|Maintainer||Niklas Broberg, firstname.lastname@example.org|
Fixity information to give the parser so that infix operators can be parsed properly.
- data Fixity = Fixity Assoc Int Op
- infix_ :: Int -> [String] -> [Fixity]
- infixl_ :: Int -> [String] -> [Fixity]
- infixr_ :: Int -> [String] -> [Fixity]
- preludeFixities :: [Fixity]
- baseFixities :: [Fixity]
- class AppFixity ast where
Operator fixities are represented by their associativity (left, right or none) and their precedence (0-9).
The following three functions all create lists of fixities from textual representations of operators. The intended usage is e.g.
fixs = infixr_ 0 ["$","$!","`seq`"]
Note that the operators are expected as you would write them infix, i.e. with ` characters surrounding varid operators, and varsym operators written as is.
Collections of fixities
All fixities defined in the base package.
Note that the
+++ operator appears in both Control.Arrows and
Text.ParserCombinators.ReadP. The listed precedence for
this list is that of Control.Arrows.
Applying fixities to an AST
All AST elements that may include expressions which in turn may need fixity tweaking will be instances of this class.
|:: Monad m|
The fixities to account for.
|-> ast SrcSpanInfo|
The element to tweak.
|-> m (ast SrcSpanInfo)|
The same element, but with operator expressions updated, or a failure.
Tweak any expressions in the element to account for the fixities given. Assumes that all operator expressions are fully left associative chains to begin with.