diff options
Diffstat (limited to 'src/include/nodes/pg_list.h')
| -rw-r--r-- | src/include/nodes/pg_list.h | 26 |
1 files changed, 20 insertions, 6 deletions
diff --git a/src/include/nodes/pg_list.h b/src/include/nodes/pg_list.h index 94aa8d58c6b..9f05bc7985f 100644 --- a/src/include/nodes/pg_list.h +++ b/src/include/nodes/pg_list.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: pg_list.h,v 1.15 2000/02/06 03:27:35 tgl Exp $ + * $Id: pg_list.h,v 1.16 2000/02/21 18:47:12 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -23,6 +23,21 @@ /*---------------------- * Value node + * + * The same Value struct is used for three node types: T_Integer, + * T_Float, and T_String. Integral values are actually represented + * by a machine integer, but both floats and strings are represented + * as strings. Using T_Float as the node type simply indicates that + * the contents of the string look like a valid numeric literal. + * + * (Before Postgres 7.0, we used a double to represent T_Float, + * but that creates loss-of-precision problems when the value is + * ultimately destined to be converted to NUMERIC. Since Value nodes + * are only used in the parsing process, not for runtime data, it's + * better to use the more general representation.) + * + * Note that an integer-looking string will get lexed as T_Float if + * the value is too large to fit in a 'long'. *---------------------- */ typedef struct Value @@ -30,14 +45,13 @@ typedef struct Value NodeTag type; /* tag appropriately (eg. T_String) */ union ValUnion { + long ival; /* machine integer */ char *str; /* string */ - long ival; - double dval; } val; } Value; #define intVal(v) (((Value *)(v))->val.ival) -#define floatVal(v) (((Value *)(v))->val.dval) +#define floatVal(v) atof(((Value *)(v))->val.str) #define strVal(v) (((Value *)(v))->val.str) @@ -89,9 +103,9 @@ extern List *lconsi(int datum, List *list); extern bool member(void *datum, List *list); extern bool intMember(int datum, List *list); extern Value *makeInteger(long i); -extern Value *makeFloat(double d); +extern Value *makeFloat(char *numericStr); extern Value *makeString(char *str); -extern List *makeList(void *elem,...); +extern List *makeList(void *elem, ...); extern List *lappend(List *list, void *datum); extern List *lappendi(List *list, int datum); extern List *lremove(void *elem, List *list); |