FLAN

A dot-file manager, inspired by Sheng Chen's Variational Typing. The idea is to use variational types to produce different dot-files depending on the configuration (i.e. a laptop or a desktop), avoiding the need to duplicating code. There are some extras bells and whistles for convenience, such as being able to declare variables and directly referencing envrionment variables.

USAGE

an example of a .gitconfig using a dimension to configure autocrlf:

# .gitconfig_generic
[user]
name = foo
email = foo@bar.com

[core]
autocrl = #os{false##true}#

then running from command line the following

$ cat .gitconfig_generic | flan os=0 --stdin
# .gitconfig_generic
[user]
name = foo
email = foo@bar.com

[core]
autocrl = false

The option os=0 indicates that for the dimension called os we chose the first choice (0-indexed). It is possible to give your choices names, by declaring your dimensions in a config file (by default .flan or specified with the --config option) as follow

[dimensions]
os = [ "windows", "linux"]

we can then call the choice by name

$ cat .gitconfig_generic | flan os=linux --stdin
# .gitconfig_generic
[user]
name = foo
email = foo@bar.com

[core]
autocrl = false

the full syntax:

Terms := Term*
Term  :=  #$IDENTIFIER#                      // variables
       |  #$$ENV_VAR#                        // environment variables
       | `#DIMID{` Terms (`##` Terms)* `}#`  // Dimensions
       |  Text                               // anything else

DIMID := (alpha | `_`)(alphanumeric | `_`)*
IDENTIFIER := (alphanumeric | [!%&'*+-./:<=>?@_])+

CONFIG

The configuration file uses a TOML syntax and the following things can be specified:

[options] # default command-line flags/options
force = false        # overwrite destination files
verbosity = 5        # see: `flan::cfg::ErrorFlags::report_level`
ignore_unset = false # ignores unset variables (will be substituted by blank string)
in-prefix = "./src/"     # prefix directory for input paths
out-prefix = "./dist/"    # prefix directory for output paths

[variables]
hostname = "foo"

[dimensions]
os = 2               # dimensions "os" with unnamed choices of size 2

[paths]
"source.conf" = "dest/ination.conf"  # source -> destination file mappings

TODO

• optimization (cf. Domination)
• error message in config file (currently fatal error: <toml parser error>)
• better inference
• on call-site/scoped dimension declaration