/** @license 2023 Neil Edelman, distributed under the terms of the [MIT License](https://opensource.org/licenses/MIT). A `pair` is `[a, b)` pair of pointers to char. Used in most string parsing. @std C99 */ #include "pair.h" #include #include #include /** @return Constructs `a` and `b` as a pair [or else (0,0)?]. */ struct pair pair(const char *const a, const char *const b) { struct pair p; assert(a && a <= b); p.a = a, p.b = b; return p; } /** Doesn't check if the number is actually in [0, 9]. @return Whether it was able to parse unsigned [`a`, `b`] to `n`. */ int pair_to_natural(const char *a, const char *const b, uint32_t *const n) { uint32_t accum = 0; while(a < b) { unsigned next = accum * 10 + (unsigned)(*a - '0'); if(accum > next) return errno = ERANGE, 0; accum = next; a++; } return *n = accum, 1; } static int pair_to_64(const char *a, const char *const b, uint64_t *const n) { uint64_t accum = 0; while(a < b) { uint64_t next = accum * 10 + (uint64_t)(*a - '0'); if(accum > next) return errno = ERANGE, 0; accum = next; a++; } return *n = accum, 1; } /** `h0` "1" `h1` ":" `m0` "30" `m1` -> 90 `n` @return Valid. */ int pair_colon_to_minutes(const char *h0, const char *const h1, const char *m0, const char *const m1, uint32_t *const n) { uint32_t hours, minutes; return pair_to_natural(h0, h1, &hours) && pair_to_natural(m0, m1, &minutes) && minutes < 60 && hours <= UINT32_MAX / 60 - minutes ? (*n = hours * 60 + minutes, 1) : 0; } /** `h0` "1" `h1` "." `m0` "5" `m1` -> 90 `n` @return Valid. */ int pair_hours_to_minutes(const char *h0, const char *const h1, const char *m0, const char *const m1, uint32_t *const n) { uint32_t hours, minutes; /* fixme: more precision? */ return pair_to_natural(h0, h1, &hours) && pair_to_natural(m0, m1, &minutes) && minutes <= 9 && hours <= UINT32_MAX / 60 - minutes * 6 ? (*n = hours * 60 + minutes * 6, 1) : 0; } /** @return The content of `x` is the same as `y`. */ int pair_is_equal(struct pair x, struct pair y) { assert(x.a <= x.b && y.a <= y.b); if(!x.a) return !y.a; if(!y.a) return 0; if(x.b - x.a != y.b - y.a) return 0; while(x.a < x.b) { if(*x.a != *y.a) return 0; x.a++, y.a++; } return 1; } /** @return Exact match between a pair `x` (start-end pointers) and a string `y` (null-terminated). */ int pair_is_string(struct pair x, const char *y) { assert(x.a <= x.b); if(!x.a) return !y; if(!y) return 0; while(x.a < x.b) { if(*x.a != *y || !*y) return 0; x.a++, y++; } return !*y; } /** Is `y` a leap-year? */ static int leap(int y) { assert(y >= 1582); if(!(y % 400)) return 1; if(!(y % 100)) return 0; if(!(y % 4)) return 1; return 0; } /** Convert or narrower type or return zero. */ static union date32 date_to_32(const uint32_t y, const uint32_t m, const uint32_t d) { union date32 d32 = { 0 }; /* Leap year calculations only work at y>=1 and Gregorian Calendar and max 23 bits. */ if(y < 1582 || y > 8388607 || m < 1 || m > 12 || d < 1 || d > 31) goto no; switch(m) { case 1: case 3: case 5: case 7: case 8: case 10: case 12: break; case 4: case 6: case 9: case 11: if(d > 30) goto no; break; case 2: if(d > (uint32_t)(28 + leap((int)y))) goto no; break; default: assert(0); break; } d32.year = (unsigned)y, d32.month = (unsigned)m, d32.day = (unsigned)d; no: return d32; } /** `a` represents the start of a date in y...-mm-dd, which is stored in `d`. @return Success. @throws[ERANGE] Year is more then 23 bits. @throws[EILSEQ] The is not a date? */ int pair_to_date(const char *a, union date32 *const d) { uint32_t year = 0, month, day; union date32 temp; assert(a && d); while(*a >= '0' && *a <= '9') { year = year * 10 + (unsigned)(*a - '0'); if(year > 0x7FFFFF) return errno = ERANGE, 0; /* 23 bits */ a++; } if(a[0] != '-' || a[1] == '\0' || a[2] == '\0' || a[3] != '-' || a[4] == '\0' || a[5] == '\0') return errno = EILSEQ, 0; month = (unsigned)(a[1] - '0') * 10 + (unsigned)(a[2] - '0'); day = (unsigned)(a[4] - '0') * 10 + (unsigned)(a[5] - '0'); temp = date_to_32(year, month, day); if(!temp.u32) return errno = EILSEQ, 0; return *d = temp, 1; } int pair_to_cents(const char *a, const char *b, int64_t *const cents) { uint64_t d, c; int is_negative; assert(a && a < b && cents); if(a[0] == '-') is_negative = 1, a++, assert(a < b); else is_negative = 0; if(a + 2 < b && b[-3] == '.') { /* dollars.cents */ if(!pair_to_64(a, b - 3, &d)) return 0; c = (uint64_t)(b[-2] - '0') * 10 + (uint64_t)(b[-1] - '0'); } else { /* dollars */ if(!pair_to_64(a, b, &d)) return 0; c = 0; } assert(-INT64_MAX >= INT64_MIN); if(INT64_MAX / 100 < d || INT64_MAX - d * 100 < c) return errno = ERANGE, 0; /* Misses one in 2's. Not a very nuanced conversion. */ *cents = (is_negative ? -1 : 1) * (int64_t)(d * 100 + c); return 1; } /** @return A djb2 hash of `p`. */ uint32_t pair_djb2(struct pair p) { uint32_t hash = 5381, c; while(p.a < p.b) { c = (unsigned char)*p.a++; hash = ((hash << 5) + hash) + c; /* hash * 33 + c */ } return hash; } #include /* sprintf */ /* Maps from substring keywords to indices, default zero. */ static void pairmap_to_string(const struct pair key, const size_t i, char (*const a)[12]) { (void)key; sprintf(*a, "%zu", i); } static int pairmap_is_equal(const struct pair a, const struct pair b) { return pair_is_equal(a, b); } static uint32_t pairmap_hash(const struct pair p) { return pair_djb2(p); } #define TABLE_NAME pairmap #define TABLE_KEY struct pair #define TABLE_UINT uint32_t #define TABLE_VALUE size_t #define TABLE_DEFAULT 0 /* Default set at zero. */ #define TABLE_TO_STRING #define TABLE_BODY #include "../src/table.h" struct pairmap_table pair_map_table(void) { return pairmap_table(); } void pair_map_table_(struct pairmap_table *const t) { pairmap_table_(t); } const char *pair_map_table_to_string(const struct pairmap_table *const t) { return pairmap_table_to_string(t); } enum table_result pair_map_table_assign(struct pairmap_table *const t, const struct pair key, size_t **const content) { return pairmap_table_assign(t, key, content); } size_t pair_map_table_get(struct pairmap_table *const t, const struct pair key) { return pairmap_table_get(t, key); }