Condition, PatternTest, Alternatives

[anandijain]

these should be the next Pattern objects to handle
i think alternatives is easy. It should be as simple as iterating the arguments to Alternatives head calling match on each one

Condition im less sure about bc of f[x_] := ppp[x] /; x > 0 giving

Hold[SetDelayed[f[Pattern[x, Blank[]]], Condition[ppp[x], Greater[x, 0]]]] 

Where the Condition does not wrap the Pattern. I think that means you see the match but in the evaluator or wherever the rule application is, you then need to check the head of the rhs to see if its a condition and bail if its not True

in order of importance, Condition is clearly the most useful

PatternTest is lowest priority I think

I want Condition support so that I could write

In[59]:= MatchQ[{a,b,c},{elems__} /; SameQ @@ (Head /@ {elems})]

Out[59]= True

In[60]:= MatchQ[{a,b,c[d]},{elems__} /; SameQ @@ (Head /@ {elems})]

Out[60]= False