[erlang-questions] how: to construct and evaluate qlc expressions dynamically
Rick Pettit
rpettit@REDACTED
Mon Dec 17 23:21:17 CET 2007
I am trying to write a function which takes as input a table name and a
list of query constraints in the form of triplets (column id, operator, value)
which returns a fun wrapping the equivalent qlc expression.
For example:
QLCFun = generate_qlc_fun("favorites",[{"flavor","==","chocolate"},
{"number","<=","3"}]).
QLCFun should be roughly equivalent to:
qlc:q([X || X <- mnesia:table(favorites),
X#favorites.flavor == "chocolate",
X#favorites.number <= 3]).
So far I've stumbled across the erl_syntax manpage and functions:
list_comp_template/1
list_comp_body/1
list_comp/2
Am I in the ballpark, or is there a better way to do this?
Anyone know of a place where a beginner (to dynamic generation and evaluation
of erlang code) can find decent sample code?
-Rick
More information about the erlang-questions
mailing list