| /*------------------------------------------------------------------------- |
| * |
| * value.h |
| * interface for Value nodes |
| * |
| * |
| * Copyright (c) 2003-2009, PostgreSQL Global Development Group |
| * |
| * $PostgreSQL: pgsql/src/include/nodes/value.h,v 1.5 2006/03/05 15:58:57 momjian Exp $ |
| * |
| *------------------------------------------------------------------------- |
| */ |
| |
| #ifndef VALUE_H |
| #define VALUE_H |
| |
| #include "nodes/nodes.h" |
| |
| /*---------------------- |
| * Value node |
| * |
| * The same Value struct is used for five node types: T_Integer, |
| * T_Float, T_String, T_BitString, T_Null. |
| * |
| * 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'. |
| * |
| * Nulls, of course, don't need the value part at all. |
| *---------------------- |
| */ |
| typedef struct Value |
| { |
| NodeTag type; /* tag appropriately (eg. T_String) */ |
| union ValUnion |
| { |
| long ival; /* machine integer */ |
| char *str; /* string */ |
| } val; |
| } Value; |
| |
| #define intVal(v) (((Value *)(v))->val.ival) |
| #define floatVal(v) atof(((Value *)(v))->val.str) |
| #define strVal(v) (((Value *)(v))->val.str) |
| |
| extern Value *makeInteger(long i); |
| extern Value *makeFloat(char *numericStr); |
| extern Value *makeString(char *str); |
| extern Value *makeNullString(void); |
| extern Value *makeBitString(char *str); |
| |
| #endif /* VALUE_H */ |