commands mq and tq can take a tree with metas to guide generation

src/runtime/haskell/PGF.hs

@@ -79,6 +79,7 @@ module PGF(
 
            -- ** Generation
            generateRandom, generateAll, generateAllDepth,
+           generateRandomFrom, -- from initial expression, possibly weighed
 
            -- ** Morphological Analysis
            Lemma, Analysis, Morpho,

src/runtime/haskell/PGF/Generate.hs

@@ -21,6 +21,10 @@ generateRandomFrom mex ps rg pgf ty =
   maybe (gen ty) (generateForMetas pgf gen) mex where
     gen ty = genRandomProb ps rg pgf ty
 
+
+-- generic algorithm for filling holes in a generator
+---- for random, should be breadth-first, since now the first metas always get the same
+---- value when a list is generated
 generateForMetas :: PGF -> (Type -> [Expr]) -> Expr -> [Expr]
 generateForMetas pgf gen exp = case exp of
   EApp f (EMeta _) -> [EApp g a | g <- gener f, a <- genArg g]