erl_parse
MODULE
MODULE SUMMARY
DESCRIPTION
This module is the basic Erlang parser which converts tokens into the abstract form of either forms (i.e., top-level constructs), expressions, or terms. The Abstract Format is described in the ERTS User's Guide. Note that a token list must end with the dot token in order to be acceptable to the parse functions (see erl_scan).
EXPORTS
parse_form(Tokens) -> {ok, AbsForm} | {error, ErrorInfo}
Types:
This function parses Tokens as if it were a form. It returns:
- {ok, AbsForm}
-
The parsing was successful. AbsForm is the abstract form of the parsed form.
- {error, ErrorInfo}
-
An error occurred.
parse_exprs(Tokens) -> {ok, Expr_list} | {error, ErrorInfo}
Types:
This function parses Tokens as if it were a list of expressions. It returns:
- {ok, Expr_list}
-
The parsing was successful. Expr_list is a list of the abstract forms of the parsed expressions.
- {error, ErrorInfo}
-
An error occurred.
parse_term(Tokens) -> {ok, Term} | {error, ErrorInfo}
Types:
This function parses Tokens as if it were a term. It returns:
- {ok, Term}
-
The parsing was successful. Term is the Erlang term corresponding to the token list.
- {error, ErrorInfo}
-
An error occurred.
format_error(ErrorDescriptor) -> Chars
Types:
Uses an ErrorDescriptor and returns a string which describes the error. This function is usually called implicitly when an ErrorInfo structure is processed (see below).
tokens(AbsTerm) -> Tokens
tokens(AbsTerm, MoreTokens) -> Tokens
Types:
This function generates a list of tokens representing the abstract form AbsTerm of an expression. Optionally, it appends Moretokens.
Types:
Converts the abstract form AbsTerm of a term into a conventional Erlang data structure (i.e., the term itself). This is the inverse of abstract/1.
Types:
Converts the Erlang data structure Data into an abstract form of type AbsTerm. This is the inverse of normalise/1.
Error Information
The ErrorInfo mentioned above is the standard ErrorInfo structure which is returned from all IO modules. It has the format:
{ErrorLine, Module, ErrorDescriptor}
A string which describes the error is obtained with the following call:
apply(Module, format_error, ErrorDescriptor)
See Also
io(3), erl_scan(3), ERTS User's Guide