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|
const std = @import("std");
pub const Grammar = @import("grammar.zig");
fn help(err: ?anyerror) noreturn {
const stderr = std.io.getStdErr().writer();
if (err) |e| {
stderr.print("error: {s}\n", .{@errorName(e)}) catch unreachable;
}
stderr.writeAll(
\\mry [command] [options]
\\
\\Commands:
\\
\\ generate [grammar] [options]
\\ Options:
\\ -o, --output entry Output string to file
\\ By default stdout will be used.
\\
\\ -c, --count n Number of texts to generate. (default: 1)
\\
\\ -n, --non-empty Only output texts which are non-empty.
\\
\\ recognize [grammar] [options]
\\ Options:
\\ -i, --input entry Specify input source, if the path
\\ points to a directory it will scan
\\ all files in it. By default stdin will
\\ be used as input.
\\
\\General Options
\\ -h, --help Print usage
\\
) catch unreachable;
std.process.exit(@intFromBool(err != null));
}
fn check(arg_or_null: ?[]const u8) []const u8 {
const arg = arg_or_null orelse help(error.MissingArgument);
if (std.mem.eql(u8, arg, "-h") or std.mem.eql(u8, arg, "--help")) {
help(null);
}
return arg;
}
fn parse_enum(T: type, arg: []const u8) T {
return std.meta.stringToEnum(T, arg) orelse help(error.InvalidArgument);
}
fn parse_int(n: []const u8) usize {
return std.fmt.parseInt(usize, n, 10) catch |e| help(e);
}
fn check_flags(arg: []const u8, comptime flags: []const []const u8) bool {
inline for (flags) |flag| {
if (std.mem.eql(u8, arg, flag)) {
return true;
}
}
return false;
}
pub const Mode = enum {
recognize,
generate,
};
pub const Entry = struct {
const Self = @This();
name: []const u8,
file: std.fs.File,
pub fn open(path: []const u8, flags: std.fs.File.OpenFlags) Self {
var cwd = std.fs.cwd();
return Self {
.name = path,
.file = cwd.openFile(path, flags) catch |e| help(e)
};
}
pub fn read_file(path: []const u8, allocator: std.mem.Allocator) []const u8 {
var cwd = std.fs.cwd();
var file = cwd.openFile(path, .{}) catch |e| help(e);
defer file.close();
const stat = file.stat() catch |e| help(e);
return file.readToEndAlloc(allocator, stat.size) catch |e| help(e);
}
pub fn stdin() Self {
return Self {
.name = "[stdin]",
.file = std.io.getStdIn(),
};
}
pub fn stdout() Self {
return Self {
.name = "[stdout]",
.file = std.io.getStdOut(),
};
}
};
pub const RecognizeArgs = struct {
input: Entry,
grammar: Grammar,
};
pub const GenerateArgs = struct {
count: usize,
empty: bool,
output: Entry,
grammar: Grammar,
};
pub const Args = union(Mode) {
const Self = @This();
recognize: RecognizeArgs,
generate: GenerateArgs,
pub fn parse(allocator: std.mem.Allocator) Self {
var args = std.process.args();
_ = args.next();
const mode = parse_enum(Mode, check(args.next()));
const text = Entry.read_file(check(args.next()), allocator);
defer allocator.free(text);
const grammar = Grammar.parse(
text,
allocator
) catch |e| help(e);
switch (mode) {
.recognize => {
var input: ?Entry = null;
while (args.next()) |arg| {
if (check_flags(arg, &[_][]const u8 { "-i", "--input" })) {
input = Entry.open(check(args.next()), .{});
} else help(error.InvalidArgument);
}
return Self {
.recognize = .{
.input = input orelse Entry.stdin(),
.grammar = grammar,
},
};
},
.generate => {
var count: usize = 1;
var output: ?Entry = null;
var empty: bool = true;
while (args.next()) |arg| {
if (check_flags(arg, &[_][]const u8 { "-o", "--output" })) {
output = Entry.open(check(args.next()), .{ .mode = .write_only });
} else if (check_flags(arg, &[_][]const u8 { "-c", "--count" })) {
count = parse_int(check(args.next()));
} else if (check_flags(arg, &[_][]const u8 { "-n", "--non-empty" })) {
empty = false;
} else help(error.InvalidArgument);
}
return Self {
.generate = .{
.count = count,
.empty = empty,
.output = output orelse Entry.stdout(),
.grammar = grammar,
},
};
},
}
}
pub fn deinit(self: *Self, allocator: std.mem.Allocator) void {
switch (self.*) {
.recognize => |*rec| {
rec.grammar.deinit(allocator);
},
.generate => |*gen| {
gen.grammar.deinit(allocator);
}
}
}
};
|
