evaluator

package

v0.0.0-...-887f819 Latest Latest Go to latest Published: May 4, 2016 License: Apache-2.0 Imports: 19 Imported by: 0

Details

Valid go.mod file

The Go module system was introduced in Go 1.11 and is the official dependency management solution for Go.
Redistributable license

Redistributable licenses place minimal restrictions on how software can be used, modified, and redistributed.
Tagged version

Modules with tagged versions give importers more predictable builds.
Stable version

When a project reaches major version v1 it is considered stable.
Learn more about best practices

Repository

github.com/stormgbs/tidb

Links

Open Source Insights

Documentation ¶

Index ¶

Constants
Variables
func Eval(ctx context.Context, expr ast.ExprNode) (d types.Datum, err error)
func EvalBool(ctx context.Context, expr ast.ExprNode) (bool, error)
func EvalSubquery(ctx context.Context, v *ast.SubqueryExpr) error
func GetTimeValue(ctx context.Context, v interface{}, tp byte, fsp int) (types.Datum, error)
func IsCurrentTimeExpr(e ast.ExprNode) bool
type BuiltinFunc
type Evaluator
- func (e *Evaluator) Enter(in ast.Node) (out ast.Node, skipChildren bool)
- func (e *Evaluator) Leave(in ast.Node) (out ast.Node, ok bool)
type Func

Constants ¶

View Source

const (
	CodeInvalidOperation terror.ErrCode = 1
)

Error codes.

Variables ¶

View Source

var (
	// CurrentTimestamp is the keyword getting default value for datetime and timestamp type.
	CurrentTimestamp = "CURRENT_TIMESTAMP"

	// ZeroTimestamp shows the zero datetime and timestamp.
	ZeroTimestamp = "0000-00-00 00:00:00"
)

View Source

var (
	ErrInvalidOperation = terror.ClassEvaluator.New(CodeInvalidOperation, "invalid operation")
)

Error instances.

View Source

var Funcs = map[string]Func{

	"coalesce": {builtinCoalesce, 1, -1},
	"isnull":   {builtinIsNull, 1, 1},

	"abs":   {builtinAbs, 1, 1},
	"pow":   {builtinPow, 2, 2},
	"power": {builtinPow, 2, 2},
	"rand":  {builtinRand, 0, 1},

	"curdate":           {builtinCurrentDate, 0, 0},
	"current_date":      {builtinCurrentDate, 0, 0},
	"current_time":      {builtinCurrentTime, 0, 1},
	"current_timestamp": {builtinNow, 0, 1},
	"curtime":           {builtinCurrentTime, 0, 1},
	"date":              {builtinDate, 1, 1},
	"day":               {builtinDay, 1, 1},
	"dayname":           {builtinDayName, 1, 1},
	"dayofmonth":        {builtinDayOfMonth, 1, 1},
	"dayofweek":         {builtinDayOfWeek, 1, 1},
	"dayofyear":         {builtinDayOfYear, 1, 1},
	"hour":              {builtinHour, 1, 1},
	"microsecond":       {builtinMicroSecond, 1, 1},
	"minute":            {builtinMinute, 1, 1},
	"month":             {builtinMonth, 1, 1},
	"now":               {builtinNow, 0, 1},
	"second":            {builtinSecond, 1, 1},
	"sysdate":           {builtinSysDate, 0, 1},
	"utc_date":          {builtinUTCDate, 0, 0},
	"week":              {builtinWeek, 1, 2},
	"weekday":           {builtinWeekDay, 1, 1},
	"weekofyear":        {builtinWeekOfYear, 1, 1},
	"year":              {builtinYear, 1, 1},
	"yearweek":          {builtinYearWeek, 1, 2},
	"extract":           {builtinExtract, 2, 2},
	"date_arith":        {builtinDateArith, 3, 3},

	"ascii":           {builtinASCII, 1, 1},
	"concat":          {builtinConcat, 1, -1},
	"concat_ws":       {builtinConcatWS, 2, -1},
	"left":            {builtinLeft, 2, 2},
	"length":          {builtinLength, 1, 1},
	"lower":           {builtinLower, 1, 1},
	"lcase":           {builtinLower, 1, 1},
	"ltrim":           {trimFn(strings.TrimLeft, spaceChars), 1, 1},
	"repeat":          {builtinRepeat, 2, 2},
	"upper":           {builtinUpper, 1, 1},
	"ucase":           {builtinUpper, 1, 1},
	"replace":         {builtinReplace, 3, 3},
	"rtrim":           {trimFn(strings.TrimRight, spaceChars), 1, 1},
	"strcmp":          {builtinStrcmp, 2, 2},
	"convert":         {builtinConvert, 2, 2},
	"substring":       {builtinSubstring, 2, 3},
	"substring_index": {builtinSubstringIndex, 3, 3},
	"locate":          {builtinLocate, 2, 3},
	"trim":            {builtinTrim, 1, 3},

	"current_user":  {builtinCurrentUser, 0, 0},
	"database":      {builtinDatabase, 0, 0},
	"found_rows":    {builtinFoundRows, 0, 0},
	"user":          {builtinUser, 0, 0},
	"connection_id": {builtinConnectionID, 0, 0},
	"version":       {builtinVersion, 0, 0},

	"if":     {builtinIf, 3, 3},
	"ifnull": {builtinIfNull, 2, 2},
	"nullif": {builtinNullIf, 2, 2},
}

Funcs holds all registered builtin functions.

Functions ¶

func Eval ¶

func Eval(ctx context.Context, expr ast.ExprNode) (d types.Datum, err error)

Eval evaluates an expression to a datum.

func EvalBool ¶

func EvalBool(ctx context.Context, expr ast.ExprNode) (bool, error)

EvalBool evalueates an expression to a boolean value.

func EvalSubquery ¶

func EvalSubquery(ctx context.Context, v *ast.SubqueryExpr) error

EvalSubquery evaluates a subquery.

func GetTimeValue ¶

func GetTimeValue(ctx context.Context, v interface{}, tp byte, fsp int) (types.Datum, error)

GetTimeValue gets the time value with type tp.

func IsCurrentTimeExpr ¶

func IsCurrentTimeExpr(e ast.ExprNode) bool

IsCurrentTimeExpr returns whether e is CurrentTimeExpr.

Types ¶

type BuiltinFunc ¶

type BuiltinFunc func([]types.Datum, context.Context) (types.Datum, error)

BuiltinFunc is the function signature for builtin functions

type Evaluator ¶

type Evaluator struct {
	// contains filtered or unexported fields
}

Evaluator is an ast Visitor that evaluates an expression.

func (*Evaluator) Enter ¶

func (e *Evaluator) Enter(in ast.Node) (out ast.Node, skipChildren bool)

Enter implements ast.Visitor interface.

func (*Evaluator) Leave ¶

func (e *Evaluator) Leave(in ast.Node) (out ast.Node, ok bool)

Leave implements ast.Visitor interface.

type Func ¶

type Func struct {
	// F is the specific calling function.
	F BuiltinFunc
	// MinArgs is the minimal arguments needed,
	MinArgs int
	// MaxArgs is the maximal arguments needed, -1 for infinity.
	MaxArgs int
}

Func is for a builtin function.

Source Files ¶

View all Source files

?	: This menu
/	: Search site
f or F	: Jump to
y or Y	: Canonical URL