45 lines
1.8 KiB
BQN
45 lines
1.8 KiB
BQN
⟨SaveNpy,LoadNpy⟩⇐
|
||
|
||
lf←@+10
|
||
magicString←(@+147)∾"NUMPY"
|
||
|
||
# Type conversions
|
||
dtypes‿formats←⟨"<f8","<i4","<u4"⟩‿⟨64‿'f',32‿'i',32‿'u'⟩
|
||
DtypeToFormat←{(⊑dtypes⊐<𝕩)⊑formats}
|
||
ArrayToBytes←{⟨DtypeToFormat 𝕨,8‿'c'⟩•bit._cast 𝕩}
|
||
ArrayFromBytes←{⟨8‿'c',DtypeToFormat 𝕨⟩•bit._cast 𝕩}
|
||
|
||
# Saving
|
||
To_i16le←{@+256(|∾⌊∘÷˜)𝕩}
|
||
FormatShape←{'('∾(1↓∾⥊','∾˘•Fmt¨≢𝕩)∾')'}
|
||
|
||
BuildHeader←{dtype 𝕊 data:
|
||
version←1‿0
|
||
# Hypothesis: BQN arrays are C-contiguous
|
||
headerData←"{'descr':'"∾dtype∾"','fortran_order':False,'shape':"∾(FormatShape data)∾",}"
|
||
padding←' '↑˜64-64|(≠magicString)+2+2+(≠headerData)+1
|
||
! 0=64|(≠magicString)+2+2+(≠padding)+(≠headerData)+1
|
||
headerDataPadded←headerData∾padding∾lf
|
||
magicString∾(@+version)∾(To_i16le ≠headerDataPadded)∾headerDataPadded
|
||
}
|
||
DetectDtype←{(∧´⥊⌊⊸=¨𝕩)⊑⟨"<f8",(∧´⥊0≤𝕩)⊑"<i4"‿"<u4"⟩}
|
||
EncodeNpy←DetectDtype⊸(BuildHeader∾ArrayToBytes⟜⥊)
|
||
SaveNpy←•file.Bytes⟜EncodeNpy
|
||
|
||
# Loading
|
||
ParseHeader←{𝕊𝕩:
|
||
"Not a valid NPY file"! magicString≡(≠magicString)↑𝕩
|
||
version←@-˜(0‿1+≠magicString)⊏𝕩
|
||
headerlen←+´1‿256×@-˜(2‿3+≠magicString)⊏𝕩
|
||
header←(¬∊⟜(' '∾lf))⊸/headerlen↑(4+≠magicString)↓𝕩
|
||
dtype←3↑(⊐⟜'<'↓⊢) (("descr"⍷header)⊐1)↓header
|
||
shapestr←(⊐⟜')'↑⊢) (1⊸+∘⊐⟜'('↓⊢) (("shape"⍷header)⊐1)↓header
|
||
shape←•BQN¨','((⊢-˜+`׬)∘=⊔⊢)shapestr
|
||
⟨version,dtype,shape,headerlen+2+2+≠magicString⟩
|
||
}
|
||
|
||
LoadNpy←{𝕊𝕩:
|
||
bytes←•file.Bytes 𝕩
|
||
version‿dtype‿shape‿datastart←ParseHeader bytes
|
||
shape⥊dtype ArrayFromBytes datastart↓bytes
|
||
}
|