AspectedRouting/Profiles/Format.md

Functions

• $funcName indicates a builtin function
• #parameter indicates a configurable parameter

A profile is a function which maps a set of tags onto a value. It is basically Haskell, except that functions can have multiple types. During typechecking, some types will turn out not to be possible and they will dissappear, potentially fixing the implementation of the function itself.

Injected tags

Aspects can use the following (extra) tags:

• _direction is the value to indicate if the traveller goes forward or backwards. It is not available when calculating the 'oneway' field
• access will become the value calculated in the field access (not available to calculate access)
• oneway will become the value calculated in the field oneway (not available to calculate access and speed)

Vehicle.json

• Metdata: these tags will be copied to the routerdb, but can not be used for routeplanning. A prime example is name (the streetname), as it is useful for routeplanning but very useful for navigation afterwards

• vehicletypes: used for turn restrictions, legacy for use with itinero 1.0

• defaults: a dictionary of {"#paramName": "value"}, used in determining the weight of an edge. note: the # has to be included

• access is a field in the vehicle file. It should be an expression returning a string. If (and only if) this string is no, the way will be marked as not accessible and no more values will be calculated. All other values are regarded as being accessible. When calculated, the tag access with the calculated value is written into the tag table or the other aspects to use.

• oneway is a field in the vehicle file. It should be an expression returning both, with or against. When calculated, the tag oneway is added to the tags for the other aspects to be calculated.

• speed: an expression indicating how fast the vehicle can go there. It should take into account legal, practical and social aspects. An example expression could be {"$min", ["$legal_maxspeed", "#defaultspeed"]}

• priorities: a table of {'#paramName', expression} determining the priority (1/cost) of a way, per meter. The formula used is paramName * expression + paramName0 * expression0 + ... (speed, access and oneway can be used here as tags indicate the earlier defined respective aspects). Use a weight == 1 to get the shortest route or $speed to get the fastest route

Calculating oneway and forward/backward speeds

There are two possibilities in order to calculate the possible direction of a traveller can go over an edge:

1. This can be indicated explicitely with the 'oneway'-field. If this expression returns both, the edge is traversable in two directions. If it is either with or against, then it is not
2. This can be indicated with having a speed or factor which is equal to (or smaller then) 0, in conjunction with a _direction=with or _direction=against tag. Bicycle lanes are an excellent example for this: a cycleway:right=yes; cycleway:left=no, the speed and factor for _direction=with could be far greater then for _direction=against

Note that _direction=with and _direction=against are not supported in Itinero1.0 profiles. For maximal compatibility and programming comfort, a mixture of both techniques should be used. For example, one aspect interpreting the legal onewayness in tandem with one aspect determining comfort by direction is optimal.

Pitfalls

"$all" should not be used together with a mapping: it checks if all present keys return true or yes (or some other value); it does not check that all the specified keys in the mapping are present.

For this, an additional 'mustHaveKeys' should be added added