@lang:str.slice

Extract a section of a string.

On-chain (@lang:str.slice!): Slices bytes, so a multi-byte UTF-8 character may be cut in half.

Returns: string

Syntax

@lang:str.slice(value start end?)

Arguments

Name	Type	Description
value	string	Source string or bytes value
start	number	Start index (inclusive; negative counts from the end)
[end]	number	End index (exclusive; negative counts from the end; omitted = to the end)

See Also

• @str.at — access a single character
• @slice — array slice

On-chain face (@str.slice!)

Slice a byte range out of the string/bytes return of a call, on-chain. The range compiles to a single slice(data, start, len) read; negative indexes resolve against the live byte length at assertion time (-k compiles to sub(byteLen(s), k)).

Examples

load lang

set $pool 0x44fA8E6f47987339850636F88629646662444217

# First five bytes of the name
assert @str.slice!($pool::{name()(string)} 0 5) == "Curve"

# Last five bytes: the start resolves against the live length
assert @str.slice!($pool::{name()(string)} -5) == "Token"

Notes

• Indexes are BYTE offsets: multi-byte UTF-8 characters span several.
• There is no silent clamp on-chain: an out-of-range or inverted range reverts with SliceOutOfBounds at assertion time (constant inverted ranges fail at build time).
• String-valued: compare with ==/!=, or feed other string faces.

See Also

• assert, @str.at!, @str.split!