Package io.permazen.parse.func

Interface Function

All Known Implementing Classes:

AbstractFunction, AllFunction, ConcatFunction, CountFunction, CreateFunction, DumpFunction, LimitFunction, ListFunction, PrintFunction, QueryCompositeIndexFunction, QueryIndexFunction, QueryListElementIndexFunction, QueryMapValueIndexFunction, QueryVersionFunction, SessionFunction, SimpleCliFunction, SimpleFunction, UpgradeFunction, VersionFunction

public interface Function

Function hook in a ParseSession.

See Also:

AbstractFunction, SimpleFunction

Method Summary

Modifier and Type	Method	Description
Value	apply(ParseSession session, Object params)	Evaluate this function.
String	getHelpDetail()	Get expanded help (typically multiple lines).
String	getHelpSummary()	Get summarized help (typically a single line).
String	getName()	Get the name of this function.
EnumSet<SessionMode>	getSessionModes()	Get the SessionMode(s) supported by this function.
String	getUsage()	Get function usage string.
Object	parseParams(ParseSession session, ParseContext ctx, boolean complete)	Parse function parameters.

Method Detail

getName

String getName()

Get the name of this function.

Returns:

function name

getUsage

String getUsage()

Get function usage string. For example: pow(base, exponent).

Returns:

function usage string

getHelpSummary

String getHelpSummary()

Get summarized help (typically a single line).

Returns:

one line summarized description of this function

getHelpDetail

String getHelpDetail()

Get expanded help (typically multiple lines). May refer to the usage string.

The implementation in AbstractFunction delegates to getHelpSummary().

Returns:

detailed description of this function

getSessionModes

EnumSet<SessionMode> getSessionModes()

Get the SessionMode(s) supported by this function.

Returns:

set of supported SessionModes

parseParams

Object parseParams(ParseSession session,
                   ParseContext ctx,
                   boolean complete)

Parse function parameters.

The ctx will be pointing at the first parameter (if any) or closing parenthesis. This method should parse (but not evaluate) function parameters up through the closing parenthesis. The return value is an opaque value representing the parsed parameters and subsequently passed to apply().

Parameters:

session - parse session

ctx - parse context

complete - false if parse is "for real", true if only for tab completion calculation

Returns:

parsed parameters object to be passed to apply()

Throws:

ParseException - if parse fails, or if complete is true and there are valid completions

apply

Value apply(ParseSession session,
            Object params)

Evaluate this function. There will be a transaction open.

Parameters:

session - parse session

params - parsed parameters returned by parseParams()

Returns:

value returned by this function

Throws:

RuntimeException - if there is an error