This lets us implement correct Unicode trimming and also simplifies the
parsing logic a bit. This also removes the last platform specific bits of
code in ripgrep core.
This commit does the work to delete the old `grep` crate and effectively
rewrite most of ripgrep core to use the new libripgrep crates. The new
`grep` crate is now a facade that collects the various crates that make
up libripgrep.
The most complex part of ripgrep core is now arguably the translation
between command line parameters and the library options, which is
ultimately where we want to be.
This commit adds support for reading configuration files that change
ripgrep's default behavior. The format of the configuration file is an
"rc" style and is very simple. It is defined by two rules:
1. Every line is a shell argument, after trimming ASCII whitespace.
2. Lines starting with '#' (optionally preceded by any amount of
ASCII whitespace) are ignored.
ripgrep will look for a single configuration file if and only if the
RIPGREP_CONFIG_PATH environment variable is set and is non-empty.
ripgrep will parse shell arguments from this file on startup and will
behave as if the arguments in this file were prepended to any explicit
arguments given to ripgrep on the command line.
For example, if your ripgreprc file contained a single line:
--smart-case
then the following command
RIPGREP_CONFIG_PATH=wherever/.ripgreprc rg foo
would behave identically to the following command
rg --smart-case foo
This commit also adds a new flag, --no-config, that when present will
suppress any and all support for configuration. This includes any future
support for auto-loading configuration files from pre-determined paths
(which this commit does not add).
Conflicts between configuration files and explicit arguments are handled
exactly like conflicts in the same command line invocation. That is,
this command:
RIPGREP_CONFIG_PATH=wherever/.ripgreprc rg foo --case-sensitive
is exactly equivalent to
rg --smart-case foo --case-sensitive
in which case, the --case-sensitive flag would override the --smart-case
flag.
Closes#196
