Agda.TypeChecking.DisplayForm

Documentation

displayForm :: QName -> Args -> TCM (Maybe DisplayTerm)

Find a matching display form for q vs. In essence this tries to reqwrite q vs with any display form q ps --> dt and returns the instantiated dt if successful. First match wins.

matchDisplayForm :: DisplayForm -> Args -> MaybeT TCM DisplayTerm

Match a DisplayForm q ps = v against q vs. Return the DisplayTerm v[us] if the match was successful, i.e., vs / ps = Just us.

class Match a where

Class Match for matching a term p in the role of a pattern against a term v.

The 0th variable in p plays the role of a place holder (pattern variable). Each occurrence of var 0 in p stands for a different pattern variable.

The result of matching, if successful, is a list of solutions for the pattern variables, in left-to-right order.

The 0th variable is in scope in the input v, but should not actually occur! In the output solution, the 0th variable is no longer in scope. (It has been substituted by __IMPOSSIBLE__ which corresponds to a raise by -1).

Methods

match :: a -> a -> MaybeT TCM [Term]

Instances

Match Level

Match Sort

Match Term

Match a => Match [a]

Match a => Match (Elim' a)

Match a => Match (Arg a)