Difference between revisions of "RawData"
Jump to navigation
Jump to search
m (added see-also) |
(→Examples: + Convert string -> RawData) |
||
| (3 intermediate revisions by 2 users not shown) | |||
| Line 56: | Line 56: | ||
| <c>[[RawData.utf8|utf8]](''self, offset=0, bytes=-1'')</c> || get a string of ASCII or UTF-8 text | | <c>[[RawData.utf8|utf8]](''self, offset=0, bytes=-1'')</c> || get a string of ASCII or UTF-8 text | ||
|- | |- | ||
| − | | <c>[[RawData.setUtf8|setUtf8]](''self, offset=0, value=""'')</c> || set a string as UTF-8 | + | | <c>[[RawData.setUtf8|setUtf8]](''self, offset=0, value=""'')</c> || set a string as UTF-8; return number of bytes written |
|} | |} | ||
| + | |||
| + | ==== Notes ==== | ||
| + | |||
| + | The getter and setter methods accept <c>offset</c> argument which, as with [[string]] and [[list]] indexing, may be <c>0 .. (len-1)</c> or <c>-len .. -1</c> where the negative indexes mean offset from the end of data. | ||
| + | |||
| + | If offset (positive or negative) is out of range, an <c>IndexError</c> is raised. Same error is raised if the span of read or written bytes go beyond the data boundaries, with the exception of <c>.setUtf8</c> that writes as much of its string value as possible and drops the rest. | ||
| + | |||
| + | === Examples === | ||
| + | |||
| + | <ms> | ||
| + | r = new RawData // Create new RawData of zero length | ||
| + | |||
| + | r.resize 100 // resize it before writing and reading data | ||
| + | |||
| + | r.setByte 42, 200 | ||
| + | |||
| + | print r.sbyte(42) // prints: -56 | ||
| + | </ms> | ||
| + | |||
| + | ==== Converting a string to RawData ==== | ||
| + | |||
| + | There's no easy way to know how big a string will be in bytes, but it should be less than (or equal to) 4 times the length. So start with a buffer equal to 4 times s.len, and then after you setUtf8 you can get the actual byte count, and resize your rawData down to size. | ||
| + | |||
| + | <ms> | ||
| + | r = new RawData | ||
| + | |||
| + | s = "ॐ मणि पद्मे हूँ" | ||
| + | |||
| + | r.resize s.len * 4 | ||
| + | |||
| + | r.resize r.setUtf8(0, s) | ||
| + | |||
| + | print r.utf8 == "ॐ मणि पद्मे हूँ" // prints: 1 | ||
| + | </ms> | ||
Latest revision as of 10:58, 15 May 2024
The RawData class in Mini Micro represents a buffer of raw bytes. Interpretation of these bytes is entirely up to the programmer.
See also: file.loadRaw, file.saveRaw
Properties
| Property Name | Type | Default Value | Meaning |
|---|---|---|---|
littleEndian |
number (boolean) | true | whether multi-byte values are stored with least significant byte first |
Methods
| Method | Description |
|---|---|
len |
returns the length of the raw data buffer, in bytes |
resize(bytes=32) |
change the size of the raw data buffer |
byte(self, offset=0) |
get one unsigned byte of data |
setByte(self, offset=0, value=0) |
set one unsigned byte value |
sbyte(self, offset=0) |
get one signed byte of data |
setSbyte(self, offset=0, value=0) |
set one signed byte value |
ushort(self, offset=0) |
get an unsigned 16-bit integer value |
setUshort(self, offset=0, value=0) |
set an unsigned 16-bit integer value |
short(self, offset=0) |
get a signed 16-bit integer value |
setShort(self, offset=0, value=0) |
set a signed 16-bit integer value |
uint(self, offset=0) |
get an unsigned 32-bit integer value |
setUint(self, offset=0, value=0) |
set an unsigned 32-bit integer value |
int(self, offset=0) |
get a signed 32-bit integer value |
setInt(self, offset=0, value=0) |
set a signed 32-bit integer value |
float(self, offset=0) |
get a 32-bit floating-point value |
setFloat(self, offset=0, value=0) |
set a 32-bit floating-point value |
double(self, offset=0) |
get a 64-bit floating-point value |
setDouble(self, offset=0, value=0) |
set a 64-bit floating-point value |
utf8(self, offset=0, bytes=-1) |
get a string of ASCII or UTF-8 text |
setUtf8(self, offset=0, value="") |
set a string as UTF-8; return number of bytes written |
Notes
The getter and setter methods accept offset argument which, as with string and list indexing, may be 0 .. (len-1) or -len .. -1 where the negative indexes mean offset from the end of data.
If offset (positive or negative) is out of range, an IndexError is raised. Same error is raised if the span of read or written bytes go beyond the data boundaries, with the exception of .setUtf8 that writes as much of its string value as possible and drops the rest.
Examples
r = new RawData // Create new RawData of zero length
r.resize 100 // resize it before writing and reading data
r.setByte 42, 200
print r.sbyte(42) // prints: -56
Converting a string to RawData
There's no easy way to know how big a string will be in bytes, but it should be less than (or equal to) 4 times the length. So start with a buffer equal to 4 times s.len, and then after you setUtf8 you can get the actual byte count, and resize your rawData down to size.
r = new RawData
s = "ॐ मणि पद्मे हूँ"
r.resize s.len * 4
r.resize r.setUtf8(0, s)
print r.utf8 == "ॐ मणि पद्मे हूँ" // prints: 1
