GHC Source Code Abbreviations

Certain abbreviations are used pervasively throughout the GHC source code. This page gives a partial list of them and their expansion:

• ANF: A-normal form

• BCO: Byte-code object

• CAF: Constant Applicative Form

• Class: Type Class

• Cmm: The final IR used in GHC, based on the C-- language

• Core: GHC core language. Based on System FC (variant of System F). Represents a type-checked and desugared program in some (out of several) intermediate compilation step

• CoreFV: Free variables in core

• CoreLint: Type and sanity-checking of core. (Lint: Jargon for a program analysis that looks for bug-suspicious code.)

• CoreSubst: Substitution in core

• CoreSyn: Core abstract syntax

• DataCon: Data constructor

• Ds: Desugarer

• Gbl: Global

• Hs: Haskell Syntax (generally as opposed to Core, for example, Expr vs HsExpr)

• Hsc: Haskell compiler. Means it Deals with compiling a single module and no more.

• HsSyn: Haskell abstract syntax

• Id: Synonym for Var, but indicating a term variable

• Iface: Interface, as in Haskell interface (.hi) files

• IfaceSyn: Interface abstract syntax

• LHs: Located Haskell something

• Loc: Location, as in SrcLoc

• Located: Something annotated with a SrcSpan

• Lcl: Local

• nativeGen: Native code generator (generates assembly from Cmm)

• Occ: Occurrence

  • However, in the context of OccName, "occurrence" actually means "classified (i.e. as a type name, value name, etc) but not qualified and not yet resolved"

• PId: Package ID

• PprCore: Pretty-printing core

• Rdr: Parser (or reader)

• Rn: Rename or Renamer

• Rts: Run Time System

• SimplCore: Simplify core (the so-called simplifier belongs to this, as does the strictness analyser)

• SrcLoc: Source location (filename, line number, character position)

• SrcSpan: Source location span (filename, start line number and character position, end line number and character position)

• STG: Spineless Tagless G-machine

• Tc: TypeCheck{ing,er}

• TSO: Thread State Object

• TyCon: Type constructor

• TyThing: Something that is type-checkable

• Ty: Type

• TyVar: Synonym for Var, but indicating a type variable

• Var: A variable with some information about its type (or kind)