Mojo struct

StringSlice

A non-owning view to encoded string data.

Notes: TODO: The underlying string data is guaranteed to be encoded using UTF-8.

Parameters

is_mutable (Bool): Whether the slice is mutable.
origin (Origin[is_mutable.value]): The origin of the underlying string data.

Implemented traits

AnyType, CollectionElement, CollectionElementNew, Copyable, ExplicitlyCopyable, FloatableRaising, Hashable, IntableRaising, Movable, Sized, Stringable, Stringlike, Writable

Methods

`init`

__init__(out self: StringSlice[StaticConstantOrigin], lit: StringLiteral)

Construct a new StringSlice from a StringLiteral.

Args:

lit (StringLiteral): The literal to construct this StringSlice from.

__init__(out self, *, owned unsafe_from_utf8: Span[SIMD[uint8, 1], origin])

Construct a new StringSlice from a sequence of UTF-8 encoded bytes.

Safety: unsafe_from_utf8 MUST be valid UTF-8 encoded data.

Args:

unsafe_from_utf8 (Span[SIMD[uint8, 1], origin]): A Span[Byte] encoded in UTF-8.

__init__(out self, *, unsafe_from_utf8_strref: StringRef)

Construct a new StringSlice from a StringRef pointing to UTF-8 encoded bytes.

Safety: - unsafe_from_utf8_strref MUST point to data that is valid for origin. - unsafe_from_utf8_strref MUST be valid UTF-8 encoded data.

Args:

unsafe_from_utf8_strref (StringRef): A StringRef of bytes encoded in UTF-8.

__init__(out self, *, ptr: UnsafePointer[SIMD[uint8, 1]], length: Int)

Construct a StringSlice from a pointer to a sequence of UTF-8 encoded bytes and a length.

Safety: - ptr MUST point to at least length bytes of valid UTF-8 encoded data. - ptr must point to data that is live for the duration of origin.

Args:

ptr (UnsafePointer[SIMD[uint8, 1]]): A pointer to a sequence of bytes encoded in UTF-8.
length (Int): The number of bytes of encoded data.

__init__(out self, *, other: Self)

Explicitly construct a deep copy of the provided StringSlice.

Args:

other (Self): The StringSlice to copy.

__init__[O: ImmutableOrigin, //](out self: StringSlice[O], ref [O] value: String)

Construct an immutable StringSlice.

Parameters:

O (ImmutableOrigin): The immutable origin.

Args:

value (String): The string value.

`bool`

__bool__(self) -> Bool

Check if a string slice is non-empty.

Returns:

True if a string slice is non-empty, False otherwise.

`getitem`

__getitem__[IndexerType: Indexer](self, idx: IndexerType) -> String

Gets the character at the specified position.

Parameters:

IndexerType (Indexer): The inferred type of an indexer argument.

Args:

idx (IndexerType): The index value.

Returns:

A new string containing the character at the specified position.

`lt`

__lt__(self, rhs: StringSlice[origin]) -> Bool

Verify if the StringSlice bytes are strictly less than the input in overlapping content.

Args:

rhs (StringSlice[origin]): The other StringSlice to compare against.

Returns:

If the StringSlice bytes are strictly less than the input in overlapping content.

`eq`

__eq__(self, rhs: StringSlice[origin]) -> Bool

Verify if a StringSlice is equal to another StringSlice.

Args:

rhs (StringSlice[origin]): The StringSlice to compare against.

Returns:

If the StringSlice is equal to the input in length and contents.

__eq__(self, rhs: String) -> Bool

Verify if a StringSlice is equal to a string.

Args:

rhs (String): The String to compare against.

Returns:

If the StringSlice is equal to the input in length and contents.

__eq__(self, rhs: StringLiteral) -> Bool

Verify if a StringSlice is equal to a literal.

Args:

rhs (StringLiteral): The StringLiteral to compare against.

Returns:

If the StringSlice is equal to the input in length and contents.

`ne`

__ne__(self, rhs: StringSlice[origin]) -> Bool

Verify if span is not equal to another StringSlice.

Args:

rhs (StringSlice[origin]): The StringSlice to compare against.

Returns:

If the StringSlice is not equal to the input in length and contents.

__ne__(self, rhs: String) -> Bool

Verify if span is not equal to another StringSlice.

Args:

rhs (String): The StringSlice to compare against.

Returns:

If the StringSlice is not equal to the input in length and contents.

__ne__(self, rhs: StringLiteral) -> Bool

Verify if span is not equal to a StringLiteral.

Args:

rhs (StringLiteral): The StringLiteral to compare against.

Returns:

If the StringSlice is not equal to the input in length and contents.

`contains`

__contains__(ref self, substr: StringSlice[origin]) -> Bool

Returns True if the substring is contained within the current string.

Args:

substr (StringSlice[origin]): The substring to check.

Returns:

True if the string contains the substring.

`mul`

__mul__(self, n: Int) -> String

Concatenates the string n times.

Args:

n (Int): The number of times to concatenate the string.

Returns:

The string concatenated n times.

`str`

__str__(self) -> String

Gets this slice as a standard String.

Returns:

The string representation of the slice.

`len`

__len__(self) -> Int

Nominally returns the length in Unicode codepoints (not bytes!).

Returns:

The length in Unicode codepoints.

`write_to`

write_to[W: Writer](self, inout writer: W)

Formats this string slice to the provided Writer.

Parameters:

W (Writer): A type conforming to the Writable trait.

Args:

writer (W): The object to write to.

`hash`

__hash__(self) -> UInt

Hash the underlying buffer using builtin hash.

Returns:

A 64-bit hash value. This value is not suitable for cryptographic uses. Its intended usage is for data structures. See the hash builtin documentation for more details.

`iter`

__iter__(self) -> _StringSliceIter[origin]

Iterate over the string, returning immutable references.

Returns:

An iterator of references to the string elements.

`reversed`

__reversed__(self) -> _StringSliceIter[origin, 0]

Iterate backwards over the string, returning immutable references.

Returns:

A reversed iterator of references to the string elements.

`int`

__int__(self) -> Int

Parses the given string as a base-10 integer and returns that value. If the string cannot be parsed as an int, an error is raised.

Returns:

An integer value that represents the string, or otherwise raises.

`float`

__float__(self) -> SIMD[float64, 1]

Parses the string as a float point number and returns that value. If the string cannot be parsed as a float, an error is raised.

Returns:

A float value that represents the string, or otherwise raises.

`strip`

strip(self) -> Self

Gets a StringRef with leading and trailing whitespaces removed. This only takes ASCII whitespace into account: " \t\n\v\f\r\x1c\x1d\x1e".

Examples:

print("  mojo  ".strip()) # "mojo"
print("  mojo  ".strip()) # "mojo"

Returns:

A StringRef with leading and trailing whitespaces removed.

`as_bytes`

as_bytes(self) -> Span[SIMD[uint8, 1], origin]

Get the sequence of encoded bytes of the underlying string.

Returns:

A slice containing the underlying sequence of encoded bytes.

`unsafe_ptr`

unsafe_ptr(self) -> UnsafePointer[SIMD[uint8, 1]]

Gets a pointer to the first element of this string slice.

Returns:

A pointer pointing at the first element of this string slice.

`byte_length`

byte_length(self) -> Int

Get the length of this string slice in bytes.

Returns:

The length of this string slice in bytes.

`startswith`

startswith(self, prefix: StringSlice[origin], start: Int = 0, end: Int = -1) -> Bool

Verify if the StringSlice starts with the specified prefix between start and end positions.

Args:

prefix (StringSlice[origin]): The prefix to check.
start (Int): The start offset from which to check.
end (Int): The end offset from which to check.

Returns:

True if the self[start:end] is prefixed by the input prefix.

`endswith`

endswith(self, suffix: StringSlice[origin], start: Int = 0, end: Int = -1) -> Bool

Verify if the StringSlice end with the specified suffix between start and end positions.

Args:

suffix (StringSlice[origin]): The suffix to check.
start (Int): The start offset from which to check.
end (Int): The end offset from which to check.

Returns:

True if the self[start:end] is suffixed by the input suffix.

`format`

format[*Ts: _CurlyEntryFormattable](self, *args: *Ts) -> String

Format a template with *args.

Examples:

# Manual indexing:
print("{0} {1} {0}".format("Mojo", 1.125)) # Mojo 1.125 Mojo
# Automatic indexing:
print("{} {}".format(True, "hello world")) # True hello world
# Manual indexing:
print("{0} {1} {0}".format("Mojo", 1.125)) # Mojo 1.125 Mojo
# Automatic indexing:
print("{} {}".format(True, "hello world")) # True hello world

Parameters:

*Ts (_CurlyEntryFormattable): The types of substitution values that implement Representable and Stringable (to be changed and made more flexible).

Args:

*args (*Ts): The substitution values.

Returns:

The template with the given values substituted.

`find`

find(ref self, substr: StringSlice[origin], start: Int = 0) -> Int

Finds the offset of the first occurrence of substr starting at start. If not found, returns -1.

Args:

substr (StringSlice[origin]): The substring to find.
start (Int): The offset from which to find.

Returns:

The offset of substr relative to the beginning of the string.

`rfind`

rfind(self, substr: StringSlice[origin], start: Int = 0) -> Int

Finds the offset of the last occurrence of substr starting at start. If not found, returns -1.

Args:

substr (StringSlice[origin]): The substring to find.
start (Int): The offset from which to find.

Returns:

The offset of substr relative to the beginning of the string.

`isspace`

isspace(self) -> Bool

Determines whether every character in the given StringSlice is a python whitespace String. This corresponds to Python's universal separators: " \t\n\v\f\r\x1c\x1d\x1e\x85\u2028\u2029".

Returns:

True if the whole StringSlice is made up of whitespace characters listed above, otherwise False.

`isnewline`

isnewline[single_character: Bool = 0](self) -> Bool

Determines whether every character in the given StringSlice is a python newline character. This corresponds to Python's universal newlines: "\r\n" and "\t\n\v\f\r\x1c\x1d\x1e\x85\u2028\u2029".

Parameters:

single_character (Bool): Whether to evaluate the stringslice as a single unicode character (avoids overhead when already iterating).

Returns:

True if the whole StringSlice is made up of whitespace characters listed above, otherwise False.

`splitlines`

splitlines[O: ImmutableOrigin, //](self: StringSlice[O], keepends: Bool = 0) -> List[StringSlice[$0]]

Split the string at line boundaries. This corresponds to Python's universal newlines: "\r\n" and "\t\n\v\f\r\x1c\x1d\x1e\x85\u2028\u2029".

Parameters:

O (ImmutableOrigin): The immutable origin.

Args:

keepends (Bool): If True, line breaks are kept in the resulting strings.

Returns:

A List of Strings containing the input split by line boundaries.

Parameters​

Implemented traits​

Methods​

__init__​

__bool__​

__getitem__​

__lt__​

__eq__​

__ne__​

__contains__​

__mul__​

__str__​

__len__​

write_to​

__hash__​

__iter__​

__reversed__​

__int__​

__float__​

strip​

as_bytes​

unsafe_ptr​

byte_length​

startswith​

endswith​

format​

find​

rfind​

isspace​

isnewline​

splitlines​

Parameters

Implemented traits

Methods

`init`

`bool`

`getitem`

`lt`

`eq`

`ne`

`contains`

`mul`

`str`

`len`

`write_to`

`hash`

`iter`

`reversed`

`int`

`float`

`strip`

`as_bytes`

`unsafe_ptr`

`byte_length`

`startswith`

`endswith`

`format`

`find`

`rfind`

`isspace`

`isnewline`

`splitlines`