parse_coerce.h

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/*-------------------------------------------------------------------------
 *
 * parse_coerce.h
 *  Routines for type coercion.
 *
 *
 * Portions Copyright (c) 1996-2017, 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, Oid *input_typeids, 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,
                 CoercionForm cformat, int location,
                 bool hideInputCoercion,
                 bool lengthCoercionDone);

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(Oid *actual_arg_types,
                               Oid *declared_arg_types,
                               int nargs);
extern Oid enforce_generic_type_consistency(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 */