AptConf

let eol = Util.eol

And Util.eol end of line

let empty = Util.empty_c_style

A C-style empty line

let indent = Util.indent

An indentation

let comment_simple = Util.comment_c_style

A one-line comment, C-style

let comment_multi = Util.comment_multiline

A multiline comment, C-style

let comment = comment_simple | comment_multi

A comment, either comment_simple or comment_multi

let name_re = /[A-Za-z][A-Za-z-]*/

Regex for entry names

let name_re_colons = /[A-Za-z][A-Za-z:-]*/

Regex for entry names with colons

let rec entry_noeol = let value = Util.del_str "\"" . store /[^"\n]+/ . del /";?/ "\";" in let opt_eol = del /[ \t\n]*/ "\n" in let long_eol = del /[ \t]*\n+/ "\n" in let list_elem = [ opt_eol . label "@elem" . value ] in let eol_comment = del /([ \t\n]*\n)?/ "" . comment in [ key name_re . Sep.space . value ] | [ key name_re . del /[ \t\n]*\{/ " {" . ( (opt_eol . entry_noeol) | list_elem | eol_comment )* . del /[ \t\n]*\};?/ "\n};" ] | [ key name_re . Util.del_str "::" . entry_noeol ]

An apt.conf entry, recursive

WARNING

This lens exploits a put ambiguity since apt.conf allows for both APT { Clean-Installed { “true” } } and APT::Clean-Installed “true”; but we’re chosing to map them the same way

The recursive lens doesn’t seem to care and defaults to the first item in the union.

This is why the APT { Clean-Installed { “true”; } } form is listed first, since it supports all subnodes (which Dpkg::Conf) doesn’t.

Exchanging these two expressions in the union makes tests fails since the tree cannot be mapped back.

This situation results in existing configuration being modified when the associated tree is modified.  For example, changing the value of APT::Clean-Installed “true”; to “false” results in APT { Clean-Installed “false”; }

(see unit tests)

let include = [ indent . key "#include" . Sep.space . store Rx.fspath . eol ]

A file inclusion /!\ The manpage is not clear on the syntax

let clear = let name = [ label "name" . store name_re_colons ] in [ indent . key "#clear" . Sep.space . Build.opt_list name Sep.space . eol ]

A list of variables to clear /!\ The manpage is not clear on the syntax

let lns = (empty|comment|entry|include|clear)*

The apt.conf lens