Source file test.ml
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open Base
open Liquid_syntax
open Tools
open Syntax
open Parser_tools
let lex_to_equation a op b =
Equation (lex_value_to_value a, op, lex_value_to_value b)
let combine_condition p1 p2 c =
let combiner = match c with LexAnd -> And | LexOr -> Or in
match (p1, p2) with
| Always true, b2 -> b2
| b1, Always true -> b1
| _ -> Combine (combiner, p1, p2)
let build_condition tokens =
let is_unless = List.hd_exn tokens = Unless in
match tokens with
| Else :: _ -> Always true
| If :: statement | ElseIf :: statement | Unless :: statement ->
let rec aux acc pool =
match pool with
| [ LexValue a1 ] -> IsTruthy (lex_value_to_value a1)
| [ LexValue a1; Operator op1; LexValue b1 ] ->
lex_to_equation a1 op1 b1
| LexValue a1
:: Operator op1
:: LexValue b1
:: LexCombiner c
:: LexValue a2
:: Operator op2
:: LexValue b2
:: tl ->
let part_1 = lex_to_equation a1 op1 b1 in
let part_2 = lex_to_equation a2 op2 b2 in
let compound = combine_condition part_1 part_2 c in
aux compound tl
| LexCombiner c :: LexValue a1 :: Operator op1 :: LexValue b1 :: tl ->
let part_1 = lex_to_equation a1 op1 b1 in
let compound = combine_condition acc part_1 c in
aux compound tl
| [] -> acc
| _ -> Failure "Invalid condition" |> raise
in
let res = aux (Always true) statement in
if is_unless then Not res else res
| _ -> raise (Failure "Invalid token list")
let parse_test_statement block_parser chunk =
let cond_tokens, body_tokens = chunk |> scan_until_eos in
let condition = build_condition cond_tokens in
(condition, block_parser body_tokens)
let parse_when_statement block_parser case_id = function
| When :: tl ->
let vals, rest = scan_until_eos tl in
let make_eq v = Equation (Var case_id, Eq, lex_value_to_value v) in
let rec aux acc = function
| LexValue v :: Comma :: tl -> aux (acc @ [ make_eq v ]) tl
| LexValue v :: _ -> acc @ [ make_eq v ]
| _ -> acc
in
let conds = aux [] vals in
let rec unfold_into_or acc = function
| a :: b :: tl ->
unfold_into_or (Combine (Or, Combine (Or, a, b), acc)) tl
| a :: tl -> unfold_into_or (Combine (Or, a, acc)) tl
| _ -> acc
in
let condition = unfold_into_or (Always false) conds in
(condition, block_parser rest)
| Else :: tl -> (Always true, block_parser tl)
| _ -> raise (Failure "This is not a when statement")
let parse_when_statements block_parser case_id chunks =
let when_statements =
List.map chunks ~f:(parse_when_statement block_parser case_id)
in
let rec unfold_into_test = function
| (cond, body) :: tl -> Some (Test (cond, body, unfold_into_test tl))
| [] -> None
in
unfold_into_test when_statements
let parse_test_chain block_parser chunks =
let rec aux pool =
match pool with
| fs :: tl -> (
match fs with
| Case :: LexValue (LexId case_id) :: EOS :: _ ->
parse_when_statements block_parser case_id tl
| _ ->
let condition, body = parse_test_statement block_parser fs in
Some (Test (condition, body, aux tl)))
| [] -> None
in
match aux chunks with
| Some c -> c
| None -> raise (Failure "Failed to build if chain")