app.rs

use std::collections::HashMap;

use clap::{App, AppSettings, Arg};

const ABOUT: &'static str = "
ripgrep (rg) recursively searches your current directory for a regex pattern.

Project home page: https://github.com/BurntSushi/ripgrep

Use -h for short descriptions and --help for more details.";

const USAGE: &'static str = "
    rg [OPTIONS] <pattern> [<path> ...]
    rg [OPTIONS] [-e PATTERN | -f FILE ]... [<path> ...]
    rg [OPTIONS] --files [<path> ...]
    rg [OPTIONS] --type-list";

const TEMPLATE: &'static str = "\
{bin} {version}
{author}
{about}

USAGE:{usage}

ARGS:
{positionals}

OPTIONS:
{unified}";

/// Build a clap application with short help strings.
pub fn app_short() -> App<'static, 'static> {
    app(false, |k| USAGES[k].short)
}

/// Build a clap application with long help strings.
pub fn app_long() -> App<'static, 'static> {
    app(true, |k| USAGES[k].long)
}

/// Build a clap application parameterized by usage strings.
///
/// The function given should take a clap argument name and return a help
/// string. `app` will panic if a usage string is not defined.
///
/// This is an intentionally stand-alone module so that it can be used easily
/// in a `build.rs` script to build shell completion files.
fn app<F>(next_line_help: bool, doc: F) -> App<'static, 'static>
        where F: Fn(&'static str) -> &'static str {
    let arg = |name| {
        Arg::with_name(name).help(doc(name)).next_line_help(next_line_help)
    };
    let flag = |name| arg(name).long(name);

    App::new("ripgrep")
        .author(crate_authors!())
        .version(crate_version!())
        .about(ABOUT)
        .max_term_width(100)
        .setting(AppSettings::UnifiedHelpMessage)
        .usage(USAGE)
        .template(TEMPLATE)
        // Handle help/version manually to make their output formatting
        // consistent with short/long views.
        .arg(arg("help-short").short("h"))
        .arg(flag("help"))
        .arg(flag("version").short("V"))
        // First, set up primary positional/flag arguments.
        .arg(arg("pattern")
             .required_unless_one(&[
                "file", "files", "help-short", "help", "regexp", "type-list",
                "version",
             ]))
        .arg(arg("path").multiple(true))
        .arg(flag("regexp").short("e")
             .takes_value(true).multiple(true).number_of_values(1)
             .value_name("pattern"))
        .arg(flag("files")
             // This should also conflict with `pattern`, but the first file
             // path will actually be in `pattern`.
             .conflicts_with_all(&["file", "regexp", "type-list"]))
        .arg(flag("type-list")
             .conflicts_with_all(&["file", "files", "pattern", "regexp"]))
        // Second, set up common flags.
        .arg(flag("text").short("a"))
        .arg(flag("count").short("c"))
        .arg(flag("color")
             .value_name("WHEN")
             .takes_value(true)
             .hide_possible_values(true)
             .possible_values(&["never", "always", "auto"]))
        .arg(flag("fixed-strings").short("F"))
        .arg(flag("glob").short("g")
             .takes_value(true).multiple(true).number_of_values(1)
             .value_name("GLOB"))
        .arg(flag("ignore-case").short("i"))
        .arg(flag("line-number").short("n"))
        .arg(flag("no-line-number").short("N"))
        .arg(flag("quiet").short("q"))
        .arg(flag("type").short("t")
             .takes_value(true).multiple(true).number_of_values(1)
             .value_name("TYPE"))
        .arg(flag("type-not").short("T")
             .takes_value(true).multiple(true).number_of_values(1)
             .value_name("TYPE"))
        .arg(flag("unrestricted").short("u")
             .multiple(true))
        .arg(flag("invert-match").short("v"))
        .arg(flag("word-regexp").short("w"))
        // Third, set up less common flags.
        .arg(flag("after-context").short("A")
             .value_name("NUM").takes_value(true)
             .validator(validate_number))
        .arg(flag("before-context").short("B")
             .value_name("NUM").takes_value(true)
             .validator(validate_number))
        .arg(flag("context").short("C")
             .value_name("NUM").takes_value(true)
             .validator(validate_number))
        .arg(flag("column"))
        .arg(flag("context-separator").value_name("ARG").takes_value(true))
        .arg(flag("debug"))
        .arg(flag("file").short("f")
             .value_name("FILE").takes_value(true)
             .multiple(true).number_of_values(1))
        .arg(flag("files-with-matches").short("l"))
        .arg(flag("files-without-match"))
        .arg(flag("with-filename").short("H"))
        .arg(flag("no-filename"))
        .arg(flag("heading"))
        .arg(flag("no-heading"))
        .arg(flag("hidden"))
        .arg(flag("ignore-file")
             .value_name("FILE").takes_value(true)
             .multiple(true).number_of_values(1))
        .arg(flag("follow").short("L"))
        .arg(flag("max-count")
             .short("m").value_name("NUM").takes_value(true)
             .validator(validate_number))
        .arg(flag("maxdepth")
             .value_name("NUM").takes_value(true)
             .validator(validate_number))
        .arg(flag("mmap"))
        .arg(flag("no-messages"))
        .arg(flag("no-mmap"))
        .arg(flag("no-ignore"))
        .arg(flag("no-ignore-parent"))
        .arg(flag("no-ignore-vcs"))
        .arg(flag("null"))
        .arg(flag("pretty").short("p"))
        .arg(flag("replace").short("r").value_name("ARG").takes_value(true))
        .arg(flag("case-sensitive").short("s"))
        .arg(flag("smart-case").short("S"))
        .arg(flag("threads")
             .short("j").value_name("ARG").takes_value(true)
             .validator(validate_number))
        .arg(flag("vimgrep"))
        .arg(flag("type-add")
             .value_name("TYPE").takes_value(true)
             .multiple(true).number_of_values(1))
        .arg(flag("type-clear")
             .value_name("TYPE").takes_value(true)
             .multiple(true).number_of_values(1))
}

struct Usage {
    short: &'static str,
    long: &'static str,
}

macro_rules! doc {
    ($map:expr, $name:expr, $short:expr) => {
        doc!($map, $name, $short, $short)
    };
    ($map:expr, $name:expr, $short:expr, $long:expr) => {
        $map.insert($name, Usage {
            short: $short,
            long: concat!($long, "\n "),
        });
    };
}

lazy_static! {
    static ref USAGES: HashMap<&'static str, Usage> = {
        let mut h = HashMap::new();
        doc!(h, "help-short",
             "Show short help output.",
             "Show short help output. Use --help to show more details.");
        doc!(h, "help",
             "Show verbose help output.",
             "When given, more details about flags are provided.");
        doc!(h, "version",
             "Prints version information.");

        doc!(h, "pattern",
             "A regular expression used for searching.",
             "A regular expression used for searching. Multiple patterns \
              may be given. To match a pattern beginning with a -, use [-].");
        doc!(h, "regexp",
             "A regular expression used for searching.",
             "A regular expression used for searching. Multiple patterns \
              may be given. To match a pattern beginning with a -, use [-].");
        doc!(h, "path",
             "A file or directory to search.",
             "A file or directory to search. Directories are searched \
              recursively.");
        doc!(h, "files",
             "Print each file that would be searched.",
             "Print each file that would be searched without actually \
              performing the search. This is useful to determine whether a \
              particular file is being searched or not.");
        doc!(h, "type-list",
             "Show all supported file types.",
             "Show all supported file types and their corresponding globs.");

        doc!(h, "text",
             "Search binary files as if they were text.");
        doc!(h, "count",
             "Only show count of matches for each file.");
        doc!(h, "color",
             "When to use color. [default: auto]",
             "When to use color in the output. The possible values are \
              never, always or auto. The default is auto.");
        doc!(h, "fixed-strings",
             "Treat the pattern as a literal string.",
             "Treat the pattern as a literal string instead of a regular \
              expression. When this flag is used, special regular expression \
              meta characters such as (){}*+. do not need to be escaped.");
        doc!(h, "glob",
             "Include or exclude files/directories.",
             "Include or exclude files/directories for searching that \
              match the given glob. This always overrides any other \
              ignore logic. Multiple glob flags may be used. Globbing \
              rules match .gitignore globs. Precede a glob with a ! \
              to exclude it.");
        doc!(h, "ignore-case",
             "Case insensitive search.",
             "Case insensitive search. This is overridden by \
              --case-sensitive.");
        doc!(h, "line-number",
             "Show line numbers.",
             "Show line numbers (1-based). This is enabled by default when \
              searching in a tty.");
        doc!(h, "no-line-number",
             "Suppress line numbers.",
             "Suppress line numbers. This is enabled by default when NOT \
              searching in a tty.");
        doc!(h, "quiet",
             "Do not print anything to stdout.",
             "Do not print anything to stdout. If a match is found in a file, \
              stop searching. This is useful when ripgrep is used only for \
              its exit code.");
        doc!(h, "type",
             "Only search files matching TYPE.",
             "Only search files matching TYPE. Multiple type flags may be \
              provided. Use the --type-list flag to list all available \
              types.");
        doc!(h, "type-not",
             "Do not search files matching TYPE.",
             "Do not search files matching TYPE. Multiple type-not flags may \
              be provided. Use the --type-list flag to list all available \
              types.");
        doc!(h, "unrestricted",
             "Reduce the level of \"smart\" searching.",
             "Reduce the level of \"smart\" searching. A single -u \
              won't respect .gitignore (etc.) files. Two -u flags will \
              additionally search hidden files and directories. Three \
              -u flags will additionally search binary files. -uu is \
              roughly equivalent to grep -r and -uuu is roughly \
              equivalent to grep -a -r.");
        doc!(h, "invert-match",
             "Invert matching.",
             "Invert matching. Show lines that don't match given patterns.");
        doc!(h, "word-regexp",
             "Only show matches surrounded by word boundaries.",
             "Only show matches surrounded by word boundaries. This is \
              equivalent to putting \\b before and after all of the search \
              patterns.");

        doc!(h, "after-context",
             "Show NUM lines after each match.");
        doc!(h, "before-context",
             "Show NUM lines before each match.");
        doc!(h, "context",
             "Show NUM lines before and after each match.");
        doc!(h, "column",
             "Show column numbers",
             "Show column numbers (1-based). This only shows the column \
              numbers for the first match on each line. This does not try \
              to account for Unicode. One byte is equal to one column.");
        doc!(h, "context-separator",
             "Set the context separator string. [default: --]",
             "The string used to separate non-contiguous context lines in the \
              output. Escape sequences like \\x7F or \\t may be used. The \
              default value is --.");
        doc!(h, "debug",
             "Show debug messages.",
             "Show debug messages. Please use this when filing a bug report.");
        doc!(h, "file",
             "Search for patterns from the given file.",
             "Search for patterns from the given file, with one pattern per \
              line. When this flag is used or multiple times or in \
              combination with the -e/--regexp flag, then all patterns \
              provided are searched. Empty pattern lines will match all input \
              lines, and the newline is not counted as part of the pattern.");
        doc!(h, "files-with-matches",
             "Only show the path of each file with at least one match.");
        doc!(h, "files-without-match",
             "Only show the path of each file that contains zero matches.");
        doc!(h, "with-filename",
             "Show file name for each match.",
             "Prefix each match with the file name that contains it. This is \
              the default when more than one file is searched.");
        doc!(h, "no-filename",
             "Never show the file name for a match.",
             "Never show the file name for a match. This is the default when \
              one file is searched.");
        doc!(h, "heading",
             "Show matches grouped by each file.",
             "This shows the file name above clusters of matches from each \
              file. This is the default mode at a tty.");
        doc!(h, "no-heading",
             "Don't group matches by each file.",
             "Don't group matches by each file. This is the default mode \
              when not at a tty.");
        doc!(h, "hidden",
             "Search hidden files and directories.",
             "Search hidden files and directories. By default, hidden files \
              and directories are skipped.");
        doc!(h, "ignore-file",
             "Specify additional ignore files.",
             "Specify additional ignore files for filtering file paths. \
              Ignore files should be in the gitignore format and are matched \
              relative to the current working directory. These ignore files \
              have lower precedence than all other ignore files. When \
              specifying multiple ignore files, earlier files have lower \
              precedence than later files.");
        doc!(h, "follow",
             "Follow symbolic links.");
        doc!(h, "max-count",
             "Limit the number of matches.",
             "Limit the number of matching lines per file searched to NUM.");
        doc!(h, "maxdepth",
             "Descend at most NUM directories.",
             "Limit the depth of directory traversal to NUM levels beyond \
              the paths given. A value of zero only searches the \
              starting-points themselves.\n\nFor example, \
              'rg --maxdepth 0 dir/' is a no-op because dir/ will not be \
              descended into. 'rg --maxdepth 1 dir/' will search only the \
              direct children of dir/.");
        doc!(h, "mmap",
             "Searching using memory maps when possible.",
             "Search using memory maps when possible. This is enabled by \
              default when ripgrep thinks it will be faster. Note that memory \
              map searching doesn't currently support all options, so if an \
              incompatible option (e.g., --context) is given with --mmap, \
              then memory maps will not be used.");
        doc!(h, "no-messages",
             "Suppress all error messages.",
             "Suppress all error messages. This is equivalent to redirecting \
              stderr to /dev/null.");
        doc!(h, "no-mmap",
             "Never use memory maps.",
             "Never use memory maps, even when they might be faster.");
        doc!(h, "no-ignore",
             "Don't respect ignore files.",
             "Don't respect ignore files (.gitignore, .ignore, etc.). This \
              implies --no-ignore-parent and --no-ignore-vcs.");
        doc!(h, "no-ignore-parent",
             "Don't respect ignore files in parent directories.",
             "Don't respect ignore files (.gitignore, .ignore, etc.) in \
              parent directories.");
        doc!(h, "no-ignore-vcs",
             "Don't respect VCS ignore files",
             "Don't respect version control ignore files (.gitignore, etc.). \
              This implies --no-ignore-parent. Note that .ignore files will \
              continue to be respected.");
        doc!(h, "null",
             "Print NUL byte after file names",
             "Whenever a file name is printed, follow it with a NUL byte. \
              This includes printing file names before matches, and when \
              printing a list of matching files such as with --count, \
              --files-with-matches and --files. This option is useful for use \
              with xargs.");
        doc!(h, "pretty",
             "Alias for --color always --heading -n.");
        doc!(h, "replace",
             "Replace matches with string given.",
             "Replace every match with the string given when printing \
              results. Neither this flag nor any other flag will modify your \
              files.\n\nCapture group indices (e.g., $5) and names \
              (e.g., $foo) are supported in the replacement string.");
        doc!(h, "case-sensitive",
             "Search case sensitively.",
             "Search case sensitively. This overrides -i/--ignore-case and \
              -S/--smart-case.");
        doc!(h, "smart-case",
             "Smart case search.",
             "Searches case insensitively if the pattern is all lowercase. \
              Search case sensitively otherwise. This is overridden by \
              either -s/--case-sensitive or -i/--ignore-case.");
        doc!(h, "threads",
             "The approximate number of threads to use.",
             "The approximate number of threads to use. A value of 0 (which \
              is the default) causes ripgrep to choose the thread count \
              using heuristics.");
        doc!(h, "vimgrep",
             "Show results in vim compatible format.",
             "Show results with every match on its own line, including \
              line numbers and column numbers. With this option, a line with \
              more than one match will be printed more than once.");

        doc!(h, "type-add",
             "Add a new glob for a file type.",
             "Add a new glob for a particular file type. Only one glob can be \
              added at a time. Multiple --type-add flags can be provided. \
              Unless --type-clear is used, globs are added to any existing \
              globs defined inside of ripgrep.\n\nNote that this MUST be \
              passed to every invocation of ripgrep. Type settings are NOT \
              persisted.\n\nExample: \
              rg --type-add 'foo:*.foo' -tfoo PATTERN.");
        doc!(h, "type-clear",
             "Clear globs for given file type.",
             "Clear the file type globs previously defined for TYPE. This \
              only clears the default tpye definitions that are found inside \
              of ripgrep.\n\nNote that this MUST be passed to every \
              invocation of ripgrep. Type settings are NOT persisted.");

        h
    };
}

fn validate_number(s: String) -> Result<(), String> {
    s.parse::<usize>().map(|_|()).map_err(|err| err.to_string())
}