string.c File Reference

#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <htils/arena.h>
#include <htils/assert.h>
#include <htils/basictypes.h>
#include <htils/darray.h>

Functions
static b32	is_whitespace (u8 c)
	Whether a byte is ASCII whitespace.
string *	string_new (arena_t *arena, const u64 len)
	Creates a new string.
string *	string_from_cstr (arena_t *arena, const cstr *base)
	Create a string from a C-string.
string_slice	string_slice_from_cstr (u8 *base, u64 len)
	Create a string_slice from a C-string.
string_slice	string_slice_from_string (string *str)
	Create a string_slice from a string.
cstr *	string_to_cstr (const string *str)
	Convert a string to a cstr.
string *	string_dup (arena_t *arena, const string *from)
	Duplicates from to a new string.
u64	string_concat (arena_t *arena, string *dest, const string *src)
	Concatenates two string.
u64	string_concatb (arena_t *arena, string *dest, const string *src, const u64 len)
	Concatenate len bytes of src to dest.
u64	string_concatf (arena_t *arena, string *dest, const cstr *fmt,...)
	Concatenates a formatted cstr to a string.
b32	stringcmp (const string *first, const string *second)
	Compare two string.
b32	stringcmpb (const string *first, const string *second, const u64 len)
	Compares len bytes of each string.
u64	string_split (string *src, u8 delim, string ***darray, arena_t *arena)
	Splits a string by a delimiter.
void	string_trim (string *str)
	Trims whitespace from the start and end of a string.
void	string_trim_left (string *str)
	Trims whitespace from the start of a string.
void	string_trim_right (string *str)
	Trims whitespace from the end of a string.
i64	string_findc (string *haystack, u8 needle)
	Finds the first occurence of a character in a string.
i64	string_find_sstr (string *haystack, string *needle)
	Finds the first occurance of a string in a string.

Function Documentation

is_whitespace()

b32 is_whitespace ( u8 c )

inlinestatic

Whether a byte is ASCII whitespace.

Parameters

c	The byte to test.

Returns

true for space, tab, CR, or LF.

string_concat()

u64 string_concat	(	arena_t *	arena,
		string *	dest,
		const string *	src )

Concatenates two string.

Allocates a buffer for the whole of dest plus src, copies both in, and updates dest in place to point at it. The previous buffer is left to the arena.

Parameters

arena	The arena to allocate the new string in.
dest	The string to set to the new string.
src	The string to concatenate to the dest string.

Precondition

arena, dest, and src must be valid and cannot be null.

Returns

The length of the new string for verification purposes.

See also

string, arena, arena_alloc()

string_concatb()

u64 string_concatb	(	arena_t *	arena,
		string *	dest,
		const string *	src,
		const u64	len )

Concatenate len bytes of src to dest.

Like string_concat(), but appends only the first len bytes of src.

Parameters

arena	The arena to allocate the new string in.
dest	The string to set to the new string.
src	The string to concatenate to the dest string.
len	The length of the bytes to concatenate.

Precondition

• arena, dest, and src must be valid and cannot be null.
• len must be greater than 0.

Returns

The length of the new string for verification purposes.

See also

string, arena, arena_alloc()

string_concatf()

u64 string_concatf	(	arena_t *	arena,
		string *	dest,
		const cstr *	fmt,
			... )

Concatenates a formatted cstr to a string.

Formats fmt with the variadic arguments, then appends the result to dest.

Parameters

arena	The arena to allocate the new string in.
dest	The string to set to the new string.
fmt	The format cstr to concatenate to the dest string.
...	The variadic args to format the string with.

Precondition

arena, dest, and fmt must be valid and cannot be null.

Returns

The length of the new string for verification purposes.

See also

string, arena, arena_alloc(), vsnprintf().

string_dup()

string * string_dup	(	arena_t *	arena,
		const string *	from )

Duplicates from to a new string.

Allocates a new string with string_new(), and copies the contents to the new string.

Parameters

arena	The arena to allocate from.
from	The string to duplicate.

Precondition

arena and from must be valid and cannot be null.

Returns

A pointer to the new string.

See also

string_new()

string_find_sstr()

i64 string_find_sstr	(	string *	haystack,
		string *	needle )

Finds the first occurance of a string in a string.

Parameters

haystack	the string to search in.
needle	the string to search for.

Precondition

haystack and needle must be valid and cannot be null.

Returns

The index of the first occurance of the string, or -1 if not found.

string_findc()

i64 string_findc	(	string *	haystack,
		u8	needle )

Finds the first occurence of a character in a string.

Parameters

haystack	the string to search in.
needle	The character to search for.

Precondition

haystack and needle must be valid and cannot be null.

Returns

The index of the first occurance of the character, or -1 if not.

string_from_cstr()

string * string_from_cstr	(	arena_t *	arena,
		const cstr *	base )

Create a string from a C-string.

Since string is a wrapper around the C-string pretty much, It simply creates a new string with string_new(), and then copies the contents of the C-string to the new string calculating the string's length with strlen().

Parameters

arena	The arena to allocate from.
base	The C-string to create the string from.

Precondition

arena and base must be valid and cannot be null.

Returns

A pointer to the new string.

See also

string_new(), strlen().

string_new()

string * string_new	(	arena_t *	arena,
		const u64	len )

Creates a new string.

Allocates a string header and its backing buffer with arena_alloc(). The contents are left uninitialized.

Parameters

arena	The arena to allocate from.
len	The length for the string.

Precondition

• arena must be valid and cannot be null.
• len must be greater than 0.

Returns

A pointer to the new string.

See also

arena_alloc()

string_slice_from_cstr()

string_slice string_slice_from_cstr	(	u8 *	base,
		u64	len )

Create a string_slice from a C-string.

We're using string_slice as a term to represent a value instead of a pointer, to have less dependents on arena allocations.

Parameters

base	The C-string to create the string_slice from.
len	The length of the C-string.

Precondition

• base must be valid and cannot be null.
• len must be greater than 0.

Returns

A string_slice.

string_slice_from_string()

string_slice string_slice_from_string

(

string *

str

)

Create a string_slice from a string.

We're using string_slice as a term to represent a value instead of a pointer, to have less dependents on arena allocations, this is basically the same as string_slice_from_cstr() but for passing a string pointer instead for simply convenience reasons.

Parameters

str	The string to create the string_slice from.

Precondition

str must be valid and cannot be null.

Returns

A string_slice.

string_split()

u64 string_split	(	string *	src,
		u8	delim,
		string ***	darray,
		arena_t *	arena )

Splits a string by a delimiter.

Create a dynamic array of string in darray separated by delim.

Parameters

src	The string to split.
delim	The delimiter to split by.
darray	The dynamic array to store the split strings in.
arena	The arena to allocate the dynamic array from.

Precondition

• src, darray, and arena must be valid and cannot be null.
• delim must be greater than 0.

Returns

The length of the dynamic array.

string_to_cstr()

cstr * string_to_cstr

(

const string *

str

)

Convert a string to a cstr.

Casts the base param of string and then null-terminates the end of the base, and then returns it.

Note

Null-terminates in place, writing to the string's buffer. A string_slice must have a spare byte at len (a full string does).

Precondition

• str must be valid and cannot be null.
• str must not be empty.

Parameters

str	The string to convert.

Returns

A pointer to the cstr.

See also

string, cstr

string_trim()

void string_trim

(

string *

str

)

Trims whitespace from the start and end of a string.

Parameters

str	The string to trim.

Precondition

str must be valid and cannot be null.

string_trim_left()

void string_trim_left

(

string *

str

)

Trims whitespace from the start of a string.

Parameters

str	The string to trim.

Precondition

str must be valid and cannot be null.

string_trim_right()

void string_trim_right

(

string *

str

)

Trims whitespace from the end of a string.

Parameters

str	The string to trim.

Precondition

str must be valid and cannot be null.

stringcmp()

b32 stringcmp	(	const string *	first,
		const string *	second )

Compare two string.

Compare the length and the base of 2 string to check if they're equal using memcmp().

Parameters

first	The first string to compare.
second	The second string to compare.

Precondition

first and second must be valid and cannot be null.

Returns

True if equal, false if not.

See also

string, memcmp()

stringcmpb()

b32 stringcmpb	(	const string *	first,
		const string *	second,
		const u64	len )

Compares len bytes of each string.

Compares len bytes of each string to check if they're equal.

Parameters

first	The first string to compare.
second	The second string to compare.
len	The length of the bytes to compare.

Returns

True if the string are equal, false if they're not.