зеркало из https://github.com/github/ruby.git
127 строки
3.8 KiB
C
127 строки
3.8 KiB
C
/**
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* @file pm_integer.h
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*
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* This module provides functions for working with arbitrary-sized integers.
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*/
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#ifndef PRISM_NUMBER_H
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#define PRISM_NUMBER_H
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#include "prism/defines.h"
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#include "prism/util/pm_buffer.h"
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#include <assert.h>
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#include <stdbool.h>
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#include <stdint.h>
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#include <stdlib.h>
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/**
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* A structure represents an arbitrary-sized integer.
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*/
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typedef struct {
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/**
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* The number of allocated values. length is set to 0 if the integer fits
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* into uint32_t.
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*/
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size_t length;
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/**
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* List of 32-bit integers. Set to NULL if the integer fits into uint32_t.
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*/
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uint32_t *values;
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/**
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* Embedded value for small integer. This value is set to 0 if the value
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* does not fit into uint32_t.
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*/
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uint32_t value;
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/**
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* Whether or not the integer is negative. It is stored this way so that a
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* zeroed pm_integer_t is always positive zero.
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*/
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bool negative;
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} pm_integer_t;
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/**
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* An enum controlling the base of an integer. It is expected that the base is
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* already known before parsing the integer, even though it could be derived
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* from the string itself.
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*/
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typedef enum {
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/** The default decimal base, with no prefix. Leading 0s will be ignored. */
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PM_INTEGER_BASE_DEFAULT,
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/** The binary base, indicated by a 0b or 0B prefix. */
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PM_INTEGER_BASE_BINARY,
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/** The octal base, indicated by a 0, 0o, or 0O prefix. */
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PM_INTEGER_BASE_OCTAL,
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/** The decimal base, indicated by a 0d, 0D, or empty prefix. */
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PM_INTEGER_BASE_DECIMAL,
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/** The hexadecimal base, indicated by a 0x or 0X prefix. */
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PM_INTEGER_BASE_HEXADECIMAL,
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/**
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* An unknown base, in which case pm_integer_parse will derive it based on
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* the content of the string. This is less efficient and does more
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* comparisons, so if callers know the base ahead of time, they should use
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* that instead.
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*/
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PM_INTEGER_BASE_UNKNOWN
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} pm_integer_base_t;
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/**
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* Parse an integer from a string. This assumes that the format of the integer
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* has already been validated, as internal validation checks are not performed
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* here.
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*
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* @param integer The integer to parse into.
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* @param base The base of the integer.
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* @param start The start of the string.
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* @param end The end of the string.
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*/
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void pm_integer_parse(pm_integer_t *integer, pm_integer_base_t base, const uint8_t *start, const uint8_t *end);
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/**
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* Compare two integers. This function returns -1 if the left integer is less
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* than the right integer, 0 if they are equal, and 1 if the left integer is
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* greater than the right integer.
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*
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* @param left The left integer to compare.
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* @param right The right integer to compare.
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* @return The result of the comparison.
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*/
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int pm_integer_compare(const pm_integer_t *left, const pm_integer_t *right);
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/**
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* Reduce a ratio of integers to its simplest form.
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*
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* If either the numerator or denominator do not fit into a 32-bit integer, then
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* this function is a no-op. In the future, we may consider reducing even the
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* larger numbers, but for now we're going to keep it simple.
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*
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* @param numerator The numerator of the ratio.
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* @param denominator The denominator of the ratio.
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*/
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void pm_integers_reduce(pm_integer_t *numerator, pm_integer_t *denominator);
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/**
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* Convert an integer to a decimal string.
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*
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* @param buffer The buffer to append the string to.
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* @param integer The integer to convert to a string.
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*/
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PRISM_EXPORTED_FUNCTION void pm_integer_string(pm_buffer_t *buffer, const pm_integer_t *integer);
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/**
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* Free the internal memory of an integer. This memory will only be allocated if
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* the integer exceeds the size of a single node in the linked list.
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*
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* @param integer The integer to free.
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*/
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PRISM_EXPORTED_FUNCTION void pm_integer_free(pm_integer_t *integer);
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#endif
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