🦡

Possum

a tiny stack-based critter language — forage, climb, hiss

program.possum Ctrl+Enter to run
Output 

          

        


        

          
Field Guide — the Possum vocabulary

          

            
Programs are words separated by whitespace. Numbers are pushed onto a stack; words pull values off it and push results back. # starts a comment.


            
Stack

            
    
              
  • climb — duplicate the top value
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  • scram — drop the top value
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  • waddle — swap the top two
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  • peek — copy the 2nd value to the top
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  • tumble — rotate the top three
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Maths & logic

            
    
              
  • + - * / % — arithmetic on the top two
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  • < > = <= >= != — compare, push 1 (true) or 0 (false)
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  • and or not — logic (nonzero is true)
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Pouches (variables)

            
    
              
  • pouch name — pop the top, stash it in name
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  • grab name — push the value stashed in name
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Noises (output)

            
    
              
  • hiss — pop and print as a number
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  • screech — pop and print as an ASCII character
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  • say "text" — print a literal string
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Control flow

            
    
              
  • if … end / if … else … end — pops a condition
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  • times … end — pop N, repeat the body N times; count is the 0-based index
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  • while … do … end — repeat while the condition block leaves a nonzero value
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