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https://github.com/postgres/postgres.git
synced 2026-06-01 21:39:18 -04:00
Tom Lane
b310b6e31c
All expression nodes now have an explicit output-collation field, unless they are known to only return a noncollatable data type (such as boolean or record). Also, nodes that can invoke collation-aware functions store a separate field that is the collation value to pass to the function. This avoids confusion that arises when a function has collatable inputs and noncollatable output type, or vice versa. Also, replace the parser's on-the-fly collation assignment method with a post-pass over the completed expression tree. This allows us to use a more complex (and hopefully more nearly spec-compliant) assignment rule without paying for it in extra storage in every expression node. Fix assorted bugs in the planner's handling of collations by making collation one of the defining properties of an EquivalenceClass and by converting CollateExprs into discardable RelabelType nodes during expression preprocessing.
91 lines
3.0 KiB
C
91 lines
3.0 KiB
C
/*-------------------------------------------------------------------------
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*
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* parse_coerce.h
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* Routines for type coercion.
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*
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*
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* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* src/include/parser/parse_coerce.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef PARSE_COERCE_H
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#define PARSE_COERCE_H
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#include "parser/parse_node.h"
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/* Type categories (see TYPCATEGORY_xxx symbols in catalog/pg_type.h) */
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typedef char TYPCATEGORY;
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/* Result codes for find_coercion_pathway */
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typedef enum CoercionPathType
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{
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COERCION_PATH_NONE, /* failed to find any coercion pathway */
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COERCION_PATH_FUNC, /* apply the specified coercion function */
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COERCION_PATH_RELABELTYPE, /* binary-compatible cast, no function */
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COERCION_PATH_ARRAYCOERCE, /* need an ArrayCoerceExpr node */
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COERCION_PATH_COERCEVIAIO /* need a CoerceViaIO node */
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} CoercionPathType;
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extern bool IsBinaryCoercible(Oid srctype, Oid targettype);
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extern bool IsPreferredType(TYPCATEGORY category, Oid type);
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extern TYPCATEGORY TypeCategory(Oid type);
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extern Node *coerce_to_target_type(ParseState *pstate,
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Node *expr, Oid exprtype,
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Oid targettype, int32 targettypmod,
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CoercionContext ccontext,
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CoercionForm cformat,
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int location);
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extern bool can_coerce_type(int nargs, Oid *input_typeids, Oid *target_typeids,
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CoercionContext ccontext);
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extern Node *coerce_type(ParseState *pstate, Node *node,
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Oid inputTypeId, Oid targetTypeId, int32 targetTypeMod,
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CoercionContext ccontext, CoercionForm cformat, int location);
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extern Node *coerce_to_domain(Node *arg, Oid baseTypeId, int32 baseTypeMod,
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Oid typeId,
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CoercionForm cformat, int location,
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bool hideInputCoercion,
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bool lengthCoercionDone);
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extern Node *coerce_to_boolean(ParseState *pstate, Node *node,
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const char *constructName);
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extern Node *coerce_to_specific_type(ParseState *pstate, Node *node,
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Oid targetTypeId,
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const char *constructName);
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extern int parser_coercion_errposition(ParseState *pstate,
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int coerce_location,
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Node *input_expr);
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extern Oid select_common_type(ParseState *pstate, List *exprs,
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const char *context, Node **which_expr);
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extern Node *coerce_to_common_type(ParseState *pstate, Node *node,
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Oid targetTypeId,
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const char *context);
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extern bool check_generic_type_consistency(Oid *actual_arg_types,
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Oid *declared_arg_types,
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int nargs);
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extern Oid enforce_generic_type_consistency(Oid *actual_arg_types,
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Oid *declared_arg_types,
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int nargs,
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Oid rettype,
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bool allow_poly);
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extern Oid resolve_generic_type(Oid declared_type,
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Oid context_actual_type,
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Oid context_declared_type);
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extern CoercionPathType find_coercion_pathway(Oid targetTypeId,
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Oid sourceTypeId,
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CoercionContext ccontext,
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Oid *funcid);
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extern CoercionPathType find_typmod_coercion_function(Oid typeId,
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Oid *funcid);
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#endif /* PARSE_COERCE_H */
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