str.jou

# Functions for working with strings (byte* pointers).

# Parsing. See also scanf() in io.jou.
@public
declare sscanf(s: byte*, pattern: byte*, ...) -> int  # Parse a string. See sscanf() in io.jou.

# Formatting. See also printf() in io.jou.
#   sprintf() assumes that the result fits in dest (UB happens, if it overflows)
#   snprintf() truncates the string so that the string and its '\0' fit into a total of n bytes of space
@public
declare sprintf(dest: byte*, pattern: byte*, ...) -> int
@public
declare snprintf(dest: byte*, n: long, pattern: byte*, ...) -> int

# Find a substring. Return a pointer to the first occurrence in haystack, or NULL if not found.
@public
declare strstr(haystack: byte*, needle: byte*) -> byte*

# Find a byte from a string. Return a pointer to the occurrence, or NULL if not found.
@public
declare strchr(haystack: byte*, needle: byte) -> byte*  # finds first occurrence
@public
declare strrchr(haystack: byte*, needle: byte) -> byte*  # finds last occurrence

# Calculate the length of a string in bytes. Note that strlen("ö") == 2, for example.
@public
declare strlen(s: byte*) -> long

# Compare the strings. Return 0 for equal, or nonzero for not equal.
@public
declare strcmp(s1: byte*, s2: byte*) -> int

# Similar to strcmp(), but imagines the strings are at most n bytes long.
# In other words, if s1 or s2 is more than n bytes long, the rest is not compared.
@public
declare strncmp(s1: byte*, s2: byte*, n: long) -> int

# Returns true if the string s starts with the given prefix.
@public
def starts_with(s: byte*, prefix: byte*) -> bool:
    return strncmp(s, prefix, strlen(prefix)) == 0

# Returns true if the string s ends with the given prefix.
@public
def ends_with(s: byte*, suffix: byte*) -> bool:
    offset = strlen(s) - strlen(suffix)
    return offset >= 0 and strcmp(&s[offset], suffix) == 0

# Return how many bytes at start of s appear in the accept string.
# For example, you can use strspn(s, " \t") to get the amount of indentation.
@public
declare strspn(s: byte*, accept: byte*) -> long

# Return how many bytes at start of s do not appear in the reject string.
# For example, you can use strcspn(s, "\n") to get the length of the first line.
@public
declare strcspn(s: byte*, reject: byte*) -> long

# Copy a string. Assumes it fits. Returned value is dest.
@public
declare strcpy(dest: byte*, source: byte*) -> byte*

# Append source to end of dest. Assumes it fits. Returned value is dest.
# Can be slow if dest is long, because it needs to find the end of dest.
@public
declare strcat(dest: byte*, source: byte*) -> byte*

# Return a newly allocated (as in malloc()) copy of the string.
@public
declare strdup(s: byte*) -> byte*

# Convert a string to an int.
# Returns 0 on error, and ignores junk at end: atoi("123foo") == 123
@public
declare atoi(s: byte*) -> int
@public
declare atoll(s: byte*) -> long