DDC.Source.Tetra.Transform.Defix

Convert infix expressions to prefix form.

The parser packs up sequences of expressions and operators into an XDefix node, but does not convert them to standard prefix applications. That is the job of this module.

The parsed code will contain XDefix, XInfixOp and XInfixVar nodes, which are pretty-printed like this:

 [DEFIX| Cons start [DEFIX| enumFromTo [DEFIX| start (INFIXOP "+") 1 ] end ]

After applying the transform in this module, all function applications will be in prefix form:

 Cons start (enumFromTo ((+) start 1) end)

Documentation

data FixTable l

Table of infix operator definitions.

Constructors

FixTable [FixDef l]

data FixDef l

Infix operator definition.

Constructors

FixDefPrefix

Fields

fixDefSymbol :: String

fixDefExp :: GAnnot l -> GExp l

FixDefInfix

Fields

fixDefSymbol :: String

fixDefExp :: GAnnot l -> GExp l

fixDefAssoc :: InfixAssoc

fixDefPrec :: Int

data InfixAssoc

Infix associativity.

Constructors

InfixLeft

Left associative.

InfixRight

Right associative.

InfixNone

Non associative.

Instances

Eq InfixAssoc

Show InfixAssoc

defaultFixTable :: (GBound l ~ Bound Name) => FixTable l

Default fixity table for infix operators.

data Error l

Things that can go wrong when defixing code.

Constructors

ErrorNoInfixDef

Infix operator symbol has no infix definition.

Fields

errorAnnot :: GAnnot l

errorSymbol :: String

ErrorDefixNonAssoc

Two non-associative operators with the same precedence.

Fields

errorOp1 :: String

errorAnnot1 :: GAnnot l

errorOp2 :: String

errorAnnot2 :: GAnnot l

ErrorDefixMixedAssoc

Two operators of different associativies with same precedence.

Fields

errorAnnot :: GAnnot l

errorOps :: [String]

ErrorMalformed

Infix expression is malformed. Eg "+ 3" or "2 + + 2"

Fields

errorAnnot :: GAnnot l

errorExp :: GExp l

Instances

ShowLanguage l => Show (Error l)

PrettyLanguage l => Pretty (Error l)

class Defix c l where

Methods

defix :: FixTable l -> c l -> Either (Error l) (c l)

Resolve infix expressions in a thing.

Instances

Defix GGuard l

Defix GGuardedExp l

Defix GAlt l

Defix GClause l

Defix GLets l

Defix GExp l

Defix Top l

Defix Module l