(* This module is a recursive descent parser for the ocamldoc syntax. The parser consumes a token stream of type [Token.t Stream.t], provided by the lexer, and produces a comment AST of the type defined in [Parser_.Ast]. The AST has two main levels: inline elements, which can appear inside paragraphs, and are spaced horizontally when presented, and block elements, such as paragraphs and lists, which are spaced vertically when presented. Block elements contain inline elements, but not vice versa. Corresponding to this, the parser has three "main" functions: - [delimited_inline_element_list] parses a run of inline elements that is delimited by curly brace markup ([{...}]). - [paragraph] parses a run of inline elements that make up a paragraph, and is not explicitly delimited with curly braces. - [block_element_list] parses a sequence of block elements. A comment is a sequence of block elements, so [block_element_list] is the top-level parser. It is also used for list item and tag content. *) open! Compat type 'a with_location = 'a Loc.with_location (* {2 Input} *) type input = { tokens : Token.t Loc.with_location Stream.t; warnings : Warning.t list ref; } (* {2 Output} *) let add_warning input warning = input.warnings := warning :: !(input.warnings) let junk input = Stream.junk input.tokens let peek input = match Stream.peek input.tokens with | Some token -> token | None -> assert false module Table = struct module Light_syntax = struct let valid_align = function | [ { Loc.value = `Word w; _ } ] -> ( match String.length w with | 0 -> `Valid None | 1 -> ( match w with | "-" -> `Valid None | ":" -> `Valid (Some `Center) | _ -> `Invalid) | len -> if String.for_all (Char.equal '-') (String.sub w 1 (len - 2)) then match (String.get w 0, String.get w (len - 1)) with | ':', ':' -> `Valid (Some `Center) | ':', '-' -> `Valid (Some `Left) | '-', ':' -> `Valid (Some `Right) | '-', '-' -> `Valid None | _ -> `Invalid else `Invalid) | _ -> `Invalid let valid_align_row lx = let rec loop acc = function | [] -> Some (List.rev acc) | x :: q -> ( match valid_align x with | `Invalid -> None | `Valid alignment -> loop (alignment :: acc) q) in loop [] lx let create ~grid ~align : Ast.table = let cell_to_block (x, k) = let whole_loc = Loc.span (List.map (fun x -> x.Loc.location) x) in match x with | [] -> ([], k) | _ -> ([ Loc.at whole_loc (`Paragraph x) ], k) in let row_to_block = List.map cell_to_block in let grid_to_block = List.map row_to_block in ((grid_to_block grid, align), `Light) let with_kind kind : 'a with_location list list -> 'a Ast.row = List.map (fun c -> (c, kind)) let from_raw_data grid : Ast.table = match grid with | [] -> create ~grid:[] ~align:None | row1 :: rows2_N -> ( match valid_align_row row1 with (* If the first line is the align row, everything else is data. *) | Some _ as align -> create ~grid:(List.map (with_kind `Data) rows2_N) ~align | None -> ( match rows2_N with (* Only 1 line, if this is not the align row this is data. *) | [] -> create ~grid:[ with_kind `Data row1 ] ~align:None | row2 :: rows3_N -> ( match valid_align_row row2 with (* If the second line is the align row, the first one is the header and the rest is data. *) | Some _ as align -> let header = with_kind `Header row1 in let data = List.map (with_kind `Data) rows3_N in create ~grid:(header :: data) ~align (* No align row in the first 2 lines, everything is considered data. *) | None -> create ~grid:(List.map (with_kind `Data) grid) ~align:None ))) end module Heavy_syntax = struct let create ~grid : Ast.table = ((grid, None), `Heavy) let from_grid grid : Ast.table = create ~grid end end module Reader = struct let until_rbrace_or_eof input acc = let rec consume () = let next_token = peek input in match next_token.value with | `Right_brace -> junk input; `End (acc, next_token.location) | `End -> Parse_error.end_not_allowed next_token.location ~in_what:"table" |> add_warning input; junk input; `End (acc, next_token.location) | `Space _ | `Single_newline _ | `Blank_line _ -> junk input; consume () | _ -> `Token next_token in consume () module Infix = struct let ( >>> ) consume if_token = match consume with | `End (ret, loc) -> (ret, loc) | `Token t -> if_token t end end open Reader.Infix (* The last token in the stream is always [`End], and it is never consumed by the parser, so the [None] case is impossible. *) let npeek n input = Stream.npeek n input.tokens (* {2 Non-link inline elements} *) type style = [ `Bold | `Italic | `Emphasis | `Superscript | `Subscript ] (* Convenient abbreviation for use in patterns. *) type token_that_always_begins_an_inline_element = [ `Word of string | `Code_span of string | `Raw_markup of string option * string | `Begin_style of style | `Simple_reference of string | `Begin_reference_with_replacement_text of string | `Simple_link of string | `Begin_link_with_replacement_text of string | `Math_span of string ] (* Check that the token constructors above actually are all in [Token.t]. *) let _check_subset : token_that_always_begins_an_inline_element -> Token.t = fun t -> (t :> Token.t) (* Consumes tokens that make up a single non-link inline element: - a horizontal space ([`Space], significant in inline elements), - a word (see [word]), - a code span ([...], [`Code_span _]), or - styled text ({e ...}). The latter requires a recursive call to [delimited_inline_element_list], defined below. This should be part of [delimited_inline_element_list]; however, it is also called by function [paragraph]. As a result, it is factored out, and made mutually-recursive with [delimited_inline_element_list]. This is called only when it is known that the first token in the list is the beginning of an inline element. In the case of [`Minus] and [`Plus], that means the caller has determined that they are not a list bullet (i.e., not the first non-whitespace tokens on their line). This function consumes exactly the tokens that make up the element. *) let rec inline_element : input -> Loc.span -> _ -> Ast.inline_element with_location = fun input location next_token -> match next_token with | `Space _ as token -> junk input; Loc.at location token | `Word _ as token -> junk input; Loc.at location token (* This is actually the same memory representation as the token, complete with location, and is probably the most common case. Perhaps the token can be reused somehow. The same is true of [`Space], [`Code_span]. *) | `Minus -> junk input; Loc.at location (`Word "-") | `Plus -> junk input; Loc.at location (`Word "+") | `Bar -> junk input; Loc.at location (`Word "|") | (`Code_span _ | `Math_span _ | `Raw_markup _) as token -> junk input; Loc.at location token | `Begin_style s as parent_markup -> junk input; let requires_leading_whitespace = match s with | `Bold | `Italic | `Emphasis -> true | `Superscript | `Subscript -> false in let content, brace_location = delimited_inline_element_list ~parent_markup ~parent_markup_location:location ~requires_leading_whitespace input in let location = Loc.span [ location; brace_location ] in if content = [] then Parse_error.should_not_be_empty ~what:(Token.describe parent_markup) location |> add_warning input; Loc.at location (`Styled (s, content)) | `Simple_reference r -> junk input; let r_location = Loc.nudge_start (String.length "{!") location in let r = Loc.at r_location r in Loc.at location (`Reference (`Simple, r, [])) | `Begin_reference_with_replacement_text r as parent_markup -> junk input; let r_location = Loc.nudge_start (String.length "{{!") location in let r = Loc.at r_location r in let content, brace_location = delimited_inline_element_list ~parent_markup ~parent_markup_location:location ~requires_leading_whitespace:false input in let location = Loc.span [ location; brace_location ] in if content = [] then Parse_error.should_not_be_empty ~what:(Token.describe parent_markup) location |> add_warning input; Loc.at location (`Reference (`With_text, r, content)) | `Simple_link u -> junk input; let u = String.trim u in if u = "" then Parse_error.should_not_be_empty ~what:(Token.describe next_token) location |> add_warning input; Loc.at location (`Link (u, [])) | `Begin_link_with_replacement_text u as parent_markup -> junk input; let u = String.trim u in if u = "" then Parse_error.should_not_be_empty ~what:(Token.describe parent_markup) location |> add_warning input; let content, brace_location = delimited_inline_element_list ~parent_markup ~parent_markup_location:location ~requires_leading_whitespace:false input in `Link (u, content) |> Loc.at (Loc.span [ location; brace_location ]) (* Consumes tokens that make up a sequence of inline elements that is ended by a '}', a [`Right_brace] token. The brace token is also consumed. The sequences are also preceded by some markup like '{b'. Some of these markup tokens require whitespace immediately after the token, and others not. The caller indicates which way that is through the [~requires_leading_whitespace] argument. Whitespace is significant in inline element lists. In particular, "foo [bar]" is represented as [`Word "foo"; `Space; `Code_span "bar"], while "foo[bar]" is [`Word "foo"; `Code_span "bar"]. It doesn't matter how much whitespace is there, just whether it is present or not. Single newlines and horizontal space in any amount are allowed. Blank lines are not, as these are separators for {e block} elements. In correct input, the first and last elements emitted will not be [`Space], i.e. [`Space] appears only between other non-link inline elements. In incorrect input, there might be [`Space] followed immediately by something like an @author tag. The [~parent_markup] and [~parent_markup_location] arguments are used for generating error messages. *) and delimited_inline_element_list : parent_markup:[< Token.t ] -> parent_markup_location:Loc.span -> requires_leading_whitespace:bool -> input -> Ast.inline_element with_location list * Loc.span = fun ~parent_markup ~parent_markup_location ~requires_leading_whitespace input -> (* [~at_start_of_line] is used to interpret [`Minus] and [`Plus]. These are word tokens if not the first non-whitespace tokens on their line. Then, they are allowed in a non-link element list. *) let rec consume_elements : at_start_of_line:bool -> Ast.inline_element with_location list -> Ast.inline_element with_location list * Loc.span = fun ~at_start_of_line acc -> let next_token = peek input in match next_token.value with | `Right_brace -> junk input; (List.rev acc, next_token.location) (* The [`Space] token is not space at the beginning or end of line, because that is combined into [`Single_newline] or [`Blank_line] tokens. It is also not at the beginning of markup (after e.g. '{b'), because that is handled separately before calling [consume_non_link_inline_elements], and not immediately before '}', because that is combined into the [`Right_brace] token by the lexer. So, it is an internal space, and we want to add it to the non-link inline element list. *) | (`Space _ | #token_that_always_begins_an_inline_element) as token -> let acc = inline_element input next_token.location token :: acc in consume_elements ~at_start_of_line:false acc | `Single_newline ws -> junk input; let element = Loc.same next_token (`Space ws) in consume_elements ~at_start_of_line:true (element :: acc) | `Blank_line ws as blank -> Parse_error.not_allowed ~what:(Token.describe blank) ~in_what:(Token.describe parent_markup) next_token.location |> add_warning input; junk input; let element = Loc.same next_token (`Space ws) in consume_elements ~at_start_of_line:true (element :: acc) | `Bar as token -> let acc = inline_element input next_token.location token :: acc in consume_elements ~at_start_of_line:false acc | (`Minus | `Plus) as bullet -> (if at_start_of_line then let suggestion = Printf.sprintf "move %s so it isn't the first thing on the line." (Token.print bullet) in Parse_error.not_allowed ~what:(Token.describe bullet) ~in_what:(Token.describe parent_markup) ~suggestion next_token.location |> add_warning input); let acc = inline_element input next_token.location bullet :: acc in consume_elements ~at_start_of_line:false acc | other_token -> Parse_error.not_allowed ~what:(Token.describe other_token) ~in_what:(Token.describe parent_markup) next_token.location |> add_warning input; let last_location = match acc with | last_token :: _ -> last_token.location | [] -> parent_markup_location in (List.rev acc, last_location) in let first_token = peek input in match first_token.value with | `Space _ -> junk input; consume_elements ~at_start_of_line:false [] (* [~at_start_of_line] is [false] here because the preceding token was some some markup like '{b', and we didn't move to the next line, so the next token will not be the first non-whitespace token on its line. *) | `Single_newline _ -> junk input; consume_elements ~at_start_of_line:true [] | `Blank_line _ as blank -> (* In case the markup is immediately followed by a blank line, the error message printed by the catch-all case below can be confusing, as it will suggest that the markup must be followed by a newline (which it is). It just must not be followed by two newlines. To explain that clearly, handle that case specifically. *) Parse_error.not_allowed ~what:(Token.describe blank) ~in_what:(Token.describe parent_markup) first_token.location |> add_warning input; junk input; consume_elements ~at_start_of_line:true [] | `Right_brace -> junk input; ([], first_token.location) | _ -> if requires_leading_whitespace then Parse_error.should_be_followed_by_whitespace ~what:(Token.print parent_markup) parent_markup_location |> add_warning input; consume_elements ~at_start_of_line:false [] (* {2 Paragraphs} *) (* Consumes tokens that make up a paragraph. A paragraph is a sequence of inline elements that ends on a blank line, or explicit block markup such as a verbatim block on a new line. Because of the significance of newlines, paragraphs are parsed line-by-line. The function [paragraph] is called only when the current token is the first non-whitespace token on its line, and begins an inline element. [paragraph] then parses a line of inline elements. Afterwards, it looks ahead to the next line. If that line also begins with an inline element, it parses that line, and so on. *) let paragraph : input -> Ast.nestable_block_element with_location = fun input -> (* Parses a single line of a paragraph, consisting of inline elements. The only valid ways to end a paragraph line are with [`End], [`Single_newline], [`Blank_line], and [`Right_brace]. Everything else either belongs in the paragraph, or signifies an attempt to begin a block element inside a paragraph line, which is an error. These errors are caught elsewhere; the paragraph parser just stops. *) let rec paragraph_line : Ast.inline_element with_location list -> Ast.inline_element with_location list = fun acc -> let next_token = peek input in match next_token.value with | ( `Space _ | `Minus | `Plus | `Bar | #token_that_always_begins_an_inline_element ) as token -> let element = inline_element input next_token.location token in paragraph_line (element :: acc) | _ -> acc in (* After each line is parsed, decides whether to parse more lines. *) let rec additional_lines : Ast.inline_element with_location list -> Ast.inline_element with_location list = fun acc -> match npeek 2 input with | { value = `Single_newline ws; location } :: { value = #token_that_always_begins_an_inline_element | `Bar; _ } :: _ -> junk input; let acc = Loc.at location (`Space ws) :: acc in let acc = paragraph_line acc in additional_lines acc | _ -> List.rev acc in let elements = paragraph_line [] |> additional_lines in `Paragraph elements |> Loc.at (Loc.span (List.map Loc.location elements)) (* {2 Block elements} *) (* {3 Helper types} *) (* The interpretation of tokens in the block parser depends on where on a line each token appears. The six possible "locations" are: - [`At_start_of_line], when only whitespace has been read on the current line. - [`After_tag], when a valid tag token, such as [@deprecated], has been read, and only whitespace has been read since. - [`After_shorthand_bullet], when a valid shorthand list item bullet, such as [-], has been read, and only whitespace has been read since. - [`After_explicit_list_bullet], when a valid explicit bullet, such as [{li], has been read, and only whitespace has been read since. - [`After_table_cell], when a table cell opening markup ('{th' or '{td') has been read. - [`After_text], when any other valid non-whitespace token has already been read on the current line. Here are some examples of how this affects the interpretation of tokens: - A paragraph can start anywhere except [`After_text] (two paragraphs cannot be on the same line, but paragraphs can be nested in just about anything). - [`Minus] is interpreted as a list item bullet [`At_start_of_line], [`After_tag], and [`After_explicit_list_bullet]. - Tags are only allowed [`At_start_of_line]. To track the location accurately, the functions that make up the block parser pass explicit [where_in_line] values around and return them. In a few cases, [where_in_line] can be inferred from what helper was called. For example, the [paragraph] parser always stops on the same line as the last significant token that is in the paragraph it consumed, so the location must be [`After_text]. *) type where_in_line = [ `At_start_of_line | `After_tag | `After_shorthand_bullet | `After_explicit_list_bullet | `After_table_cell | `After_text ] (* The block parsing loop, function [block_element_list], stops when it encounters certain tokens. When it is called for the whole comment, or for in explicit list item ([{li foo}]), it can only stop on end of input or a right brace. When it is called inside a shorthand list item ([- foo]), it stops on end of input, right brace, a blank line (indicating end of shorthand list), plus or minus (indicating the start of the next list item), or a section heading or tag, which cannot be nested in list markup. The block parser [block_element_list] explicitly returns the token that stopped it, with a type more precise than [Token.t stream_head]: if it was called for the whole comment or an explicit list item, the stop token will have type [stops_at_delimiters stream_head], and if it was called for a shorthand list item, the stop token will have type [implicit_stop stream_head]. This allows the calling parsers to write precise cases for exactly the tokens that might be at the front of the stream after the block parser returns. *) type stops_at_delimiters = [ `End | `Right_brace ] type code_stop = [ `End | `Right_code_delimiter ] type stopped_implicitly = [ `End | `Blank_line of string | `Right_brace | `Minus | `Plus | Token.section_heading | Token.media_markup | Token.tag ] (* Ensure that the above two types are really subsets of [Token.t]. *) let _check_subset : stops_at_delimiters -> Token.t = fun t -> (t :> Token.t) let _check_subset : stopped_implicitly -> Token.t = fun t -> (t :> Token.t) (* The different contexts in which the block parser [block_element_list] can be called. The block parser's behavior depends somewhat on the context. For example, while paragraphs are allowed anywhere, shorthand lists are not allowed immediately inside other shorthand lists, while tags are not allowed anywhere except at the comment top level. Besides telling the block parser how to behave, each context also carries two types, which determine the return type of the block parser: - The type of blocks the parser returns. Note that [nestable_block_element] is included in [block_element]. However, the extra block kinds in [block_element] are only allowed at the comment top level. - The type of token that the block parser stops at. See discussion above. *) type ('block, 'stops_at_which_tokens) context = | Top_level : (Ast.block_element, stops_at_delimiters) context | In_implicitly_ended : [ `Tag | `Shorthand_list ] -> (Ast.nestable_block_element, stopped_implicitly) context | In_explicit_list : (Ast.nestable_block_element, stops_at_delimiters) context | In_table_cell : (Ast.nestable_block_element, stops_at_delimiters) context | In_code_results : (Ast.nestable_block_element, code_stop) context (* This is a no-op. It is needed to prove to the type system that nestable block elements are acceptable block elements in all contexts. *) let accepted_in_all_contexts : type block stops_at_which_tokens. (block, stops_at_which_tokens) context -> Ast.nestable_block_element -> block = fun context block -> match context with | Top_level -> (block :> Ast.block_element) | In_implicitly_ended (`Tag | `Shorthand_list) -> block | In_explicit_list -> block | In_table_cell -> block | In_code_results -> block (* Converts a tag to a series of words. This is used in error recovery, when a tag cannot be generated. *) let tag_to_words = function | `Author s -> [ `Word "@author"; `Space " "; `Word s ] | `Before s -> [ `Word "@before"; `Space " "; `Word s ] | `Canonical s -> [ `Word "@canonical"; `Space " "; `Word s ] | `Deprecated -> [ `Word "@deprecated" ] | `Inline -> [ `Word "@inline" ] | `Open -> [ `Word "@open" ] | `Closed -> [ `Word "@closed" ] | `Hidden -> [ `Word "@hidden" ] | `Param s -> [ `Word "@param"; `Space " "; `Word s ] | `Raise s -> [ `Word "@raise"; `Space " "; `Word s ] | `Return -> [ `Word "@return" ] | `See (`Document, s) -> [ `Word "@see"; `Space " "; `Word ("\"" ^ s ^ "\"") ] | `See (`File, s) -> [ `Word "@see"; `Space " "; `Word ("'" ^ s ^ "'") ] | `See (`Url, s) -> [ `Word "@see"; `Space " "; `Word ("<" ^ s ^ ">") ] | `Since s -> [ `Word "@since"; `Space " "; `Word s ] | `Version s -> [ `Word "@version"; `Space " "; `Word s ] | `Children_order -> [ `Word "@children_order" ] | `Toc_status -> [ `Word "@toc_status" ] | `Order_category -> [ `Word "@order_category" ] | `Short_title -> [ `Word "@short_title" ] | `Custom tag -> [ `Word ("@" ^ tag) ] (* {3 Block element lists} *) (* Consumes tokens making up a sequence of block elements. These are: - paragraphs, - code blocks, - verbatim text blocks, - tables, - lists, and - section headings. *) let rec block_element_list : type block stops_at_which_tokens. (block, stops_at_which_tokens) context -> parent_markup:[< Token.t | `Comment ] -> input -> block with_location list * stops_at_which_tokens with_location * where_in_line = fun context ~parent_markup input -> let rec consume_block_elements : where_in_line -> block with_location list -> block with_location list * stops_at_which_tokens with_location * where_in_line = fun where_in_line acc -> let describe token = match token with | #token_that_always_begins_an_inline_element -> "paragraph" | _ -> Token.describe token in let warn_if_after_text { Loc.location; value = token } = if where_in_line = `After_text then Parse_error.should_begin_on_its_own_line ~what:(describe token) location |> add_warning input in let warn_because_not_at_top_level { Loc.location; value = token } = let suggestion = Printf.sprintf "move %s outside of any other markup." (Token.print token) in Parse_error.not_allowed ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion location |> add_warning input in match peek input with (* Terminators: the two tokens that terminate anything. *) | { value = `End; _ } as next_token -> ( match context with | Top_level -> (List.rev acc, next_token, where_in_line) | In_implicitly_ended (`Tag | `Shorthand_list) -> (List.rev acc, next_token, where_in_line) | In_explicit_list -> (List.rev acc, next_token, where_in_line) | In_table_cell -> (List.rev acc, next_token, where_in_line) | In_code_results -> (List.rev acc, next_token, where_in_line)) | { value = `Right_brace; _ } as next_token -> ( (* This little absurdity is needed to satisfy the type system. Without it, OCaml is unable to prove that [stream_head] has the right type for all possible values of [context]. *) match context with | Top_level -> (List.rev acc, next_token, where_in_line) | In_implicitly_ended (`Tag | `Shorthand_list) -> (List.rev acc, next_token, where_in_line) | In_explicit_list -> (List.rev acc, next_token, where_in_line) | In_table_cell -> (List.rev acc, next_token, where_in_line) | In_code_results -> junk input; consume_block_elements where_in_line acc) | { value = `Right_code_delimiter; _ } as next_token -> ( match context with | In_code_results -> (List.rev acc, next_token, where_in_line) | _ -> junk input; consume_block_elements where_in_line acc) (* Whitespace. This can terminate some kinds of block elements. It is also necessary to track it to interpret [`Minus] and [`Plus] correctly, as well as to ensure that all block elements begin on their own line. *) | { value = `Space _; _ } -> junk input; consume_block_elements where_in_line acc | { value = `Single_newline _; _ } -> junk input; consume_block_elements `At_start_of_line acc | { value = `Blank_line _; _ } as next_token -> ( match context with (* Blank lines terminate shorthand lists ([- foo]) and tags. They also terminate paragraphs, but the paragraph parser is aware of that internally. *) | In_implicitly_ended (`Tag | `Shorthand_list) -> (List.rev acc, next_token, where_in_line) (* Otherwise, blank lines are pretty much like single newlines. *) | _ -> junk input; consume_block_elements `At_start_of_line acc) (* Explicit list items ([{li ...}] and [{- ...}]) can never appear directly in block content. They can only appear inside [{ul ...}] and [{ol ...}]. So, catch those. *) | { value = `Begin_list_item _ as token; location } -> let suggestion = Printf.sprintf "move %s into %s, or use %s." (Token.print token) (Token.describe (`Begin_list `Unordered)) (Token.describe `Minus) in Parse_error.not_allowed ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion location |> add_warning input; junk input; consume_block_elements where_in_line acc (* Table rows ([{tr ...}]) can never appear directly in block content. They can only appear inside [{table ...}]. *) | { value = `Begin_table_row as token; location } -> let suggestion = Printf.sprintf "move %s into %s." (Token.print token) (Token.describe `Begin_table_heavy) in Parse_error.not_allowed ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion location |> add_warning input; junk input; consume_block_elements where_in_line acc (* Table cells ([{th ...}] and [{td ...}]) can never appear directly in block content. They can only appear inside [{tr ...}]. *) | { value = `Begin_table_cell _ as token; location } -> let suggestion = Printf.sprintf "move %s into %s." (Token.print token) (Token.describe `Begin_table_row) in Parse_error.not_allowed ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion location |> add_warning input; junk input; consume_block_elements where_in_line acc (* Tags. These can appear at the top level only. *) | { value = `Tag tag as token; location } as next_token -> ( let recover_when_not_at_top_level context = warn_because_not_at_top_level next_token; junk input; let words = List.map (Loc.at location) (tag_to_words tag) in let paragraph = `Paragraph words |> accepted_in_all_contexts context |> Loc.at location in consume_block_elements `At_start_of_line (paragraph :: acc) in match context with (* Tags cannot make sense in an explicit list ([{ul {li ...}}]). *) | In_explicit_list -> recover_when_not_at_top_level context (* If a tag starts at the beginning of a line, it terminates the preceding tag and/or the current shorthand list. In this case, return to the caller, and let the caller decide how to interpret the tag token. *) | In_implicitly_ended (`Tag | `Shorthand_list) -> if where_in_line = `At_start_of_line then (List.rev acc, next_token, where_in_line) else recover_when_not_at_top_level context | In_table_cell -> recover_when_not_at_top_level context | In_code_results -> recover_when_not_at_top_level context (* If this is the top-level call to [block_element_list], parse the tag. *) | Top_level -> ( if where_in_line <> `At_start_of_line then Parse_error.should_begin_on_its_own_line ~what:(Token.describe token) location |> add_warning input; junk input; match tag with | (`Author s | `Since s | `Version s | `Canonical s) as tag -> let s = String.trim s in if s = "" then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; let tag = match tag with | `Author _ -> `Author s | `Since _ -> `Since s | `Version _ -> `Version s | `Canonical _ -> (* TODO The location is only approximate, as we need lexer cooperation to get the real location. *) let r_location = Loc.nudge_start (String.length "@canonical ") location in `Canonical (Loc.at r_location s) in let tag = Loc.at location (`Tag tag) in consume_block_elements `After_text (tag :: acc) | ( `Deprecated | `Return | `Children_order | `Short_title | `Toc_status | `Order_category | `Custom _ ) as tag -> let content, _stream_head, where_in_line = block_element_list (In_implicitly_ended `Tag) ~parent_markup:token input in let tag = match tag with | `Deprecated -> `Deprecated content | `Toc_status -> `Toc_status content | `Return -> `Return content | `Children_order -> `Children_order content | `Short_title -> `Short_title content | `Order_category -> `Order_category content | `Custom s -> `Custom (s, content) in let location = location :: List.map Loc.location content |> Loc.span in let tag = Loc.at location (`Tag tag) in consume_block_elements where_in_line (tag :: acc) | (`Param _ | `Raise _ | `Before _) as tag -> let content, _stream_head, where_in_line = block_element_list (In_implicitly_ended `Tag) ~parent_markup:token input in let tag = match tag with | `Param s -> `Param (s, content) | `Raise s -> `Raise (s, content) | `Before s -> `Before (s, content) in let location = location :: List.map Loc.location content |> Loc.span in let tag = Loc.at location (`Tag tag) in consume_block_elements where_in_line (tag :: acc) | `See (kind, target) -> let content, _next_token, where_in_line = block_element_list (In_implicitly_ended `Tag) ~parent_markup:token input in let location = location :: List.map Loc.location content |> Loc.span in let tag = `Tag (`See (kind, target, content)) in let tag = Loc.at location tag in consume_block_elements where_in_line (tag :: acc) | (`Inline | `Open | `Closed | `Hidden) as tag -> let tag = Loc.at location (`Tag tag) in consume_block_elements `After_text (tag :: acc))) | ( { value = #token_that_always_begins_an_inline_element; _ } | { value = `Bar; _ } ) as next_token -> warn_if_after_text next_token; let block = paragraph input in let block = Loc.map (accepted_in_all_contexts context) block in let acc = block :: acc in consume_block_elements `After_text acc | { value = `Verbatim s as token; location } as next_token -> warn_if_after_text next_token; if s = "" then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; junk input; let block = accepted_in_all_contexts context token in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { value = `Math_block s as token; location } as next_token -> warn_if_after_text next_token; if s = "" then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; junk input; let block = accepted_in_all_contexts context token in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { value = `Code_block (meta, delim, { value = s; location = v_loc }, has_outputs) as token; location; } as next_token -> warn_if_after_text next_token; junk input; let delimiter = if delim = "" then None else Some delim in let output, location = if not has_outputs then (None, location) else let content, next_token, _where_in_line = block_element_list In_code_results ~parent_markup:token input in junk input; let locations = location :: List.map (fun content -> content.Loc.location) content in let location = Loc.span locations in let location = { location with end_ = next_token.location.end_ } in (Some content, location) in if s = "" then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; let meta = match meta with | None -> None | Some (language, tags) -> Some { Ast.language; tags } in let block = accepted_in_all_contexts context (`Code_block { Ast.meta; delimiter; content = { value = s; location = v_loc }; output; }) in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { value = `Modules s as token; location } as next_token -> warn_if_after_text next_token; junk input; (* TODO Use some library for a splitting function, or move this out into a Util module. *) let split_string delimiters s = let rec scan_delimiters acc index = if index >= String.length s then List.rev acc else if String.contains delimiters s.[index] then scan_delimiters acc (index + 1) else scan_word acc index (index + 1) and scan_word acc start_index index = if index >= String.length s then let word = String.sub s start_index (index - start_index) in List.rev (word :: acc) else if String.contains delimiters s.[index] then let word = String.sub s start_index (index - start_index) in scan_delimiters (word :: acc) (index + 1) else scan_word acc start_index (index + 1) in scan_delimiters [] 0 in (* TODO Correct locations await a full implementation of {!modules} parsing. *) let modules = split_string " \t\r\n" s |> List.map (fun r -> Loc.at location r) in if modules = [] then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; let block = accepted_in_all_contexts context (`Modules modules) in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { value = `Begin_list kind as token; location } as next_token -> warn_if_after_text next_token; junk input; let items, brace_location = explicit_list_items ~parent_markup:token input in if items = [] then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; let location = Loc.span [ location; brace_location ] in let block = `List (kind, `Heavy, items) in let block = accepted_in_all_contexts context block in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { value = (`Begin_table_light | `Begin_table_heavy) as token; location } as next_token -> warn_if_after_text next_token; junk input; let block, brace_location = let parent_markup = token in let parent_markup_location = location in match token with | `Begin_table_light -> light_table input ~parent_markup ~parent_markup_location | `Begin_table_heavy -> heavy_table input ~parent_markup ~parent_markup_location in let location = Loc.span [ location; brace_location ] in let block = accepted_in_all_contexts context (`Table block) in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { value = (`Minus | `Plus) as token; location } as next_token -> ( (match where_in_line with | `After_text | `After_shorthand_bullet -> Parse_error.should_begin_on_its_own_line ~what:(Token.describe token) location |> add_warning input | _ -> ()); match context with | In_implicitly_ended `Shorthand_list -> (List.rev acc, next_token, where_in_line) | _ -> let items, where_in_line = shorthand_list_items next_token where_in_line input in let kind = match token with `Minus -> `Unordered | `Plus -> `Ordered in let location = location :: List.map Loc.location (List.flatten items) |> Loc.span in let block = `List (kind, `Light, items) in let block = accepted_in_all_contexts context block in let block = Loc.at location block in let acc = block :: acc in consume_block_elements where_in_line acc) | { value = `Begin_section_heading (level, label) as token; location } as next_token -> ( let recover_when_not_at_top_level context = warn_because_not_at_top_level next_token; junk input; let content, brace_location = delimited_inline_element_list ~parent_markup:token ~parent_markup_location:location ~requires_leading_whitespace:true input in let location = Loc.span [ location; brace_location ] in let paragraph = `Paragraph content |> accepted_in_all_contexts context |> Loc.at location in consume_block_elements `At_start_of_line (paragraph :: acc) in match context with | In_implicitly_ended (`Tag | `Shorthand_list) -> if where_in_line = `At_start_of_line then (List.rev acc, next_token, where_in_line) else recover_when_not_at_top_level context | In_explicit_list -> recover_when_not_at_top_level context | In_table_cell -> recover_when_not_at_top_level context | In_code_results -> recover_when_not_at_top_level context | Top_level -> if where_in_line <> `At_start_of_line then Parse_error.should_begin_on_its_own_line ~what:(Token.describe token) location |> add_warning input; let label = match label with | Some "" -> Parse_error.should_not_be_empty ~what:"heading label" location |> add_warning input; None | _ -> label in junk input; let content, brace_location = delimited_inline_element_list ~parent_markup:token ~parent_markup_location:location ~requires_leading_whitespace:true input in if content = [] then Parse_error.should_not_be_empty ~what:(Token.describe token) location |> add_warning input; let location = Loc.span [ location; brace_location ] in let heading = `Heading (level, label, content) in let heading = Loc.at location heading in let acc = heading :: acc in consume_block_elements `After_text acc) | { value = `Begin_paragraph_style _ as token; location } -> junk input; let content, brace_location = delimited_inline_element_list ~parent_markup:token ~parent_markup_location:location ~requires_leading_whitespace:true input in let location = Loc.span [ location; brace_location ] in Parse_error.markup_should_not_be_used ~what:(Token.describe token) location |> add_warning input; let paragraph = `Paragraph content |> accepted_in_all_contexts context |> Loc.at location in consume_block_elements `At_start_of_line (paragraph :: acc) | { location; value = `Media_with_replacement_text (href, media, content) as token; } -> junk input; let r_location = Loc.nudge_start (String.length @@ Token.s_of_media `Replaced media) location |> Loc.nudge_end (String.length content + 1) (* +1 for closing character *) in let c_location = Loc.nudge_start (String.length (Token.s_of_media `Replaced media) + String.length (match href with `Reference s | `Link s -> s)) location |> Loc.nudge_end 1 in let content = String.trim content in let href = href |> Loc.at r_location in if content = "" then Parse_error.should_not_be_empty ~what:(Token.describe token) c_location |> add_warning input; let block = `Media (`Simple, href, content, media) in let block = accepted_in_all_contexts context block in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc | { location; value = `Simple_media (href, media) } -> junk input; let r_location = Loc.nudge_start (String.length @@ Token.s_of_media `Simple media) location |> Loc.nudge_end 1 in let href = href |> Loc.at r_location in let block = `Media (`Simple, href, "", media) in let block = accepted_in_all_contexts context block in let block = Loc.at location block in let acc = block :: acc in consume_block_elements `After_text acc in let where_in_line = match context with | Top_level -> `At_start_of_line | In_implicitly_ended `Shorthand_list -> `After_shorthand_bullet | In_explicit_list -> `After_explicit_list_bullet | In_table_cell -> `After_table_cell | In_code_results -> `After_tag | In_implicitly_ended `Tag -> `After_tag in consume_block_elements where_in_line [] (* {3 Lists} *) (* Consumes a sequence of implicit list items. Each one consists of a [`Minus] or [`Plus] token, followed by block elements until: - a blank line, or - a list bullet of the opposite kind (e.g. [`Plus] for a [`Minus] list). This function is called when the next token is known to be [`Minus] or [`Plus]. It consumes that token, and calls the block element parser (see above). That parser returns to [implicit_list_items] only on [`Blank_line], [`End], [`Minus] or [`Plus] at the start of a line, or [`Right_brace]. *) and shorthand_list_items : [ `Minus | `Plus ] with_location -> where_in_line -> input -> Ast.nestable_block_element with_location list list * where_in_line = fun first_token where_in_line input -> let bullet_token = first_token.value in let rec consume_list_items : [> ] with_location -> where_in_line -> Ast.nestable_block_element with_location list list -> Ast.nestable_block_element with_location list list * where_in_line = fun next_token where_in_line acc -> match next_token.value with | `End | `Right_brace | `Blank_line _ | `Tag _ | `Begin_section_heading _ | `Simple_media _ | `Media_with_replacement_text _ -> (List.rev acc, where_in_line) | (`Minus | `Plus) as bullet -> if bullet = bullet_token then ( junk input; let content, stream_head, where_in_line = block_element_list (In_implicitly_ended `Shorthand_list) ~parent_markup:bullet input in if content = [] then Parse_error.should_not_be_empty ~what:(Token.describe bullet) next_token.location |> add_warning input; let acc = content :: acc in consume_list_items stream_head where_in_line acc) else (List.rev acc, where_in_line) in consume_list_items (first_token :> stopped_implicitly with_location) where_in_line [] (* Consumes a sequence of explicit list items (starting with '{li ...}' and '{-...}', which are represented by [`Begin_list_item _] tokens). This function is called immediately after '{ul' or '{ol' ([`Begin_list _]) is read. The only "valid" way to exit is by reading a [`Right_brace] token, which is consumed. Whitespace inside the list, but outside list items, is not significant – this parsing function consumes all of it. Otherwise, only list item start tokens are accepted. Everything else is an error. *) and explicit_list_items : parent_markup:[< Token.t ] -> input -> Ast.nestable_block_element with_location list list * Loc.span = fun ~parent_markup input -> let rec consume_list_items : Ast.nestable_block_element with_location list list -> Ast.nestable_block_element with_location list list * Loc.span = fun acc -> let next_token = peek input in match next_token.value with | `End -> Parse_error.end_not_allowed next_token.location ~in_what:(Token.describe parent_markup) |> add_warning input; (List.rev acc, next_token.location) | `Right_brace -> junk input; (List.rev acc, next_token.location) | `Space _ | `Single_newline _ | `Blank_line _ -> junk input; consume_list_items acc | `Begin_list_item kind as token -> junk input; (* '{li', represented by [`Begin_list_item `Li], must be followed by whitespace. *) (if kind = `Li then match (peek input).value with | `Space _ | `Single_newline _ | `Blank_line _ | `Right_brace -> () (* The presence of [`Right_brace] above requires some explanation: - It is better to be silent about missing whitespace if the next token is [`Right_brace], because the error about an empty list item will be generated below, and that error is more important to the user. - The [`Right_brace] token also happens to include all whitespace before it, as a convenience for the rest of the parser. As a result, not ignoring it could be wrong: there could in fact be whitespace in the concrete syntax immediately after '{li', just it is not represented as [`Space], [`Single_newline], or [`Blank_line]. *) | _ -> Parse_error.should_be_followed_by_whitespace next_token.location ~what:(Token.print token) |> add_warning input); let content, token_after_list_item, _where_in_line = block_element_list In_explicit_list ~parent_markup:token input in if content = [] then Parse_error.should_not_be_empty next_token.location ~what:(Token.describe token) |> add_warning input; (match token_after_list_item.value with | `Right_brace -> junk input | `End -> Parse_error.end_not_allowed token_after_list_item.location ~in_what:(Token.describe token) |> add_warning input); let acc = content :: acc in consume_list_items acc | token -> let suggestion = match token with | `Begin_section_heading _ | `Tag _ -> Printf.sprintf "move %s outside the list." (Token.describe token) | _ -> Printf.sprintf "move %s into a list item, %s or %s." (Token.describe token) (Token.print (`Begin_list_item `Li)) (Token.print (`Begin_list_item `Dash)) in Parse_error.not_allowed next_token.location ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion |> add_warning input; junk input; consume_list_items acc in consume_list_items [] (* Consumes a sequence of table rows that might start with [`Bar]. This function is called immediately after '{t' ([`Begin_table `Light]) is read. The only "valid" way to exit is by reading a [`Right_brace] token, which is consumed. *) and light_table ~parent_markup ~parent_markup_location input = let rec consume_rows acc ~last_loc = Reader.until_rbrace_or_eof input acc >>> fun next_token -> match next_token.Loc.value with | `Bar | #token_that_always_begins_an_inline_element -> ( let next, row, last_loc = light_table_row ~parent_markup ~last_loc input in match next with | `Continue -> consume_rows (row :: acc) ~last_loc | `Stop -> (row :: acc, last_loc)) | other_token -> Parse_error.not_allowed next_token.location ~what:(Token.describe other_token) ~in_what:(Token.describe parent_markup) |> add_warning input; junk input; consume_rows acc ~last_loc in let rows, brace_location = consume_rows [] ~last_loc:parent_markup_location in let grid = List.rev rows in (Table.Light_syntax.from_raw_data grid, brace_location) (* Consumes a table row that might start with [`Bar]. *) and light_table_row ~parent_markup ~last_loc input = let rec consume_row acc_row acc_cell acc_space ~new_line ~last_loc = let push_cells row cell = match cell with [] -> row | _ -> List.rev cell :: row in let return row cell = List.rev (push_cells row cell) in let next_token = peek input in match next_token.value with | `End -> Parse_error.end_not_allowed next_token.location ~in_what:"table" |> add_warning input; junk input; (`Stop, return acc_row acc_cell, next_token.location) | `Right_brace -> junk input; (`Stop, return acc_row acc_cell, next_token.location) | `Space _ as token -> junk input; let i = Loc.at next_token.location token in consume_row acc_row acc_cell (i :: acc_space) ~new_line ~last_loc | `Single_newline _ | `Blank_line _ -> junk input; (`Continue, return acc_row acc_cell, last_loc) | `Bar -> junk input; let acc_row = if new_line then [] else List.rev acc_cell :: acc_row in consume_row acc_row [] [] ~new_line:false ~last_loc | #token_that_always_begins_an_inline_element as token -> let i = inline_element input next_token.location token in if Loc.spans_multiple_lines i then Parse_error.not_allowed ~what:(Token.describe (`Single_newline "")) ~in_what:(Token.describe `Begin_table_light) i.location |> add_warning input; let acc_cell = if acc_cell = [] then [ i ] else (i :: acc_space) @ acc_cell in consume_row acc_row acc_cell [] ~new_line:false ~last_loc:next_token.location | other_token -> Parse_error.not_allowed next_token.location ~what:(Token.describe other_token) ~in_what:(Token.describe parent_markup) |> add_warning input; junk input; consume_row acc_row acc_cell acc_space ~new_line ~last_loc in consume_row [] [] [] ~new_line:true ~last_loc (* Consumes a sequence of table rows (starting with '{tr ...}', which are represented by [`Begin_table_row] tokens). This function is called immediately after '{table' ([`Begin_table `Heavy]) is read. The only "valid" way to exit is by reading a [`Right_brace] token, which is consumed. *) and heavy_table ~parent_markup ~parent_markup_location input = let rec consume_rows acc ~last_loc = Reader.until_rbrace_or_eof input acc >>> fun next_token -> match next_token.Loc.value with | `Begin_table_row as token -> junk input; let items, last_loc = heavy_table_row ~parent_markup:token input in consume_rows (List.rev items :: acc) ~last_loc | token -> Parse_error.not_allowed next_token.location ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion:"Move outside of {table ...}, or inside {tr ...}" |> add_warning input; junk input; consume_rows acc ~last_loc in let rows, brace_location = consume_rows [] ~last_loc:parent_markup_location in let grid = List.rev rows in (Table.Heavy_syntax.from_grid grid, brace_location) (* Consumes a sequence of table cells (starting with '{th ...}' or '{td ... }', which are represented by [`Begin_table_cell] tokens). This function is called immediately after '{tr' ([`Begin_table_row]) is read. The only "valid" way to exit is by reading a [`Right_brace] token, which is consumed. *) and heavy_table_row ~parent_markup input = let rec consume_cell_items acc = Reader.until_rbrace_or_eof input acc >>> fun next_token -> match next_token.Loc.value with | `Begin_table_cell kind as token -> junk input; let content, token_after_list_item, _where_in_line = block_element_list In_table_cell ~parent_markup:token input in (match token_after_list_item.value with | `Right_brace -> junk input | `End -> Parse_error.not_allowed token_after_list_item.location ~what:(Token.describe `End) ~in_what:(Token.describe token) |> add_warning input); consume_cell_items ((content, kind) :: acc) | token -> Parse_error.not_allowed next_token.location ~what:(Token.describe token) ~in_what:(Token.describe parent_markup) ~suggestion: "Move outside of {table ...}, or inside {td ...} or {th ...}" |> add_warning input; junk input; consume_cell_items acc in consume_cell_items [] (* {2 Entry point} *) let parse warnings tokens = let input : input = { tokens; warnings } in let rec parse_block_elements () = let elements, last_token, _where_in_line = block_element_list Top_level ~parent_markup:`Comment input in match last_token.value with | `End -> elements | `Right_brace -> Parse_error.unpaired_right_brace last_token.location |> add_warning input; let block = Loc.same last_token (`Paragraph [ Loc.same last_token (`Word "}") ]) in junk input; elements @ (block :: parse_block_elements ()) in let ast = parse_block_elements () in (ast, List.rev !(input.warnings))