value.h

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/*-------------------------------------------------------------------------
 *
 * value.h
 *    interface for value nodes
 *
 *
 * Copyright (c) 2003-2024, PostgreSQL Global Development Group
 *
 * src/include/nodes/value.h
 *
 *-------------------------------------------------------------------------
 */
 
#ifndef VALUE_H
#define VALUE_H
 
#include "nodes/nodes.h"
 
/*
 * The node types Integer, Float, String, and BitString are used to represent
 * literals in the lexer and are also used to pass constants around in the
 * parser.  One difference between these node types and, say, a plain int or
 * char * is that the nodes can be put into a List.
 *
 * (There used to be a Value node, which encompassed all these different node types.  Hence the name of this file.)
 */
 
typedef struct Integer
{
    pg_node_attr(special_read_write)
 
    NodeTag     type;
    int         ival;
} Integer;
 
/*
 * Float is internally represented as string.  Using T_Float as the node type
 * simply indicates that the contents of the string look like a valid numeric
 * literal.  The value might end up being converted to NUMERIC, so we can't
 * store it internally as a C double, since that could lose precision.  Since
 * these nodes are generally 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 an 'int'.
 */
typedef struct Float
{
    pg_node_attr(special_read_write)
 
    NodeTag     type;
    char       *fval;
} Float;
 
typedef struct Boolean
{
    pg_node_attr(special_read_write)
 
    NodeTag     type;
    bool        boolval;
} Boolean;
 
typedef struct String
{
    pg_node_attr(special_read_write)
 
    NodeTag     type;
    char       *sval;
} String;
 
typedef struct BitString
{
    pg_node_attr(special_read_write)
 
    NodeTag     type;
    char       *bsval;
} BitString;
 
#define intVal(v)       (castNode(Integer, v)->ival)
#define floatVal(v)     atof(castNode(Float, v)->fval)
#define boolVal(v)      (castNode(Boolean, v)->boolval)
#define strVal(v)       (castNode(String, v)->sval)
 
extern Integer *makeInteger(int i);
extern Float *makeFloat(char *numericStr);
extern Boolean *makeBoolean(bool val);
extern String *makeString(char *str);
extern BitString *makeBitString(char *str);
 
#endif                          /* VALUE_H */