parsegraph.dot

digraph G {
  rankdir=TB
  margin=0
  nodesep=0.1
  ranksep=0.4
  node [shape=box, style=rounded, fontname=Helvetica, fontsize=12, height=0.4]
  edge [arrowsize=0.8]

  Program -> {Function, DataDeclaration, TypeSignature, TypeclassDeclaration, InstanceDeclaration}

  Function -> {Name, Expr}
  DataDeclaration -> {DataType, Name, Tag}
  TypeSignature -> {Name, TypeHint}
  TypeclassDeclaration -> {Name, TypeHint}
  InstanceDeclaration -> {Name, TypeHint, Expr}

  Expr -> {ExprVariable, ExprLiteral, ExprConstructor, ExprApplication, ExprLet, ExprLambda, ExprCase}
  ExprVariable -> Name
  ExprConstructor -> {Tag, Arity}
  ExprApplication -> Expr
  ExprLet -> Expr
  ExprLambda -> Expr

  ExprCase -> {CaseAlternative, Expr}
  CaseAlternative -> {Pattern, Expr}

  Pattern -> {PatternVar, PatternWildcard, PatternLiteral, PatternConstructor}
  PatternVar -> Name
  PatternLiteral -> Literal
  PatternConstructor -> Tag
  PatternConstructor -> Pattern

  ExprLiteral -> Literal
  Literal -> {LiteralInt, LiteralString, LiteralDouble}

  TypeHint -> {TypeHintVar, TypeHintConstructor, TypeHintArrow, TypeHintConstraint}
  TypeHintVar -> Name
  TypeHintConstructor -> DataType
}