Thanks a lot my good man. Is this Monte? https://github.com/monte-language/monte I can’t find the source code?

Can you tell me what you think of the code my implementation emits when you got the time? Is it good, bad, medicore etc?

So when you’re building a language, should you always use a builder for the AST specifications? Becuase I figure, you don’t need that in a language like Haskell or OCaml right?

I currently have 3 projects I ping-pong.

1- Marsh, a POSIX shell in C; 2- Awk2X; a translator of AWK to several languages, like C, Python Rust etc. This one is in Haskell 3- Cephyr; a C compiler in OCaml

For Marsh, I am stuck in the job control section. I just can’t seem to find a flow for redirecting input and output. I think I am striking a balance though. I revised the job control like 10 times, literally 10 times.

But for Awk2X and Cephyr, I am kinda stuck at defining the AST. I learned Haskell just last night and I made this AST. I am not ‘stuck’ really, I will move on from it soon.

data UnaryOp
  = Prefix PrefixOp
  | Postfix PostfixOp
  deriving (Show)

data PrefixOp
  = PrefixIncr
  | PrefixDecr
  | Plus
  | Minus
  | Not
  deriving (Show)

data PostfixOp
  = PostfixIncr
  | PostfixDecr
  deriving (Show)

data BinaryOp
  = Add
  | Sub
  | Mul
  | Div
  | Mod
  | Eq
  | Ne
  | Gt
  | Ge
  | Le
  | Lt
  | And
  | Or
  deriving (Show)

data Lvalue
  = Unfixed String
  | Fixed String String
  deriving (Show)

data Factor
  = Constant Constant
  | Lvalue Lvalue
  deriving (Show)

data Constant
  = String String
  | Integer Int
  | Float Float
  | Regex String
  deriving (Show)

data Expr
  = Unary UnaryOp Factor
  | Binary Factor BinaryOp Factor
  | Ternary Expr Expr Expr
  | StrCat [Expr]
  | Delete Expr
  | Call String [Expr]
  | Assign Lvalue Expr
  deriving (Show)

data Stmt
  = Express Expr
  | For Expr Expr Expr Stmt
  | ForIn Lvalue Lvalue Stmt
  | DoWhile Stmt Expr
  | While Expr Stmt
  | If Expr Stmt [(Expr, Stmt)] (Maybe (Expr, Stmt))
  | Return (Maybe Expr)
  | Break
  | Continue
  | Compound [Stmt]
  deriving (Show)

data Pattern
  = Begin
  | End
  | Expr Expr
  | ExprPair Expr Expr

data PatternAction
  = WithPattern Pattern [Stmt]
  | JustAction [Stmt]

data FunctionDefn = FunctionDefn
  { name :: String,
    params :: [String],
    body :: [Stmt]
  }

data Element
  = PattAct PatternAction
  | FnDef FunctionDefn

newtype Program = Program [Element

Now for Cephyr, this one is a bit more complex. Before Cephyr I attempted to make a C compiler several times, and every time I got stuck at the AST.

The problem is, I wanna use OCaml’s modules in the AST. But I don’t know how? I just said fuck it and used top-level types. I am here currently:

type const_expr
type type_decl
type unary_op
type binary_op
type expr
type stmt

type literal =
    ConstLiteral of const_lit | CompoundLiteral of compound_lit

and const_lit =
  | IntConst of int * int_suffix option
  | FloatCOnst of float * float_suffix option
  | CharConst of char * charset_prefix option
  | StrConst of string * charset_prefix option
  | IdentConst of string * const_expr

and int_suffix =
    Long | LongLong | Unsigned | UnsignedLong | UnsignedLongLOng

and float_suffix =
    Double | LongDouble

and charset_prefix =
    Local | U8 | U16 | U32

and compound_lit =
  | ArrayCompound of init_type * init_item list
  | StructCompound of init_type * init_item list
  | UnionCompound of init_type * init_item list

and init_item =
  | RegularInit of expr
  | DesignatedInit of designated_init * expr

and designated_init =
  | ConstExpr of const_expr
  | ConstExprPair of const_expr * const_expr
  | Ident of string

and init_type = type_decl


type const_expr =
  | UnaryConstExpr of { factor: literal; op: unary_op; }
  | BinaryConstExpr of { left_factor: literal; right_factor: literal; op: binary_op; }


type primary_factor =
    Identifier of string | NestedExpr of expr | Literal of literal

and expr =
  | Primary of primary_factor
  | Unary of { factor: primary_factor; op: unary_op; }
  | Subscript of { factor: primary_factor; op: subscript_op; }
  | Binary of { left_factor: expr; right_factor: expr; op: binary_op; }
  | Ternary of { cond: expr; if_true: expr; if_false: expr; }
  | Assignment of { lvalue: expr; rvalue: expr; op: assign_op; }

and prefix_unary_op =
  | Negate            
  | LogicalNegate     
  | BitwiseNot        
  | AddressOf         
  | Dereference       
  | PreIncrement      
  | PreDecrement      

and postfix_unary_op =
  | PostIncrement     
  | PostDecrement

and unary_op =
  | PrefixOp of prefix_unary_op
  | PostfixOp of postfix_unary_op

and subscript_op =
  | Index of expr
  | DotMember of expr
  | ArrowMember of expr
  | FunctionCall of expr list

and binary_op =
  | Add               
  | Subtract          
  | Multiply          
  | Divide            
  | Modulo            
  | BitwiseAnd        
  | BitwiseOr         
  | BitwiseXor        
  | ShiftLeft         
  | ShiftRight        
  | LogicalAnd        
  | LogicalOr         
  | Equal             
  | NotEqual          
  | LessThan          
  | LessThanOrEqual   
  | GreaterThan       
  | GreaterThanOrEqual 

and assign_op =
  | Assignment        
  | AddAssign         
  | SubtractAssign    
  | MultiplyAssign    
  | DivideAssign      
  | ModuloAssign      
  | AndAssign         
  | OrAssign          
  | XorAssign         
  | ShiftLeftAssign   
  | ShiftRightAssign

It’s still incomplete. I just found out I can use .mli files.

I think Cephyr is the 5th reincaation of my OCaml C compiler. I just spend hours at the AST and get tired of it.

I found lcc, by Fraiser et al:

https://github.com/drh/lcc

And I have the book too. I like the book but it’s kinda useless for me because I wanna do SSA. These kinda tree-rewriting mumbo jumbo is too 80s for my taste.

So any help is appreciated. Thanks.