package fmlib_parse

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Module Make.Parser

The final parser.

A parser p is a sink of token. As long as it signals needs_more p more token can be pushed into the parser via put_token p or the input stream can be ended via put_end p.

has_result p is equivalent to not (needs_more p). has_result p signals that the parser has either succeeded or failed.

If it has succeeded the final value is available via final p.

There are two types of failure:

  • Syntax error: In that case failed_expectations p returns the list of failed expectations.
  • Semantic error: In that case failed_semantic p returns the encountered semantic error.

The function state returns the user state.

The function lookaheads returns a pair. The first part of the pair is an array of unprocessed lookahead token and the second part is a flag indicating if the endtoken has been received via put_end.

type token = Token.t

Token type.

type state = State.t

User state.

type final = Final.t

Type of the final object constructed in case of success.

type expect = Expect.t

Type of a failed expectation.

type semantic = Semantic.t

Type a semantic error.

type t

Type of the final parser.

val needs_more : t -> bool

needs_more p Does the parser p need more token?

val has_result : t -> bool

has_result p Has the parser p ended parsing and either succeeded or failed?

has_result p is the same as not (needs_more p)

val has_ended : t -> bool
  • deprecated

    Use has_result.

val has_received_end : t -> bool

has_received_end p Has the parser p already received the end of token stream via put_end?

val put : token -> t -> t

put token p Push token into the parser p.

Even if the parser has ended, more token can be pushed into the parser. The parser stores the token as lookahead token.

val put_end : t -> t

put_end p Push and end token into the parser p.

Precondition: not (has_received_end p)

val run_on_stream : token Stream.t -> t -> t

run_on_stream str p Run the parser p on the stream of tokens str.

val run_on_list : token list -> t -> t

run_on_list lst p Run the parser p on the list of tokens lst.

val has_succeeded : t -> bool

has_succeeded p Has the parser p succeeded?

val has_failed_syntax : t -> bool

has_failed_syntax p Has the parser p failed with a syntax error?

val has_failed_semantic : t -> bool

has_failed_semantic p Has the parser p failed with a semantic error?

val final : t -> final

final p The final object constructed by the parser p in case of success.

Precondition: has_succeeded p

val failed_expectations : t -> expect list

failed_expectations p The failed expectations due to a syntax error.

Precondition: has_failed_syntax p

val failed_semantic : t -> semantic

failed_semantic p The failed semantic error.

Precondition: has_failed_semantic p

val state : t -> state

state p The user state of the parser p.

Can be called at any time.

val has_lookahead : t -> bool

has_lookahead p Are there any unconsumed lookahead token in the buffer or has the end token not yet been consumed?

val lookaheads : t -> token array * bool

lookaheads p The lookahead token and and end flag of the parser p.

The end flag indicates that the end token has already been received via put_end p.