com.akiban.sql.compiler
Class TypeCompiler

java.lang.Object
  com.akiban.sql.compiler.TypeCompiler

Direct Known Subclasses:

BitTypeCompiler, BooleanTypeCompiler, CharTypeCompiler, CLOBTypeCompiler, DateTypeCompiler, IntervalTypeCompiler, LOBTypeCompiler, NumericTypeCompiler, RefTypeCompiler, TimestampTypeCompiler, TimeTypeCompiler, UserDefinedTypeCompiler, XMLTypeCompiler

public abstract class TypeCompiler
extends Object

This interface defines methods associated with a TypeId that are used by the compiler.

Field Summary

static String	AVG_OP
static int	BOOLEAN_MAXWIDTH_AS_CHAR
static String	DIV_OP
static String	DIVIDE_OP
static int	DOUBLE_MAXWIDTH_AS_CHAR
static int	INT_MAXWIDTH_AS_CHAR
static int	LONGINT_MAXWIDTH_AS_CHAR Various fixed numbers related to datatypes.
static String	MINUS_OP
static String	MOD_OP
static String	PLUS_OP
static int	REAL_MAXWIDTH_AS_CHAR
static int	SMALLINT_MAXWIDTH_AS_CHAR
static String	SUM_OP
static String	TIMES_OP
static int	TINYINT_MAXWIDTH_AS_CHAR

Constructor Summary

protected

TypeCompiler(TypeId typeId)

Method Summary

abstract boolean	compatible(TypeId otherType) Determine if this type is compatible to some other type (e.g.
abstract boolean	convertible(TypeId otherType, boolean forDataTypeFunction) Determine if this type can be CONVERTed to some other type
abstract int	getCastToCharWidth(DataTypeDescriptor dtd) Return the maximum width for this data type when cast to a char type.
abstract String	getCorrespondingPrimitiveTypeName() Get the name of the corresponding Java type.
abstract String	getPrimitiveMethodName() Get the method name for getting out the corresponding primitive Java type from a DataValueDescriptor.
protected int	getStoredFormatIdFromTypeId() Get the format id from the corresponding TypeId.
static TypeCompiler	getTypeCompiler(TypeId typeId) Get the TypeCompiler that corresponds to the given TypeId.
TypeId	getTypeId()
protected boolean	numberConvertible(TypeId otherType, boolean forDataTypeFunction) Tell whether this numeric type can be converted to the given type.
DataTypeDescriptor	resolveArithmeticOperation(DataTypeDescriptor leftType, DataTypeDescriptor rightType, String operator) Type resolution methods on binary operators

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LONGINT_MAXWIDTH_AS_CHAR

public static final int LONGINT_MAXWIDTH_AS_CHAR

Various fixed numbers related to datatypes.

See Also:

Constant Field Values

INT_MAXWIDTH_AS_CHAR

public static final int INT_MAXWIDTH_AS_CHAR

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Constant Field Values

SMALLINT_MAXWIDTH_AS_CHAR

public static final int SMALLINT_MAXWIDTH_AS_CHAR

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Constant Field Values

TINYINT_MAXWIDTH_AS_CHAR

public static final int TINYINT_MAXWIDTH_AS_CHAR

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Constant Field Values

DOUBLE_MAXWIDTH_AS_CHAR

public static final int DOUBLE_MAXWIDTH_AS_CHAR

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Constant Field Values

REAL_MAXWIDTH_AS_CHAR

public static final int REAL_MAXWIDTH_AS_CHAR

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Constant Field Values

BOOLEAN_MAXWIDTH_AS_CHAR

public static final int BOOLEAN_MAXWIDTH_AS_CHAR

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Constant Field Values

PLUS_OP

public static final String PLUS_OP

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Constant Field Values

DIVIDE_OP

public static final String DIVIDE_OP

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Constant Field Values

DIV_OP

public static final String DIV_OP

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Constant Field Values

MINUS_OP

public static final String MINUS_OP

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Constant Field Values

TIMES_OP

public static final String TIMES_OP

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Constant Field Values

SUM_OP

public static final String SUM_OP

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Constant Field Values

AVG_OP

public static final String AVG_OP

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Constant Field Values

MOD_OP

public static final String MOD_OP

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Constant Field Values

Constructor Detail

TypeCompiler

protected TypeCompiler(TypeId typeId)

Method Detail

getTypeId

public TypeId getTypeId()

resolveArithmeticOperation

public DataTypeDescriptor resolveArithmeticOperation(DataTypeDescriptor leftType,
                                                     DataTypeDescriptor rightType,
                                                     String operator)
                                              throws StandardException

Type resolution methods on binary operators

Parameters:

leftType - The type of the left parameter

rightType - The type of the right parameter

operator - The name of the operator (e.g. "+").

Returns:

The type of the result

Throws:

StandardException - Thrown on error

convertible

public abstract boolean convertible(TypeId otherType,
                                    boolean forDataTypeFunction)

Determine if this type can be CONVERTed to some other type

Parameters:

otherType - The CompilationType of the other type to compare this type to

forDataTypeFunction - true if this is a type function that requires more liberal behavior (e.g DOUBLE can convert a char but you cannot cast a CHAR to double.

Returns:

true if the types can be converted, false if conversion is not allowed

numberConvertible

protected boolean numberConvertible(TypeId otherType,
                                    boolean forDataTypeFunction)

Tell whether this numeric type can be converted to the given type.

Parameters:

otherType - The TypeId of the other type.

forDataTypeFunction - was this called from a scalarFunction like CHAR() or DOUBLE()

compatible

public abstract boolean compatible(TypeId otherType)

Determine if this type is compatible to some other type (e.g. COALESCE(thistype, othertype)).

Parameters:

otherType - The CompilationType of the other type to compare this type to

Returns:

true if the types are compatible, false if not compatible

getCorrespondingPrimitiveTypeName

public abstract String getCorrespondingPrimitiveTypeName()

Get the name of the corresponding Java type. For numerics and booleans we will get the corresponding Java primitive type. e Each SQL type has a corresponding Java type. When a SQL value is passed to a Java method, it is translated to its corresponding Java type. For example, a SQL Integer will be mapped to a Java int, but a SQL date will be mapped to a java.sql.Date.

Returns:

The name of the corresponding Java primitive type.

getPrimitiveMethodName

public abstract String getPrimitiveMethodName()

Get the method name for getting out the corresponding primitive Java type from a DataValueDescriptor.

Returns:

String The method call name for getting the corresponding primitive Java type.

getCastToCharWidth

public abstract int getCastToCharWidth(DataTypeDescriptor dtd)

Return the maximum width for this data type when cast to a char type.

Parameters:

dtd - The associated DataTypeDescriptor for this TypeId.

Returns:

int The maximum width for this data type when cast to a char type.

getStoredFormatIdFromTypeId

protected int getStoredFormatIdFromTypeId()

Get the format id from the corresponding TypeId.

Returns:

The format from the corresponding TypeId.

See Also:

TypeId.FormatIds

getTypeCompiler

public static TypeCompiler getTypeCompiler(TypeId typeId)

Get the TypeCompiler that corresponds to the given TypeId.