// Copyright 2023 The go-python Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

// Package array provides the implementation of the python's 'array' module.

package array

import (

"fmt"

"reflect"

"strings"

"github.com/go-python/gpython/py"

)

// FIXME(sbinet): consider creating an "array handler" type for each of the typecodes

// and make the handler a field of the "array" type.

// or make "array" an interface ?

// array provides efficient manipulation of C-arrays (as Go slices).

type array struct {

descr byte // typecode of elements

esize int // element size in bytes

data any

append func(v py.Object) (py.Object, error)

extend func(seq py.Object) (py.Object, error)

}

// Type of this StringDict object

func (*array) Type() *py.Type {

return ArrayType

}

var (

_ py.Object = (*array)(nil)

_ py.I__getitem__ = (*array)(nil)

_ py.I__setitem__ = (*array)(nil)

_ py.I__len__ = (*array)(nil)

_ py.I__repr__ = (*array)(nil)

_ py.I__str__ = (*array)(nil)

)

var (

typecodes = py.String("bBuhHiIlLqQfd")

ArrayType = py.ObjectType.NewType("array.array", array_doc, array_new, nil)

descr2esize = map[byte]int{

'b': 1,

'B': 1,

'u': 2,

'h': 2,

'H': 2,

'i': 2,

'I': 2,

'l': 8,

'L': 8,

'q': 8,

'Q': 8,

'f': 4,

'd': 8,

}

)

func init() {

py.RegisterModule(&py.ModuleImpl{

Info: py.ModuleInfo{

Name: "array",

Doc: "This module defines an object type which can efficiently represent\n" +

"an array of basic values: characters, integers, floating point\n" +

"numbers. Arrays are sequence types and behave very much like lists,\n" +

"except that the type of objects stored in them is constrained.\n",

},

Methods: []*py.Method{},

Globals: py.StringDict{

"typecodes": typecodes,

"array": ArrayType,

"ArrayType": ArrayType,

},

})

ArrayType.Dict["itemsize"] = &py.Property{

Fget: func(self py.Object) (py.Object, error) {

arr := self.(*array)

return py.Int(arr.esize), nil

},

Doc: "the size, in bytes, of one array item",

}

ArrayType.Dict["typecode"] = &py.Property{

Fget: func(self py.Object) (py.Object, error) {

arr := self.(*array)

return py.String(arr.descr), nil

},

Doc: "the typecode character used to create the array",

}

ArrayType.Dict["append"] = py.MustNewMethod("append", array_append, 0, array_append_doc)

ArrayType.Dict["extend"] = py.MustNewMethod("extend", array_extend, 0, array_extend_doc)

}

const array_doc = `array(typecode [, initializer]) -> array

Return a new array whose items are restricted by typecode, and

initialized from the optional initializer value, which must be a list,

string or iterable over elements of the appropriate type.

Arrays represent basic values and behave very much like lists, except

the type of objects stored in them is constrained. The type is specified

at object creation time by using a type code, which is a single character.

The following type codes are defined:

Type code C Type Minimum size in bytes

'b' signed integer 1

'B' unsigned integer 1

'u' Unicode character 2 (see note)

'h' signed integer 2

'H' unsigned integer 2

'i' signed integer 2

'I' unsigned integer 2

'l' signed integer 4

'L' unsigned integer 4

'q' signed integer 8 (see note)

'Q' unsigned integer 8 (see note)

'f' floating point 4

'd' floating point 8

NOTE: The 'u' typecode corresponds to Python's unicode character. On

narrow builds this is 2-bytes on wide builds this is 4-bytes.

NOTE: The 'q' and 'Q' type codes are only available if the platform

C compiler used to build Python supports 'long long', or, on Windows,

'__int64'.

Methods:

append() -- append a new item to the end of the array

buffer_info() -- return information giving the current memory info

byteswap() -- byteswap all the items of the array

count() -- return number of occurrences of an object

extend() -- extend array by appending multiple elements from an iterable

fromfile() -- read items from a file object

fromlist() -- append items from the list

frombytes() -- append items from the string

index() -- return index of first occurrence of an object

insert() -- insert a new item into the array at a provided position

pop() -- remove and return item (default last)

remove() -- remove first occurrence of an object

reverse() -- reverse the order of the items in the array

tofile() -- write all items to a file object

tolist() -- return the array converted to an ordinary list

tobytes() -- return the array converted to a string

Attributes:

typecode -- the typecode character used to create the array

itemsize -- the length in bytes of one array item

`

func array_new(metatype *py.Type, args py.Tuple, kwargs py.StringDict) (py.Object, error) {

switch n := len(args); n {

case 0:

return nil, py.ExceptionNewf(py.TypeError, "array() takes at least 1 argument (0 given)")

case 1, 2:

// ok

default:

return nil, py.ExceptionNewf(py.TypeError, "array() takes at most 2 arguments (%d given)", n)

}

if len(kwargs) != 0 {

return nil, py.ExceptionNewf(py.TypeError, "array.array() takes no keyword arguments")

}

descr, ok := args[0].(py.String)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "array() argument 1 must be a unicode character, not %s", args[0].Type().Name)

}

if len(descr) != 1 {

return nil, py.ExceptionNewf(py.TypeError, "array() argument 1 must be a unicode character, not str")

}

if !strings.ContainsAny(string(descr), string(typecodes)) {

ts := new(strings.Builder)

for i, v := range typecodes {

if i > 0 {

switch {

case i == len(typecodes)-1:

ts.WriteString(" or ")

default:

ts.WriteString(", ")

}

}

ts.WriteString(string(v))

}

return nil, py.ExceptionNewf(py.ValueError, "bad typecode (must be %s)", ts)

}

arr := &array{

descr: descr[0],

esize: descr2esize[descr[0]],

}

switch descr[0] {

case 'u':

var data []rune

arr.data = data

arr.append = arr.appendRune

arr.extend = arr.extendRune

case 'b':

var data []int8

arr.data = data

arr.append = arr.appendI8

arr.extend = arr.extendI8

case 'h':

var data []int16

arr.data = data

arr.append = arr.appendI16

arr.extend = arr.extendI16

case 'i':

var data []int32

arr.data = data

arr.append = arr.appendI32

arr.extend = arr.extendI32

case 'l', 'q':

var data []int64

arr.data = data

arr.append = arr.appendI64

arr.extend = arr.extendI64

case 'B':

var data []uint8

arr.data = data

arr.append = arr.appendU8

arr.extend = arr.extendU8

case 'H':

var data []uint16

arr.data = data

arr.append = arr.appendU16

arr.extend = arr.extendU16

case 'I':

var data []uint32

arr.data = data

arr.append = arr.appendU32

arr.extend = arr.extendU32

case 'L', 'Q':

var data []uint64

arr.data = data

arr.append = arr.appendU64

arr.extend = arr.extendU64

case 'f':

var data []float32

arr.data = data

arr.append = arr.appendF32

arr.extend = arr.extendF32

case 'd':

var data []float64

arr.data = data

arr.append = arr.appendF64

arr.extend = arr.extendF64

}

if len(args) == 2 {

_, err := arr.extend(args[1])

if err != nil {

return nil, err

}

}

return arr, nil

}

const array_append_doc = `Append new value v to the end of the array.`

func array_append(self py.Object, args py.Tuple) (py.Object, error) {

arr, ok := self.(*array)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "expected an array, got '%s'", self.Type().Name)

}

if len(args) != 1 {

return nil, py.ExceptionNewf(py.TypeError, "array.append() takes exactly one argument (%d given)", len(args))

}

return arr.append(args[0])

}

const array_extend_doc = `Append items to the end of the array.`

func array_extend(self py.Object, args py.Tuple) (py.Object, error) {

arr, ok := self.(*array)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "expected an array, got '%s'", self.Type().Name)

}

if len(args) == 0 {

return nil, py.ExceptionNewf(py.TypeError, "extend() takes exactly 1 positional argument (%d given)", len(args))

}

if len(args) != 1 {

return nil, py.ExceptionNewf(py.TypeError, "extend() takes at most 1 argument (%d given)", len(args))

}

return arr.extend(args[0])

}

func (arr *array) M__repr__() (py.Object, error) {

o := new(strings.Builder)

o.WriteString("array('" + string(arr.descr) + "'")

if data := reflect.ValueOf(arr.data); arr.data != nil && data.Len() > 0 {

switch arr.descr {

case 'u':

o.WriteString(", '")

o.WriteString(string(arr.data.([]rune)))

o.WriteString("'")

default:

o.WriteString(", [")

for i := 0; i < data.Len(); i++ {

if i > 0 {

o.WriteString(", ")

}

// FIXME(sbinet): we don't get exactly the same display wrt CPython for float32

fmt.Fprintf(o, "%v", data.Index(i))

}

o.WriteString("]")

}

}

o.WriteString(")")

return py.String(o.String()), nil

}

func (arr *array) M__str__() (py.Object, error) {

return arr.M__repr__()

}

func (arr *array) M__len__() (py.Object, error) {

if arr.data == nil {

return py.Int(0), nil

}

sli := reflect.ValueOf(arr.data)

return py.Int(sli.Len()), nil

}

func (arr *array) M__getitem__(k py.Object) (py.Object, error) {

switch k := k.(type) {

case py.Int:

var (

sli = reflect.ValueOf(arr.data)

i = int(k)

)

if i < 0 {

i = sli.Len() + i

}

if i < 0 || sli.Len() <= i {

return nil, py.ExceptionNewf(py.IndexError, "array index out of range")

}

switch arr.descr {

case 'b', 'h', 'i', 'l', 'q':

return py.Int(sli.Index(i).Int()), nil

case 'B', 'H', 'I', 'L', 'Q':

return py.Int(sli.Index(i).Uint()), nil

case 'u':

return py.String([]rune{rune(sli.Index(i).Int())}), nil

case 'f', 'd':

return py.Float(sli.Index(i).Float()), nil

}

case *py.Slice:

return nil, py.NotImplementedError

default:

return nil, py.ExceptionNewf(py.TypeError, "array indices must be integers")

}

panic("impossible")

}

func (arr *array) M__setitem__(k, v py.Object) (py.Object, error) {

switch k := k.(type) {

case py.Int:

var (

sli = reflect.ValueOf(arr.data)

i = int(k)

)

if i < 0 {

i = sli.Len() + i

}

if i < 0 || sli.Len() <= i {

return nil, py.ExceptionNewf(py.IndexError, "array index out of range")

}

switch arr.descr {

case 'b', 'h', 'i', 'l', 'q':

vv, ok := v.(py.Int)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "'%s' object cannot be interpreted as an integer", v.Type().Name)

}

sli.Index(i).SetInt(int64(vv))

case 'B', 'H', 'I', 'L', 'Q':

vv, ok := v.(py.Int)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "'%s' object cannot be interpreted as an integer", v.Type().Name)

}

sli.Index(i).SetUint(uint64(vv))

case 'u':

vv, ok := v.(py.Int)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "array item must be unicode character")

}

sli.Index(i).SetInt(int64(vv))

case 'f', 'd':

var vv float64

switch v := v.(type) {

case py.Int:

vv = float64(v)

case py.Float:

vv = float64(v)

default:

return nil, py.ExceptionNewf(py.TypeError, "must be real number, not %s", v.Type().Name)

}

sli.Index(i).SetFloat(vv)

}

return py.None, nil

case *py.Slice:

return nil, py.NotImplementedError

default:

return nil, py.ExceptionNewf(py.TypeError, "array indices must be integers")

}

panic("impossible")

}

func (arr *array) appendRune(v py.Object) (py.Object, error) {

str, ok := v.(py.String)

if !ok {

return nil, py.ExceptionNewf(py.TypeError, "array item must be unicode character")

}

arr.data = append(arr.data.([]rune), []rune(str)...)

return py.None, nil

}

func (arr *array) appendI8(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]int8), int8(vv))

return py.None, nil

}

func (arr *array) appendI16(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]int16), int16(vv))

return py.None, nil

}

func (arr *array) appendI32(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]int32), int32(vv))

return py.None, nil

}

func (arr *array) appendI64(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]int64), int64(vv))

return py.None, nil

}

func (arr *array) appendU8(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]uint8), uint8(vv))

return py.None, nil

}

func (arr *array) appendU16(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]uint16), uint16(vv))

return py.None, nil

}

func (arr *array) appendU32(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]uint32), uint32(vv))

return py.None, nil

}

func (arr *array) appendU64(v py.Object) (py.Object, error) {

vv, err := asInt(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]uint64), uint64(vv))

return py.None, nil

}

func (arr *array) appendF32(v py.Object) (py.Object, error) {

vv, err := py.FloatAsFloat64(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]float32), float32(vv))

return py.None, nil

}

func (arr *array) appendF64(v py.Object) (py.Object, error) {

vv, err := py.FloatAsFloat64(v)

if err != nil {

return nil, err

}

arr.data = append(arr.data.([]float64), float64(vv))

return py.None, nil

}

func (arr *array) extendRune(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendRune(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendI8(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendI8(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendI16(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendI16(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendI32(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendI32(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendI64(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendI64(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendU8(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendU8(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendU16(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendU16(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendU32(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendU32(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendU64(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendU64(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendF32(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendF32(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func (arr *array) extendF64(arg py.Object) (py.Object, error) {

itr, err := py.Iter(arg)

if err != nil {

return nil, err

}

nxt := itr.(py.I__next__)

for {

o, err := nxt.M__next__()

if err == py.StopIteration {

break

}

_, err = arr.appendF64(o)

if err != nil {

return nil, err

}

}

return py.None, nil

}

func asInt(o py.Object) (int64, error) {

v, ok := o.(py.Int)

if !ok {

return 0, py.ExceptionNewf(py.TypeError, "unsupported operand type(s) for int: '%s'", o.Type().Name)

}

return int64(v), nil

}