Mojo struct
StringRef
Represent a constant reference to a string, i.e. a sequence of characters and a length, which need not be null terminated.
Fields
- data (
UnsafePointer[SIMD[uint8, 1]]): A pointer to the beginning of the string data being referenced. - length (
Int): The length of the string being referenced.
Implemented traits
AnyType,
AsBytes,
Boolable,
CollectionElement,
CollectionElementNew,
Comparable,
Copyable,
EqualityComparable,
ExplicitlyCopyable,
Hashable,
IntableRaising,
Movable,
Representable,
Sized,
Stringable,
Writable,
_HashableWithHasher
Methods
__init__
__init__(out self)
Construct a StringRef value with length zero.
__init__(out self, *, other: Self)
Copy the object.
Args:
- other (
Self): The value to copy.
__init__(out self, str: StringLiteral)
Construct a StringRef value given a constant string.
Args:
- str (
StringLiteral): The input constant string.
__init__(out self, ptr: UnsafePointer[SIMD[int8, 1]], len: Int)
Construct a StringRef value given a (potentially non-0 terminated string).
The constructor takes a raw pointer and a length.
Note that you should use the constructor from UnsafePointer[UInt8] instead
as we are now storing the bytes as UInt8.
See https://github.com/modularml/mojo/issues/2317 for more information.
Args:
- ptr (
UnsafePointer[SIMD[int8, 1]]): UnsafePointer to the string. - len (
Int): The length of the string.
__init__(out self, *, ptr: UnsafePointer[SIMD[uint8, 1]])
Construct a StringRef value given a null-terminated string.
Args:
- ptr (
UnsafePointer[SIMD[uint8, 1]]): UnsafePointer to the string.
__init__(out self, ptr: UnsafePointer[SIMD[int8, 1]])
Construct a StringRef value given a null-terminated string.
Note that you should use the constructor from UnsafePointer[UInt8] instead
as we are now storing the bytes as UInt8.
See https://github.com/modularml/mojo/issues/2317 for more information.
Args:
- ptr (
UnsafePointer[SIMD[int8, 1]]): UnsafePointer to the string.
__bool__
__bool__(self) -> Bool
Checks if the string is empty or not.
Returns:
Returns True if the string is not empty and False otherwise.
__getitem__
__getitem__(self, idx: Int) -> Self
Get the string value at the specified position.
Args:
- idx (
Int): The index position.
Returns:
The character at the specified position.
__lt__
__lt__(self, rhs: Self) -> Bool
Compare this StringRef to the RHS using LT comparison.
Args:
- rhs (
Self): The other StringRef to compare against.
Returns:
True if this string is strictly less than the RHS string and False otherwise.
__le__
__le__(self, rhs: Self) -> Bool
Compare this StringRef to the RHS using LE comparison.
Args:
- rhs (
Self): The other StringRef to compare against.
Returns:
True if this string is less than or equal to the RHS string and False otherwise.
__eq__
__eq__(self, rhs: Self) -> Bool
Compares two strings are equal.
Args:
- rhs (
Self): The other string.
Returns:
True if the strings match and False otherwise.
__ne__
__ne__(self, rhs: Self) -> Bool
Compares two strings are not equal.
Args:
- rhs (
Self): The other string.
Returns:
True if the strings do not match and False otherwise.
__gt__
__gt__(self, rhs: Self) -> Bool
Compare this StringRef to the RHS using GT comparison.
Args:
- rhs (
Self): The other StringRef to compare against.
Returns:
True if this string is strictly greater than the RHS string and False otherwise.
__ge__
__ge__(self, rhs: Self) -> Bool
Compare this StringRef to the RHS using GE comparison.
Args:
- rhs (
Self): The other StringRef to compare against.
Returns:
True if this string is greater than or equal to the RHS string and False otherwise.
__contains__
__contains__(self, substr: Self) -> Bool
Returns True if the substring is contained within the current string.
Args:
- substr (
Self): The substring to check.
Returns:
True if the string contains the substring.
take_front
take_front(self, num_bytes: Int = 1) -> Self
Return a StringRef equal to 'self' but with only the first num_bytes elements remaining. If num_bytes is greater than the length of the string, the entire string is returned.
Args:
- num_bytes (
Int): The number of bytes to include.
Returns:
A new slice that starts with those bytes.
take_back
take_back(self, num_bytes: Int = 1) -> Self
Return a StringRef equal to 'self' but with only the last num_bytes elements remaining. If num_bytes is greater than the length of the string, the entire string is returned.
Args:
- num_bytes (
Int): The number of bytes to include.
Returns:
A new slice that ends with those bytes.
drop_front
drop_front(self, num_bytes: Int = 1) -> Self
Return a StringRef equal to 'self' but with the first num_bytes elements skipped. If num_bytes is greater than the length of the string, an empty StringRef is returned.
Args:
- num_bytes (
Int): The number of bytes to drop.
Returns:
A new slice with those bytes skipped.
drop_back
drop_back(self, num_bytes: Int = 1) -> Self
Return a StringRef equal to 'self' but with the last num_bytes elements skipped. If num_bytes is greater than the length of the string, the entire string is returned.
Args:
- num_bytes (
Int): The number of bytes to include.
Returns:
A new slice ends earlier than those bytes.
as_bytes
as_bytes(ref self) -> Span[SIMD[uint8, 1], $1]
Returns a contiguous Span of the bytes owned by this string.
Returns:
A contiguous slice pointing to the bytes owned by this string.
__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.
__hash__[H: _Hasher](self, inout hasher: H)
Updates hasher with the underlying bytes.
Parameters:
- H (
_Hasher): The hasher type.
Args:
- hasher (
H): The hasher instance.
__int__
__int__(self) -> Int
Parses the given string as a base-10 integer and returns that value.
For example, int("19") returns 19. If the given string cannot be parsed
as an integer value, an error is raised. For example, int("hi") raises an
error.
Returns:
An integer value that represents the string, or otherwise raises.
__len__
__len__(self) -> Int
Returns the length of the string.
Returns:
The length of the string.
__str__
__str__(self) -> String
Convert the string reference to a string.
Returns:
A new string.
__repr__
__repr__(self) -> String
Convert the string reference to a string.
Returns:
The String representation of the StringRef.
write_to
write_to[W: Writer](self, inout writer: W)
Formats this StringRef to the provided Writer.
Parameters:
- W (
Writer): A type conforming to the Writable trait.
Args:
- writer (
W): The object to write to.
__fspath__
__fspath__(self) -> String
Return the file system path representation of the object.
Returns:
The file system path representation as a string.
unsafe_ptr
unsafe_ptr(self) -> UnsafePointer[SIMD[uint8, 1]]
Retrieves a pointer to the underlying memory.
Returns:
The pointer to the underlying memory.
empty
empty(self) -> Bool
Returns True if the StringRef has length = 0.
Returns:
Whether the stringref is empty.
count
count(self, substr: Self) -> Int
Return the number of non-overlapping occurrences of substring substr in the string.
If sub is empty, returns the number of empty strings between characters which is the length of the string plus one.
Args:
- substr (
Self): The substring to count.
Returns:
The number of occurrences of substr.
find
find(self, substr: Self, start: Int = 0) -> Int
Finds the offset of the first occurrence of substr starting at start. If not found, returns -1.
Args:
- substr (
Self): 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: Self, start: Int = 0) -> Int
Finds the offset of the last occurrence of substr starting at start. If not found, returns -1.
Args:
- substr (
Self): The substring to find. - start (
Int): The offset from which to find.
Returns:
The offset of substr relative to the beginning of the string.
strip
strip(self) -> Self
Gets a StringRef with leading and trailing whitespaces removed. This only takes C spaces into account: " \t\n\v\f\r".
For example, " mojo " returns "mojo".
Returns:
A StringRef with leading and trailing whitespaces removed.
split
split(self, delimiter: Self) -> List[StringRef]
Split the StringRef by a delimiter.
Args:
- delimiter (
Self): The StringRef to split on.
Returns:
A List of StringRefs containing the input split by the delimiter.
Raises:
Error if an empty delimiter is specified.
startswith
startswith(self, prefix: Self, start: Int = 0, end: Int = -1) -> Bool
Checks if the StringRef starts with the specified prefix between start and end positions. Returns True if found and False otherwise.
Args:
- prefix (
Self): 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: Self, start: Int = 0, end: Int = -1) -> Bool
Checks if the StringRef end with the specified suffix between start and end positions. Returns True if found and False otherwise.
Args:
- suffix (
Self): 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.
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