Parsing0.Misc
Miscellaneous useful types and functions
Warning: this module is unstable and part of compiler-libs.
let fatal_errorf: format4('a, Format.formatter, unit, 'b) => 'a;
try_finally work ~always ~exceptionally
is designed to run code in work
that may fail with an exception, and has two kind of cleanup routines: always
, that must be run after any execution of the function (typically, freeing system resources), and exceptionally
, that should be run only if work
or always
failed with an exception (typically, undoing user-visible state changes that would only make sense if the function completes correctly). For example:
let objfile = outputprefix ^ ".cmo" in
let oc = open_out_bin objfile in
Misc.try_finally
(fun () ->
bytecode
++ Timings.(accumulate_time (Generate sourcefile))
(Emitcode.to_file oc modulename objfile);
Warnings.check_fatal ())
~always:(fun () -> close_out oc)
~exceptionally:(fun _exn -> remove_file objfile);
If exceptionally
fail with an exception, it is propagated as usual.
If always
or exceptionally
use exceptions internally for control-flow but do not raise, then try_finally
is careful to preserve any exception backtrace coming from work
or always
for easier debugging.
reraise_preserving_backtrace e f
is (f (); raise e) except that the current backtrace is preserved, even if f
uses exceptions internally.
let protect_refs: list(ref_and_value) => (unit => 'a) => 'a;
protect_refs l f
temporarily sets r
to v
for each R (r, v)
in l
while executing f
. The previous contents of the references is restored even if f
raises an exception, without altering the exception backtrace.
module Stdlib: { ... };
let create_hashtable: int => list(('a, 'b)) => Hashtbl.t('a, 'b);
let copy_file: in_channel => out_channel => unit;
let copy_file_chunk: in_channel => out_channel => int => unit;
let string_of_file: in_channel => string;
let output_to_bin_file_directly: string => (string => out_channel => 'a) => 'a;
let output_to_file_via_temporary:
?mode:list(open_flag) =>
string =>
(string => out_channel => 'a) =>
'a;
let protect_writing_to_file: filename:string => f:(out_channel => 'a) => 'a;
Open the given filename
for writing (in binary mode), pass the out_channel
to the given function, then close the channel. If the function raises an exception then filename
will be removed.
module Int_literal_converter: { ... };
let get_ref: ref(list('a)) => list('a);
let set_or_ignore: ('a => option('b)) => ref(option('b)) => 'a => unit;
module LongString: { ... };
edit_distance a b cutoff
computes the edit distance between strings a
and b
. To help efficiency, it uses a cutoff: if the distance d
is smaller than cutoff
, it returns Some d
, else None
.
The distance algorithm currently used is Damerau-Levenshtein: it computes the number of insertion, deletion, substitution of letters, or swapping of adjacent letters to go from one word to the other. The particular algorithm may change in the future.
spellcheck env name
takes a list of names env
that exist in the current environment and an erroneous name
, and returns a list of suggestions taken from env
, that are close enough to name
that it may be a typo for one of them.
let did_you_mean: Format.formatter => (unit => list(string)) => unit;
did_you_mean ppf get_choices
hints that the user may have meant one of the option returned by calling get_choices
. It does nothing if the returned list is empty.
The unit -> ...
thunking is meant to delay any potentially-slow computation (typically computing edit-distance with many things from the current environment) to when the hint message is to be printed. You should print an understandable error message before calling did_you_mean
, so that users get a clear notification of the failure even if producing the hint is slow.
String.cut_at s c
returns a pair containing the sub-string before the first occurrence of c
in s
, and the sub-string after the first occurrence of c
in s
. let (before, after) = String.cut_at s c in
before ^ String.make 1 c ^ after
is the identity if s
contains c
.
Raise Not_found
if the character does not appear in the string
ordinal_suffix n
is the appropriate suffix to append to the numeral n
as an ordinal number: 1
-> "st"
, 2
-> "nd"
, 3
-> "rd"
, 4
-> "th"
, and so on. Handles larger numbers (e.g., 42
-> "nd"
) and the numbers 11--13 (which all get "th"
) correctly.
module Color: { ... };
module Error_style: { ... };
normalise_eol s
returns a fresh copy of s
with any '\r' characters removed. Intended for pre-processing text which will subsequently be printed on a channel which performs EOL transformations (i.e. Windows)
delete_eol_spaces s
returns a fresh copy of s
with any end of line spaces removed. Intended to normalize the output of the toplevel for tests.
let pp_two_columns:
?sep:string =>
?max_lines:int =>
Format.formatter =>
list((string, string)) =>
unit;
pp_two_columns ?sep ?max_lines ppf l
prints the lines in l
as two columns separated by sep
("|" by default). max_lines
can be used to indicate a maximum number of lines to print -- an ellipsis gets inserted at the middle if the input has too many lines.
Example:
pp_two_columns ~max_lines:3 Format.std_formatter [ "abc", "hello"; "def", "zzz"; "a" , "bllbl"; "bb" , "dddddd"; ]
prints
abc | hello ... bb | dddddd
Returns the map encoded in the BUILD_PATH_PREFIX_MAP
environment variable.
Returns the list of --debug-prefix-map
flags to be passed to the assembler, built from the BUILD_PATH_PREFIX_MAP
environment variable.
let print_if:
Format.formatter =>
ref(bool) =>
(Format.formatter => 'a => unit) =>
'a =>
'a;
print_if ppf flag fmt x
prints x
with fmt
on ppf
if b
is true.
type alerts = Stdlib.String.Map.t(string);
module Magic_number: { ... };
a typical magic number is "Caml1999I011"; it is formed of an alphanumeric prefix, here Caml1990I, followed by a version, here 011. The prefix identifies the kind of the versioned data: here the I indicates that it is the magic number for .cmi files.