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Code

Support EEEE (scientific notation) in to_char().

Browse Source 
Pavel Stehule, Brendan Jurd
This commit is contained in:
Tom Lane 2009-08-10 18:29:27 +00:00
parent 933b17b663
commit e61fd4ac74
6 changed files with 347 additions and 14 deletions
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17
doc/src/sgml/func.sgml
View File

@ -1,4 +1,4 @@
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.485 2009/08/10 16:10:19 tgl Exp $ -->
<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.486 2009/08/10 18:29:26 tgl Exp $ -->
<chapter id="functions">
<title>Functions and Operators</title>
@ -5345,7 +5345,7 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
</row>
<row>
<entry><literal>EEEE</literal></entry>
<entry>scientific notation (not implemented)</entry>
<entry>exponent for scientific notation</entry>
</row>
</tbody>
</tgroup>
@ -5404,6 +5404,15 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
(e.g., <literal>99.9V99</literal> is not allowed).
</para>
</listitem>
<listitem>
<para>
<literal>EEEE</literal> (scientific notation) cannot be used in
combination with any of the other special formatting patterns or
modifiers, and must be at the end of the format string
(e.g., <literal>9.99EEEE</literal> is a valid pattern).
</para>
</listitem>
</itemizedlist>
</para>
@ -5605,6 +5614,10 @@ SELECT SUBSTRING('XY1234Z', 'Y*?([0-9]{1,3})');
<entry><literal>to_char(12.45, '99V9')</literal></entry>
<entry><literal>'&nbsp;125'</literal></entry>
</row>
<row>
<entry><literal>to_char(0.0004859, '9.99EEEE')</literal></entry>
<entry><literal>' 4.86e-04'</literal></entry>
</row>
</tbody>
</tgroup>
</table>

184
src/backend/utils/adt/formatting.c
View File

@ -1,7 +1,7 @@
/* -----------------------------------------------------------------------
* formatting.c
*
* $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.159 2009/07/06 19:11:39 heikki Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/formatting.c,v 1.160 2009/08/10 18:29:26 tgl Exp $
*
*
* Portions Copyright (c) 1999-2009, PostgreSQL Global Development Group
@ -335,6 +335,7 @@ typedef struct
#define NUM_F_MULTI (1 << 11)
#define NUM_F_PLUS_POST (1 << 12)
#define NUM_F_MINUS_POST (1 << 13)
#define NUM_F_EEEE (1 << 14)
#define NUM_LSIGN_PRE (-1)
#define NUM_LSIGN_POST 1
@ -355,6 +356,7 @@ typedef struct
#define IS_PLUS(_f) ((_f)->flag & NUM_F_PLUS)
#define IS_ROMAN(_f) ((_f)->flag & NUM_F_ROMAN)
#define IS_MULTI(_f) ((_f)->flag & NUM_F_MULTI)
#define IS_EEEE(_f) ((_f)->flag & NUM_F_EEEE)
/* ----------
* Format picture cache
@ -821,7 +823,7 @@ static const KeyWord NUM_keywords[] = {
{"B", 1, NUM_B}, /* B */
{"C", 1, NUM_C}, /* C */
{"D", 1, NUM_D}, /* D */
{"E", 1, NUM_E}, /* E */
{"EEEE", 4, NUM_E}, /* E */
{"FM", 2, NUM_FM}, /* F */
{"G", 1, NUM_G}, /* G */
{"L", 1, NUM_L}, /* L */
@ -837,7 +839,7 @@ static const KeyWord NUM_keywords[] = {
{"b", 1, NUM_B}, /* b */
{"c", 1, NUM_C}, /* c */
{"d", 1, NUM_D}, /* d */
{"e", 1, NUM_E}, /* e */
{"eeee", 4, NUM_E}, /* e */
{"fm", 2, NUM_FM}, /* f */
{"g", 1, NUM_G}, /* g */
{"l", 1, NUM_L}, /* l */
@ -1044,6 +1046,14 @@ NUMDesc_prepare(NUMDesc *num, FormatNode *n)
if (n->type != NODE_TYPE_ACTION)
return;
if (IS_EEEE(num) && n->key->id != NUM_E)
{
NUM_cache_remove(last_NUMCacheEntry);
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"EEEE\" must be the last pattern used")));
}
switch (n->key->id)
{
case NUM_9:
@ -1217,10 +1227,25 @@ NUMDesc_prepare(NUMDesc *num, FormatNode *n)
break;
case NUM_E:
if (IS_EEEE(num))
{
NUM_cache_remove(last_NUMCacheEntry);
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("\"E\" is not supported")));
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot use \"EEEE\" twice")));
}
if (IS_BLANK(num) || IS_FILLMODE(num) || IS_LSIGN(num) ||
IS_BRACKET(num) || IS_MINUS(num) || IS_PLUS(num) ||
IS_ROMAN(num) || IS_MULTI(num))
{
NUM_cache_remove(last_NUMCacheEntry);
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("\"EEEE\" is incompatible with other formats"),
errdetail("\"EEEE\" may only be used together with digit and decimal point patterns.")));
}
num->flag |= NUM_F_EEEE;
break;
}
return;
@ -4145,6 +4170,15 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number,
if (Np->Num->zero_start)
--Np->Num->zero_start;
if (IS_EEEE(Np->Num))
{
if (!Np->is_to_char)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("\"EEEE\" not supported for input")));
return strcpy(inout, number);
}
/*
* Roman correction
*/
@ -4153,7 +4187,7 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number,
if (!Np->is_to_char)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("\"RN\" not supported")));
errmsg("\"RN\" not supported for input")));
Np->Num->lsign = Np->Num->pre_lsign_num = Np->Num->post =
Np->Num->pre = Np->num_pre = Np->sign = 0;
@ -4240,7 +4274,7 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number,
#ifdef DEBUG_TO_FROM_CHAR
elog(DEBUG_elog_output,
"\n\tSIGN: '%c'\n\tNUM: '%s'\n\tPRE: %d\n\tPOST: %d\n\tNUM_COUNT: %d\n\tNUM_PRE: %d\n\tSIGN_WROTE: %s\n\tZERO: %s\n\tZERO_START: %d\n\tZERO_END: %d\n\tLAST_RELEVANT: %s\n\tBRACKET: %s\n\tPLUS: %s\n\tMINUS: %s\n\tFILLMODE: %s\n\tROMAN: %s",
"\n\tSIGN: '%c'\n\tNUM: '%s'\n\tPRE: %d\n\tPOST: %d\n\tNUM_COUNT: %d\n\tNUM_PRE: %d\n\tSIGN_WROTE: %s\n\tZERO: %s\n\tZERO_START: %d\n\tZERO_END: %d\n\tLAST_RELEVANT: %s\n\tBRACKET: %s\n\tPLUS: %s\n\tMINUS: %s\n\tFILLMODE: %s\n\tROMAN: %s\n\tEEEE: %s",
Np->sign,
Np->number,
Np->Num->pre,
@ -4256,7 +4290,8 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number,
IS_PLUS(Np->Num) ? "Yes" : "No",
IS_MINUS(Np->Num) ? "Yes" : "No",
IS_FILLMODE(Np->Num) ? "Yes" : "No",
IS_ROMAN(Np->Num) ? "Yes" : "No"
IS_ROMAN(Np->Num) ? "Yes" : "No",
IS_EEEE(Np->Num) ? "Yes" : "No"
);
#endif
@ -4626,6 +4661,39 @@ numeric_to_char(PG_FUNCTION_ARGS)
int_to_roman(DatumGetInt32(DirectFunctionCall1(numeric_int4,
NumericGetDatum(x))));
}
else if (IS_EEEE(&Num))
{
orgnum = numeric_out_sci(value, Num.post);
/*
* numeric_out_sci() does not emit a sign for positive numbers. We
* need to add a space in this case so that positive and negative
* numbers are aligned. We also have to do the right thing for NaN.
*/
if (strcmp(orgnum, "NaN") == 0)
{
/*
* Allow 6 characters for the leading sign, the decimal point, "e",
* the exponent's sign and two exponent digits.
*/
numstr = (char *) palloc(Num.pre + Num.post + 7);
fill_str(numstr, '#', Num.pre + Num.post + 6);
*numstr = ' ';
*(numstr + Num.pre + 1) = '.';
}
else if (*orgnum != '-')
{
numstr = (char *) palloc(strlen(orgnum) + 2);
*numstr = ' ';
strcpy(numstr + 1, orgnum);
len = strlen(numstr);
}
else
{
numstr = orgnum;
len = strlen(orgnum);
}
}
else
{
Numeric val = value;
@ -4707,6 +4775,23 @@ int4_to_char(PG_FUNCTION_ARGS)
*/
if (IS_ROMAN(&Num))
numstr = orgnum = int_to_roman(value);
else if (IS_EEEE(&Num))
{
/* we can do it easily because float8 won't lose any precision */
float8 val = (float8) value;
orgnum = (char *) palloc(MAXDOUBLEWIDTH + 1);
snprintf(orgnum, MAXDOUBLEWIDTH + 1, "%+.*e", Num.post, val);
/*
* Swap a leading positive sign for a space.
*/
if (*orgnum == '+')
*orgnum = ' ';
len = strlen(orgnum);
numstr = orgnum;
}
else
{
if (IS_MULTI(&Num))
@ -4785,6 +4870,33 @@ int8_to_char(PG_FUNCTION_ARGS)
numstr = orgnum = int_to_roman(DatumGetInt32(
DirectFunctionCall1(int84, Int64GetDatum(value))));
}
else if (IS_EEEE(&Num))
{
/* to avoid loss of precision, must go via numeric not float8 */
Numeric val;
val = DatumGetNumeric(DirectFunctionCall1(int8_numeric,
Int64GetDatum(value)));
orgnum = numeric_out_sci(val, Num.post);
/*
* numeric_out_sci() does not emit a sign for positive numbers. We
* need to add a space in this case so that positive and negative
* numbers are aligned. We don't have to worry about NaN here.
*/
if (*orgnum != '-')
{
numstr = (char *) palloc(strlen(orgnum) + 2);
*numstr = ' ';
strcpy(numstr + 1, orgnum);
len = strlen(numstr);
}
else
{
numstr = orgnum;
len = strlen(orgnum);
}
}
else
{
if (IS_MULTI(&Num))
@ -4859,6 +4971,34 @@ float4_to_char(PG_FUNCTION_ARGS)
if (IS_ROMAN(&Num))
numstr = orgnum = int_to_roman((int) rint(value));
else if (IS_EEEE(&Num))
{
numstr = orgnum = (char *) palloc(MAXDOUBLEWIDTH + 1);
if (isnan(value) || is_infinite(value))
{
/*
* Allow 6 characters for the leading sign, the decimal point, "e",
* the exponent's sign and two exponent digits.
*/
numstr = (char *) palloc(Num.pre + Num.post + 7);
fill_str(numstr, '#', Num.pre + Num.post + 6);
*numstr = ' ';
*(numstr + Num.pre + 1) = '.';
}
else
{
snprintf(orgnum, MAXDOUBLEWIDTH + 1, "%+.*e", Num.post, value);
/*
* Swap a leading positive sign for a space.
*/
if (*orgnum == '+')
*orgnum = ' ';
len = strlen(orgnum);
numstr = orgnum;
}
}
else
{
float4 val = value;
@ -4935,6 +5075,34 @@ float8_to_char(PG_FUNCTION_ARGS)
if (IS_ROMAN(&Num))
numstr = orgnum = int_to_roman((int) rint(value));
else if (IS_EEEE(&Num))
{
numstr = orgnum = (char *) palloc(MAXDOUBLEWIDTH + 1);
if (isnan(value) || is_infinite(value))
{
/*
* Allow 6 characters for the leading sign, the decimal point, "e",
* the exponent's sign and two exponent digits.
*/
numstr = (char *) palloc(Num.pre + Num.post + 7);
fill_str(numstr, '#', Num.pre + Num.post + 6);
*numstr = ' ';
*(numstr + Num.pre + 1) = '.';
}
else
{
snprintf(orgnum, MAXDOUBLEWIDTH + 1, "%+.*e", Num.post, value);
/*
* Swap a leading positive sign for a space.
*/
if (*orgnum == '+')
*orgnum = ' ';
len = strlen(orgnum);
numstr = orgnum;
}
}
else
{
float8 val = value;

133
src/backend/utils/adt/numeric.c
View File

@ -14,7 +14,7 @@
* Copyright (c) 1998-2009, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.118 2009/06/11 14:49:03 momjian Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/numeric.c,v 1.119 2009/08/10 18:29:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -247,6 +247,7 @@ static const char *set_var_from_str(const char *str, const char *cp,
static void set_var_from_num(Numeric value, NumericVar *dest);
static void set_var_from_var(NumericVar *value, NumericVar *dest);
static char *get_str_from_var(NumericVar *var, int dscale);
static char *get_str_from_var_sci(NumericVar *var, int rscale);
static Numeric make_result(NumericVar *var);
@ -426,6 +427,32 @@ numeric_out(PG_FUNCTION_ARGS)
PG_RETURN_CSTRING(str);
}
/*
* numeric_out_sci() -
*
* Output function for numeric data type in scientific notation.
*/
char *
numeric_out_sci(Numeric num, int scale)
{
NumericVar x;
char *str;
/*
* Handle NaN
*/
if (NUMERIC_IS_NAN(num))
return pstrdup("NaN");
init_var(&x);
set_var_from_num(num, &x);
str = get_str_from_var_sci(&x, scale);
free_var(&x);
return str;
}
/*
* numeric_recv - converts external binary format to numeric
*
@ -3364,6 +3391,110 @@ get_str_from_var(NumericVar *var, int dscale)
return str;
}
/*
* get_str_from_var_sci() -
*
* Convert a var to a normalised scientific notation text representation.
* This function does the heavy lifting for numeric_out_sci().
*
* This notation has the general form a * 10^b, where a is known as the
* "significand" and b is known as the "exponent".
*
* Because we can't do superscript in ASCII (and because we want to copy
* printf's behaviour) we display the exponent using E notation, with a
* minimum of two exponent digits.
*
* For example, the value 1234 could be output as 1.2e+03.
*
* We assume that the exponent can fit into an int32.
*
* rscale is the number of decimal digits desired after the decimal point in
* the output, negative values will be treated as meaning zero.
*
* CAUTION: var's contents may be modified by rounding!
*
* Returns a palloc'd string.
*/
static char *
get_str_from_var_sci(NumericVar *var, int rscale)
{
int32 exponent;
NumericVar denominator;
NumericVar significand;
int denom_scale;
size_t len;
char *str;
char *sig_out;
if (rscale < 0)
rscale = 0;
/*
* Determine the exponent of this number in normalised form.
*
* This is the exponent required to represent the number with only one
* significant digit before the decimal place.
*/
if (var->ndigits > 0)
{
exponent = (var->weight + 1) * DEC_DIGITS;
/*
* Compensate for leading decimal zeroes in the first numeric digit by
* decrementing the exponent.
*/
exponent -= DEC_DIGITS - (int) log10(var->digits[0]);
}
else
{
/*
* If var has no digits, then it must be zero.
*
* Zero doesn't technically have a meaningful exponent in normalised
* notation, but we just display the exponent as zero for consistency
* of output.
*/
exponent = 0;
}
/*
* The denominator is set to 10 raised to the power of the exponent.
*
* We then divide var by the denominator to get the significand, rounding
* to rscale decimal digits in the process.
*/
if (exponent < 0)
denom_scale = -exponent;
else
denom_scale = 0;
init_var(&denominator);
init_var(&significand);
int8_to_numericvar((int64) 10, &denominator);
power_var_int(&denominator, exponent, &denominator, denom_scale);
div_var(var, &denominator, &significand, rscale, true);
sig_out = get_str_from_var(&significand, rscale);
free_var(&denominator);
free_var(&significand);
/*
* Allocate space for the result.
*
* In addition to the significand, we need room for the exponent decoration
* ("e"), the sign of the exponent, up to 10 digits for the exponent
* itself, and of course the null terminator.
*/
len = strlen(sig_out) + 13;
str = palloc(len);
snprintf(str, len, "%se%+03d", sig_out, exponent);
pfree(sig_out);
return str;
}
/*
* make_result() -

7
src/include/utils/numeric.h
View File

@ -7,7 +7,7 @@
*
* Copyright (c) 1998-2009, PostgreSQL Global Development Group
*
* $PostgreSQL: pgsql/src/include/utils/numeric.h,v 1.27 2009/01/01 17:24:02 momjian Exp $
* $PostgreSQL: pgsql/src/include/utils/numeric.h,v 1.28 2009/08/10 18:29:27 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -84,4 +84,9 @@ typedef NumericData *Numeric;
#define PG_GETARG_NUMERIC_COPY(n) DatumGetNumericCopy(PG_GETARG_DATUM(n))
#define PG_RETURN_NUMERIC(x) return NumericGetDatum(x)
/*
* Utility functions in numeric.c
*/
extern char *numeric_out_sci(Numeric num, int scale);
#endif /* _PG_NUMERIC_H_ */

15
src/test/regress/expected/numeric.out
View File

@ -1139,6 +1139,21 @@ SELECT '' AS to_char_22, to_char(val, 'FM9999999999999999.999999999999999') FROM
| -24926804.04504742
(10 rows)
SELECT '' AS to_char_23, to_char(val, '9.999EEEE') FROM num_data;
to_char_23 | to_char
------------+------------
| 0.000e+00
| 0.000e+00
| -3.434e+07
| 4.310e+00
| 7.799e+06
| 1.640e+04
| 9.390e+04
| -8.303e+07
| 7.488e+04
| -2.493e+07
(10 rows)
-- TO_NUMBER()
--
SELECT '' AS to_number_1, to_number('-34,338,492', '99G999G999');

1
src/test/regress/sql/numeric.sql
View File

@ -762,6 +762,7 @@ SELECT '' AS to_char_19, to_char(val, 'FMS 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 . 9 9
SELECT '' AS to_char_20, to_char(val, E'99999 "text" 9999 "9999" 999 "\\"text between quote marks\\"" 9999') FROM num_data;
SELECT '' AS to_char_21, to_char(val, '999999SG9999999999') FROM num_data;
SELECT '' AS to_char_22, to_char(val, 'FM9999999999999999.999999999999999') FROM num_data;
SELECT '' AS to_char_23, to_char(val, '9.999EEEE') FROM num_data;
-- TO_NUMBER()
--