com.ur.urcap.api.domain.value.expression

Interface ExpressionBuilder

public interface ExpressionBuilder

This interface provides methods to build a single expression consisting of PolyScope entities, such as variables, Features, I/Os and/or waypoints, as well as string parts. Each expression being built must use a new ExpressionBuilder instance.

To build an expression looking like, e.g. 'var_1 + var_2 + 5', use the following code snippet:

 
 Expression expr = builder.appendVariable(var_1)
                          .append(" + ")
                          .appendVariable(var_2)
                          .append(" + 5")
                          .build();
 
 

The expression built will have information about the entities and their type (in the example the variables 'var_1' and 'var_2'). Should the entities for some reason not be present, the expression can still be valid but will be undefined. This can be the case for, e.g. installation variables, if a different installation is loaded or the end user has deleted the variable. When the variable is present again, the expression will become defined.

Method Summary

Modifier and Type	Method and Description
ExpressionBuilder	append(String expressionPart) Append a string part of the expression.
ExpressionBuilder	appendFeature(Feature feature) Append a Feature object to the expression.
ExpressionBuilder	appendIO(IO io) Append an I/O object to the expression.
ExpressionBuilder	appendVariable(Variable variable) Append a variable object to the expression.
ExpressionBuilder	appendWaypoint(WaypointNode waypoint) Append a waypoint to the expression.
Expression	build() Build the expression consisting of all the appended parts.

Method Detail

append

ExpressionBuilder append(String expressionPart)

Append a string part of the expression. This can be anything that is valid in an expression or even the full expression if it does not contain references to any entities (such as variables and features among others).

Parameters:

expressionPart - the expression part to be appended.

Returns:

the ExpressionBuilder

appendVariable

ExpressionBuilder appendVariable(Variable variable)

Append a variable object to the expression.

Parameters:

variable - the variable to append.

Returns:

the ExpressionBuilder

appendFeature

ExpressionBuilder appendFeature(Feature feature)

Append a Feature object to the expression. When this part is evaluated the pose of the Feature is used.

Parameters:

feature - the Feature to append

Returns:

the ExpressionBuilder

appendWaypoint

ExpressionBuilder appendWaypoint(WaypointNode waypoint)

Append a waypoint to the expression. When this part is evaluated the pose of the waypoint is used.

Parameters:

waypoint - the waypoint to append

Returns:

the ExpressionBuilder

appendIO

ExpressionBuilder appendIO(IO io)

Append an I/O object to the expression.

Parameters:

io - the I/O to append.

Returns:

the ExpressionBuilder

build

Expression build()
          throws InvalidExpressionException

Build the expression consisting of all the appended parts.

Returns:

the expression

Throws:

InvalidExpressionException - if the expression is syntactically incorrect/invalid.