Add V implementation

.editorconfig

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+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.v]
+indent_style = tab
+indent_size = 4

v/syms.v

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+module main
+
+import os
+import flag
+import regex // FIXME: use POSIX regexs
+
+import v.vmod
+const manifest = vmod.from_file('v.mod') or { panic(err) }
+
+[noreturn]
+fn error_exit(code int, msg string) {
+	eprintln(msg)
+	exit(code)
+}
+
+fn main() {
+	mut fp := flag.new_flag_parser(os.args)
+	fp.application(manifest.name)
+	fp.version(manifest.version)
+	fp.description(manifest.description)
+	default_symbol := '[\\a\\A]+'
+	symbol := fp.string('symbol', `s`, default_symbol, 'symbols are given by REGEXP')
+	mut re := regex.regex_opt(symbol) or {
+		error_exit(1, 'invalid regex $symbol')
+	}
+	fp.footer('
+The default symbol type is words (-s "$default_symbol"); other useful settings include:
+
+  non-white-space characters: -s "[\\S]+"
+  alphanumerics and underscores: -s "\\w+"
+  XML tags: -s "<([\\a\\a_:][\\w:.-]*)[\\s>]"')
+	fp.skip_executable()
+
+	additional_args := fp.finalize() ?
+	for file in additional_args {
+		// FIXME: read one line at a time
+		lines := os.read_lines(file) or {
+			error_exit(1, 'cannot open \'$file\'')
+		}
+		for l in lines {
+			// FIXME: read one symbol at a time
+			for sym in re.find_all_str(l) {
+				println(sym)
+			}
+		}
+	}
+}

v/v.mod

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+Module {
+	name: 'syms'
+	description: 'List symbols in input'
+	version: '0.0.0'
+	license: 'GPLv3+'
+	dependencies: []
+}