General Notes on Syntax

Keywords

Keywords

The following words are reserved by Scenic and cannot be used as identifiers (i.e. as names of variables, functions, classes, properties, etc.).

False       break       except      lambda      require 
None        by          finally     new         return  
True        class       for         nonlocal    to      
and         continue    from        not         try     
as          def         global      of          until   
assert      del         if          on          while   
async       do          import      or          with    
at          elif        in          pass        yield   
await       else        is          raise       

Soft Keywords

The following words have special meanings in Scenic in certain contexts, but are still available for use as identifiers. Users should take care not to use these names when doing so would introduce ambiguity. For example, consider the following code:

distance = 5  # not a good variable name to use here
new Object beyond A by distance from B

This might appear to use the three-argument form of the beyond specifier, creating the new object at distance 5 beyond A from the point of view of B. But in fact Scenic parses the code as beyond A by (distance from B), because the interpretation of distance as being part of the distance from operator takes precedence.

To avoid confusion, we recommend not using distance, angle, offset, altitude, or visible as identifiers in code that uses Scenic operators or specifiers (inside pure-Python helper functions is fine).

_               below           follow          not             simulation  
abort           beyond          following       of              simulator   
above           bottom          from            offset          steps       
additive        can             front           override        take        
after           case            heading         param           terminate   
ahead           choose          implies         past            top         
along           compose         initial         position        toward      
altitude        contained       interrupt       precondition    type        
always          deg             intersects      record          visible     
angle           directly        invariant       relative        wait        
apparent        distance        left            right           when        
apparently      dynamic         match           scenario        workspace   
away            ego             model           seconds         
back            eventually      monitor         see             
behavior        facing          mutate          setup           
behind          final           next            shuffle         

Builtin Names

The following names are built into Scenic and can be used but not overwritten .

float               globalParameters    int                 str