Class JavascriptCompiler

An expression compiler for javascript expressions.

Inheritance

object

JavascriptCompiler

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Expressions.JS

Assembly: Lucene.Net.Expressions.dll

Syntax

public class JavascriptCompiler

Remarks

An expression compiler for javascript expressions.

Example:

Expression foo = JavascriptCompiler.Compile("((0.3*popularity)/10.0)+(0.7*score)");

See the package documentation for the supported syntax and default functions.

You can compile with an alternate set of functions via Compile(string, IDictionary<string, MethodInfo>). For example:

// instantiate and add all the default functions
IDictionary<string, MethodInfo> functions = new Dictionary<string, MethodInfo>(JavascriptCompiler.DEFAULT_FUNCTIONS);
// add sqrt()
functions["sqrt"] = (typeof(Math)).GetMethod("Sqrt", new Type[] { typeof(double) });
// call compile with customized function map
Expression foo = JavascriptCompiler.Compile("sqrt(score)+ln(popularity)", functions);

Note

This API is experimental and might change in incompatible ways in the next release.

Fields

DEFAULT_FUNCTIONS

The default set of functions available to expressions.

Declaration

public static readonly IDictionary<string, MethodInfo> DEFAULT_FUNCTIONS

Field Value

Type	Description
IDictionary<string, MethodInfo>

Remarks

The default set of functions available to expressions.

See the package documentation for a list.

Methods

Compile(string)

Compiles the given expression.

Declaration

public static Expression Compile(string sourceText)

Parameters

Type	Name	Description
string	sourceText	The expression to compile

Returns

Type	Description
Expression	A new compiled expression

Remarks

An expression compiler for javascript expressions.

Example:

Expression foo = JavascriptCompiler.Compile("((0.3*popularity)/10.0)+(0.7*score)");

See the package documentation for the supported syntax and default functions.

You can compile with an alternate set of functions via Compile(string, IDictionary<string, MethodInfo>). For example:

// instantiate and add all the default functions
IDictionary<string, MethodInfo> functions = new Dictionary<string, MethodInfo>(JavascriptCompiler.DEFAULT_FUNCTIONS);
// add sqrt()
functions["sqrt"] = (typeof(Math)).GetMethod("Sqrt", new Type[] { typeof(double) });
// call compile with customized function map
Expression foo = JavascriptCompiler.Compile("sqrt(score)+ln(popularity)", functions);

Note

This API is experimental and might change in incompatible ways in the next release.

Exceptions

Type	Condition
ParseException	on failure to compile

Compile(string, IDictionary<string, MethodInfo>)

Compiles the given expression with the supplied custom functions.

Declaration

public static Expression Compile(string sourceText, IDictionary<string, MethodInfo> functions)

Parameters

Type	Name	Description
string	sourceText	The expression to compile
IDictionary<string, MethodInfo>	functions	map of string names to functions

Returns

Type	Description
Expression	A new compiled expression

Remarks

Compiles the given expression with the supplied custom functions.

Functions must be public static, return double and can take from zero to 256 double parameters.

Exceptions

Type	Condition
ParseException	on failure to compile