 · raw

@md:Md -> @wh:Wh -> @+need:U32 -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

a fresh integer field of need bits

def rd.after source · line 517 · raw

@final:Bool -> @wh:Wh -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

the next block, or the Adler checksum when this was the last block

def rd.sym source · line 546 · raw

@wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

literal/length or distance symbols

def rd.tree source · line 570 · raw

@wh:Wh -> @+lit:List<&2, U32> -> @+dts:List<&2, U32> -> @+clen:List<&2, U32> -> List<&2, U32>

the table a symbol is drawn from

def rd.cmf source · line 580 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

CMF: method 8, window at most 32K

def rd.flg source · line 605 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

FLG: the header check, and no preset dictionary

def rd.blk.dyn source · line 632 · raw

@final:Bool -> @z2:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

dynamic header, or a reserved block type

def rd.blk.huff source · line 658 · raw

@final:Bool -> @z1:Bool -> @z2:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

fixed or dynamic Huffman

def rd.blk.go source · line 685 · raw

@final:Bool -> @z0:Bool -> @z1:Bool -> @z2:Bool -> @wh:Wh -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

dispatch on the block type

def rd.blk.at source · line 716 · raw

@+finb:U32 -> @+bt:U32 -> @wh:Wh -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

BFINAL is the low bit. BTYPE is the next two.

def rd.blk source · line 741 · raw

@+val:U32 -> @wh:Wh -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

a stored block, a fixed block, or a dynamic block

def rd.len source · line 765 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

stored LEN, then NLEN

def rd.nlen.ok source · line 789 · raw

@zz:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

an empty stored block ends the block; otherwise the bytes follow

def rd.nlen source · line 818 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

NLEN is the one's complement of LEN

def rd.data.z source · line 843 · raw

@zz:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

one stored byte, newest-first

def rd.data source · line 877 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

consume one stored byte

def rd.hlit source · line 906 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

HLIT, then HDIST

def rd.hdist source · line 932 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

HDIST, then HCLEN

def rd.hclen source · line 958 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

HCLEN, then that many 3-bit code lengths

def rd.clen.z source · line 983 · raw

@zz:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @+lens:List<&2, U32> -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

code lengths are in. Build the code-length table and read the rest.

def rd.clen source · line 1017 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @lens:List<&2, U32> -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

one 3-bit code length

def rd.back source · line 1044 · raw

@_wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

literal/length symbols again, after a distance

def rd.copied source · line 1067 · raw

@mm:Maybe<&2, List<&2, U32>> -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

install the copied bytes, or fail

def rd.docopy source · line 1097 · raw

@wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @+out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

copy left bytes from dist back

def rd.xdist source · line 1123 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

extra distance bits are in dist as the base

def rd.xdist0 source · line 1150 · raw

@zz:Bool -> @+extra:U32 -> @+base:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

no extra distance bits: the base is the distance

def rd.distsym source · line 1185 · raw

@+sy:U32 -> @zz:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+rep:U32 -> St

a distance symbol

def rd.xlen source · line 1216 · raw

@+val:U32 -> @_wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

extra length bits added to the base kept in left

def rd.xlen0 source · line 1243 · raw

@zz:Bool -> @+extra:U32 -> @+base:U32 -> @wh:Wh -> @final:Bool -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

no extra length bits

def rd.lit.n source · line 1278 · raw

@zz:Bool -> @+sy:U32 -> @wh:Wh -> @final:Bool -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+rep:U32 -> St

a length symbol, or the end of the block

def rd.lit.e source · line 1310 · raw

@zend:Bool -> @zlen:Bool -> @+sy:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+rep:U32 -> St

end of block, or a length code

def rd.lit source · line 1345 · raw

@zlit:Bool -> @zend:Bool -> @zlen:Bool -> @+sy:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+rep:U32 -> St

a literal byte

def rd.finish.at source · line 1382 · raw

@mm:Maybe<&2, lens.Split> -> @_wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @clen:List<&2, U32> -> @+_nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

both Huffman tables are built

def rd.finish source · line 1410 · raw

@+lens:List<&2, U32> -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @clen:List<&2, U32> -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

split the length list into literal and distance tables

def rd.push source · line 1435 · raw

@zz:Bool -> @+prev:U32 -> @+nleft:U32 -> @lens:List<&2, U32> -> @wh:Wh -> @final:Bool -> @+left:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

a code length was stored. dist is 1 once any length exists.

def rd.rep16 source · line 1468 · raw

@zz:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+_rep:U32 -> St

code 16 needs a previous length

def rd.clen.t source · line 1499 · raw

@z18:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> St

code 18, or an illegal code-length symbol

def rd.clen.s source · line 1528 · raw

@z17:Bool -> @z18:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+_prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> St

codes 17 and 18 repeat zero

def rd.clen.r source · line 1562 · raw

@z16:Bool -> @z17:Bool -> @z18:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> St

repeat codes 16, 17, and 18

def rd.clens source · line 1597 · raw

@+sy:U32 -> @z15:Bool -> @z16:Bool -> @z17:Bool -> @z18:Bool -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+rep:U32 -> St

one code-length symbol

def rd.mrep.d source · line 1635 · raw

@zz:Bool -> @+lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

the repeat is done, or it ran past the list

def rd.mrep.z source · line 1669 · raw

@zbad:Bool -> @+nn:U32 -> @+prev:U32 -> @+nleft:U32 -> @lens:List<&2, U32> -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

reject a repeat that does not fit

def rd.mrep source · line 1703 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

extra bits of a repeat code

def rd.adler.eq source · line 1731 · raw

@zz:Bool -> @+raw:List<&2, U32> -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

Adler matches the bytes

def rd.adler.z source · line 1762 · raw

@zz:Bool -> @+run:U32 -> @+left:U32 -> @+out:List<&2, U32> -> @wh:Wh -> @final:Bool -> @+dist:U32 -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+sym:U32 -> @+rep:U32 -> St

one more Adler byte, or the check

def rd.adler source · line 1797 · raw

@+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @+out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

one big-endian Adler byte

def rd.field source · line 1826 · raw

@md:Md -> @+val:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

a finished integer field

def rd.raw.at source · line 1921 · raw

@zz:Bool -> @md:Md -> @wh:Wh -> @+acc:U32 -> @+got:U32 -> @+need:U32 -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

keep a partial integer, or dispatch it

def rd.raw source · line 1959 · raw

@md:Md -> @wh:Wh -> @+acc:U32 -> @+got:U32 -> @+need:U32 -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> @+bit:U32 -> St

fold one bit into the integer being read

def rd.miss source · line 1992 · raw

@zz:Bool -> @+code:U32 -> @+len:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

fifteen bits and no symbol is an error

def rd.symbol source · line 2025 · raw

@+sy:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+rep:U32 -> St

dispatch a decoded symbol

def rd.hbit.at source · line 2065 · raw

@found:Maybe<&2, U32> -> @+code:U32 -> @+len:U32 -> @wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> St

a symbol, or more bits

def rd.hbit source · line 2101 · raw

@+wh:Wh -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @+lit:List<&2, U32> -> @+dts:List<&2, U32> -> @+clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+hacc:U32 -> @+hlen:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> @+bit:U32 -> St

shift one Huffman bit in. The first bit is the high bit of the code.

def rd.on source · line 2133 · raw

@ph:Ph -> @md:Md -> @wh:Wh -> @+acc:U32 -> @+got:U32 -> @+need:U32 -> @final:Bool -> @+left:U32 -> @+dist:U32 -> @out:List<&2, U32> -> @lit:List<&2, U32> -> @dts:List<&2, U32> -> @clen:List<&2, U32> -> @lens:List<&2, U32> -> @+nleft:U32 -> @+prev:U32 -> @+cmf:U32 -> @+hacc:U32 -> @+hlen:U32 -> @+skew:U32 -> @+hlit:U32 -> @+hdist:U32 -> @+run:U32 -> @+sym:U32 -> @+rep:U32 -> @+bit:U32 -> St

one bit of the phase the reader is in

def rd.step source · line 2186 · raw

@st:St -> @+bit:U32 -> St

advance one bit. The bit count mod 8 tracks byte alignment.

def inflate.go source · line 2200 · raw

@bits:List<&2, U32> -> @st:St -> Maybe<&2, List<&2, U32>>

walk the bit list until the reader finishes or the bits run out

def inflate source · line 2218 · raw

@xs:List<&2, U32> -> Maybe<&2, List<&2, U32>>

inflate a zlib wrapper around DEFLATE, as PNG compression method 0