argument of with_key doesn't parse correctly

[jeisner]

Syntactic bug in implementation of #29.
This works:

pathto(start) min= 0                     with_key [start].
pathto(V)     min= pathto(U) + edge(U,V) with_key [V | bestpath(U)].
bestpath(U) = $key(pathto(U)).

But this doesn't:

pathto(start) min= 0                     with_key [start].
pathto(V)     min= pathto(U) + edge(U,V) with_key [V | $key(pathto(U))].

In the second case, the second rule never seems to fire. It may be misparsing the | as "or" rather than list syntax. (To understand the message below, note that the vertices in this graph are 5-letter words such as "black" and "blank".)

Error(s) in rule: <repl>

    pathto(V)     min= pathto(U) + edge(U,V) with_key [V | $key(pathto(U))].

  TypeError:
    when `$key(pathto("black"))` = ["black"]


      pathto(V="blank") min= &with_key((pathto(U="black")=? + edge(U="black", V="blank")=10)=?, [(V="blank" | $key(&pathto(U="black"))=["black"])=?]).

[timvieira]

See also discussion on #15

[timvieira]

Btw, In the mean time you use single quotes '$key' to side-step the bug.

[jeisner]

See also discussion on #15

Ah yes, problem already reported and diagnosed there. But you closed that ticket so I guess the issue will live on here.

[nwf]

Er, wait, wasn't this fixed by ddb1042? Jason, can you tell me which version of dyna you're using? "(cd which dyna; git describe --always)" is probably the best way to do that right now.

[jeisner]

f4d6dd0