parse_coerce.h

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/*-------------------------------------------------------------------------
 *
 * parse_coerce.h
 *  Routines for type coercion.
 *
 *
 * Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/parser/parse_coerce.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef PARSE_COERCE_H
#define PARSE_COERCE_H

#include "parser/parse_node.h"


/* Type categories (see TYPCATEGORY_xxx symbols in catalog/pg_type.h) */
typedef char TYPCATEGORY;

/* Result codes for find_coercion_pathway */
typedef enum CoercionPathType
{
    COERCION_PATH_NONE,         /* failed to find any coercion pathway */
    COERCION_PATH_FUNC,         /* apply the specified coercion function */
    COERCION_PATH_RELABELTYPE,  /* binary-compatible cast, no function */
    COERCION_PATH_ARRAYCOERCE,  /* need an ArrayCoerceExpr node */
    COERCION_PATH_COERCEVIAIO   /* need a CoerceViaIO node */
} CoercionPathType;


extern bool IsBinaryCoercible(Oid srctype, Oid targettype);
extern bool IsPreferredType(TYPCATEGORY category, Oid type);
extern TYPCATEGORY TypeCategory(Oid type);

extern Node *coerce_to_target_type(ParseState *pstate,
                                   Node *expr, Oid exprtype,
                                   Oid targettype, int32 targettypmod,
                                   CoercionContext ccontext,
                                   CoercionForm cformat,
                                   int location);
extern bool can_coerce_type(int nargs, const Oid *input_typeids, const Oid *target_typeids,
                            CoercionContext ccontext);
extern Node *coerce_type(ParseState *pstate, Node *node,
                         Oid inputTypeId, Oid targetTypeId, int32 targetTypeMod,
                         CoercionContext ccontext, CoercionForm cformat, int location);
extern Node *coerce_to_domain(Node *arg, Oid baseTypeId, int32 baseTypeMod,
                              Oid typeId,
                              CoercionContext ccontext, CoercionForm cformat, int location,
                              bool hideInputCoercion);

extern Node *coerce_to_boolean(ParseState *pstate, Node *node,
                               const char *constructName);
extern Node *coerce_to_specific_type(ParseState *pstate, Node *node,
                                     Oid targetTypeId,
                                     const char *constructName);

extern Node *coerce_to_specific_type_typmod(ParseState *pstate, Node *node,
                                            Oid targetTypeId, int32 targetTypmod,
                                            const char *constructName);

extern int  parser_coercion_errposition(ParseState *pstate,
                                        int coerce_location,
                                        Node *input_expr);

extern Oid  select_common_type(ParseState *pstate, List *exprs,
                               const char *context, Node **which_expr);
extern Node *coerce_to_common_type(ParseState *pstate, Node *node,
                                   Oid targetTypeId,
                                   const char *context);

extern bool check_generic_type_consistency(const Oid *actual_arg_types,
                                           const Oid *declared_arg_types,
                                           int nargs);
extern Oid  enforce_generic_type_consistency(const Oid *actual_arg_types,
                                             Oid *declared_arg_types,
                                             int nargs,
                                             Oid rettype,
                                             bool allow_poly);
extern Oid  resolve_generic_type(Oid declared_type,
                                 Oid context_actual_type,
                                 Oid context_declared_type);

extern CoercionPathType find_coercion_pathway(Oid targetTypeId,
                                              Oid sourceTypeId,
                                              CoercionContext ccontext,
                                              Oid *funcid);
extern CoercionPathType find_typmod_coercion_function(Oid typeId,
                                                      Oid *funcid);

#endif                          /* PARSE_COERCE_H */