027's 5c: money as i64 minor units shown by .Nd: NUM_TEXT's decimal form takes digits (bits 20-24 as FIXED's), an integer's last N digits written after a point (1234 at two is 12.34, -5 -0.05, 0 0.00; width and zeros after the sign), verification allowing digits on FIXED and DECIMAL alone; unit test: ten rows of formats_and_held (-2^63 at two, 25 digits, a number's whole 1234, its 12.5 a limit); TPC-C's money i64 cents and its rates ten-thousandths (tables, messages, load, the transactions), SQLite's INTEGER columns and int64 bindings alike, the comparison now exact (no 1e-9 tolerance): after 20,000 transactions every row of every table the same (grouped SQLite too) and 3.3.2 holding on both; counts: b45 against b44 BFS without batches +0.09%, the rest within 0.001%; the bank's queries (s44 and s45 in turns, six each) in_credit -0.59%, per_branch -0.34%, ranks -0.20%, the rest within 0.01%, the seven answers the same bytes; 008 (NUM_TEXT's digits, a message row's i64 cells), 027 and 092

3 files changed, 27 insertions, 8 deletions

diff --git a/core/module.c b/core/module.c
index ca5b0e2..3657843 100644
--- a/core/module.c
+++ b/core/module.c
@@ -453,10 +453,10 @@ PURE_COLD static bool names_arg(const PureModule *m, unsigned kind, uint32_t arg
     case A_POSITION: case A_JOINED: return arg <= 1;
     case A_HELD: return (arg & ~(uint32_t)PURE_HELD_APPEND) < PURE_MODULE_HELD;
     case A_FUNCTION: return arg < m->functions;
-    case A_FORMAT: { /* a type; a width, zeros, a form fitting it and digits for FIXED alone */
+    case A_FORMAT: { /* a type; a width, zeros, a form fitting it and digits for FIXED and DECIMAL alone */
         uint32_t type = arg & 3, form = arg >> PURE_FORMAT_FORM & 7, digits = arg >> PURE_FORMAT_DIGITS & 31;
         return type <= 2 && !(arg & 0xFC) && !(arg >> 25) && form <= PURE_FORMAT_FIXED && (type != 1 || !form) &&
-               (form != PURE_FORMAT_FIXED || type == 0) && (form == PURE_FORMAT_FIXED || !digits);
+               (form != PURE_FORMAT_FIXED || type == 0) && (form == PURE_FORMAT_FIXED || form == PURE_FORMAT_DECIMAL || !digits);
     }
     case A_RELATION: return arg <= PURE_NOT_EQUAL;
     case A_KEYED: return state_of(m, arg, PURE_STATE_LIST) && m->state_key[arg];
@@ -2942,7 +2942,8 @@ static __attribute__((cold, noinline)) int kept_step(PureApp *app, PureArena *ar
 }
 
 /* NUM_TEXT's text of v in a format (the argument past its type, PureFormat): false where an integer's form meets a
- * number that is not a whole one within 2^53. */
+ * number that is not a whole one within 2^53. DECIMAL with digits writes the integer in minor units: its last
+ * digits after a point (money's cents: 1234 at two is 12.34, -5 is -0.05). */
 static bool formatted(Slot v, uint32_t arg, char *out, size_t *length) {
     unsigned type = arg & 3, width = arg >> PURE_FORMAT_WIDTH & 0xFF, form = arg >> PURE_FORMAT_FORM & 7,
              digits = arg >> PURE_FORMAT_DIGITS & 31;
@@ -2960,10 +2961,14 @@ static bool formatted(Slot v, uint32_t arg, char *out, size_t *length) {
         unsigned base = form == PURE_FORMAT_DECIMAL ? 10 : form <= PURE_FORMAT_HEX_UPPER ? 16 : form == PURE_FORMAT_BINARY ? 2 : 8;
         const char *set = form == PURE_FORMAT_HEX_UPPER ? "0123456789ABCDEF" : "0123456789abcdef";
         char reversed[64];
-        unsigned count = 0;
+        unsigned count = 0, places = form == PURE_FORMAT_DECIMAL && digits ? digits - 1 : 0;
         do reversed[count++] = set[magnitude % base], magnitude /= base; while (magnitude);
+        while (count <= places) reversed[count++] = '0'; /* a digit before the point */
         if (i < 0) body[n++] = '-';
-        while (count) body[n++] = reversed[--count];
+        for (; count; --count) {
+            if (count == places) body[n++] = '.';
+            body[n++] = reversed[count - 1];
+        }
     } else
         n = type == 2 ? (size_t)snprintf(body, sizeof(body), "%" PRId64, v.i64)
           : type ? (size_t)snprintf(body, sizeof(body), "%s", v.num ? "true" : "false") : pure_format_number(v.num, body);
diff --git a/core/module.h b/core/module.h
index ce8cebf..75e27ba 100644
--- a/core/module.h
+++ b/core/module.h
@@ -101,8 +101,10 @@ typedef enum { PURE_BITS_AND, PURE_BITS_OR, PURE_BITS_XOR, PURE_BITS_LEFT, PURE_
  * NUM_TEXT's argument: bits 0-1 the value's type (as CONST's), 8-15 a width
  * the text is padded to on the left, bit 16 padding with zeros after a sign
  * (else spaces), 17-19 the form (PureFormat), 20-24 one more than the digits
- * after the point of FIXED. A form of an integer takes an i64 or a whole
- * number (else LIMIT), in its base with a sign; FIXED takes a number. */
+ * after the point of FIXED or of DECIMAL (there the integer in minor units:
+ * 1234 at two digits is 12.34, as money's cents). A form of an integer takes
+ * an i64 or a whole number (else LIMIT), in its base with a sign; FIXED
+ * takes a number. */
 enum { PURE_MODULE_HELD = 32, PURE_HELD_TEXT = 16, PURE_HELD_APPEND = 1 << 8 };
 /* 027's stage 2b: lists in records. A record field of type LIST holds a list
  * of the record its default names. In an event's list (and the lists in its
diff --git a/core/test-module.c b/core/test-module.c
index 36722d2..f89e198 100644
--- a/core/test-module.c
+++ b/core/test-module.c
@@ -6166,7 +6166,8 @@ static void bits_and_bytes(void) {
 
 /* ---- Formats, slices and values held by name (docs/design/027, stage 2a) --
  * NUM_TEXT writes a number, a bool or an i64 in a width, with zeros or
- * spaces, in a base or with fixed digits; an integer's form fails as limit
+ * spaces, in a base or with fixed digits, or an integer in minor units
+ * (money's: 1234 at two digits is 12.34); an integer's form fails as limit
  * on a number that is not whole. BYTES_SLICE takes whole positions inside
  * the value; BYTE makes one byte. BYTES_LOAD and BYTES_STORE keep bytes
  * and texts by name for the event (a text's slots hold text alone): set,
@@ -6194,6 +6195,17 @@ static void formats_and_held(void) {
         {0, 42, FMT(0, 0, 0, PURE_FORMAT_HEX, 0), PURE_FAULT_NONE, "2a"},
         {0, 2.5, FMT(0, 0, 0, PURE_FORMAT_HEX, 0), PURE_FAULT_LIMIT, ""},
         {0, 1, FMT(1, 6, 0, PURE_FORMAT_PLAIN, 0), PURE_FAULT_NONE, "  true"},
+        /* Money's form (027's stage 5): an integer in minor units, its last digits after a point. */
+        {1, 1234, FMT(2, 0, 0, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_NONE, "12.34"},
+        {1, -5, FMT(2, 0, 0, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_NONE, "-0.05"},
+        {1, 0, FMT(2, 0, 0, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_NONE, "0.00"},
+        {1, -5, FMT(2, 7, 1, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_NONE, "-000.05"},
+        {1, 100, FMT(2, 6, 0, PURE_FORMAT_DECIMAL, 2), PURE_FAULT_NONE, "  10.0"},
+        {1, 7, FMT(2, 0, 0, PURE_FORMAT_DECIMAL, 1), PURE_FAULT_NONE, "7"},
+        {1, 5, FMT(2, 0, 0, PURE_FORMAT_DECIMAL, 26), PURE_FAULT_NONE, "0.0000000000000000000000005"},
+        {1, -0x1p63, FMT(2, 0, 0, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_NONE, "-92233720368547758.08"},
+        {0, 1234, FMT(0, 0, 0, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_NONE, "12.34"},
+        {0, 12.5, FMT(0, 0, 0, PURE_FORMAT_DECIMAL, 3), PURE_FAULT_LIMIT, ""},
     };
     for (size_t k = 0; k < LEN(shown); ++k) {
         O value = shown[k].i64 ? IC((int64_t)shown[k].value) : (O){C, shown[k].format & 3, shown[k].value};