The Egel Language
DIR home1: #!/usr/local/bin/egel 2: 3: # This program is free software: you can redistribute it and/or modify 4: # it under the terms of the GNU General Public License as published by 5: # the Free Software Foundation, either version 3 of the License, or (at 6: # your option) any later version. 7: # 8: # This program is distributed in the hope that it will be useful, but 9: # WITHOUT ANY WARRANTY; without even the implied warranty of 10: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11: # General Public License for more details. 12: # 13: # You should have received a copy of the GNU General Public License 14: # along with this program. If not, see <http://www.gnu.org/licenses/>. 15: 16: import "prelude.eg" 17: import "dictionary.eg" 18: 19: using System 20: using List 21: 22: def main = Serf::start 23: 24: namespace Serf ( 25: 26: def start = 27: if elem "start" args then start_servers 28: else if elem "gopher" args then serve_gopher_request 29: else if elem "www" args then serve_www_request 30: else if elem "debug" args then debug 31: else print "Usage: serf.eg [start|gopher|www|debug]\n" 32: 33: def start_gopher_server = 34: OS::exec "while true ; do nc -w 5 -4 -l 192.168.2.7 1470 -c \"egel serf.eg gopher\"; sleep 1 ; done" 35: 36: def start_www_server = 37: OS::exec "while true ; do nc -w 5 -4 -l 192.168.2.7 1480 -c \"egel serf.eg www\"; sleep 1 ; done" 38: 39: def start_servers = 40: let S0 = async [_ -> start_gopher_server] in 41: let S1 = async [_ -> start_www_server] in 42: await S0; await S1 43: ) 44: 45: namespace Serf ( 46: def serve_gopher_request = serve_selector ((OS::read_line OS::stdin) |> trim_crlf |> trim_lead) 47: 48: def trim_crlf = do String::to_chars |> break [C -> or (C == '\n') (C == '\r')] |> fst |> String::from_chars 49: 50: def trim_lead = [ S -> if String::starts_with "/" S then String::remove 0 1 S else S ] 51: 52: def split_lines = Regex::split (Regex::compile "\n") 53: 54: def serve_selector = do db_page |> to_gopher |> [T -> print T] 55: 56: def gopher_line = 57: [S -> "i" + S + "\tfake\t(NULL)\t0\r\n"] 58: 59: def code_numbers = 60: do split_lines 61: |> [LL -> zip_with (+) (map [N -> format " {:4}: " N] (from_to 1 (length LL + 1))) LL] 62: 63: def to_gopher = 64: [{} -> "" |{X|XX} -> to_gopher X + to_gopher XX 65: |(h0 S) -> gopher_line ("# " + S) 66: |(h1 S) -> gopher_line ("## " + S) 67: |(h2 S) -> gopher_line ("### " + S) 68: |(line S) -> gopher_line S 69: |hr -> gopher_line "" 70: |(code S) -> map gopher_line (code_numbers S) |> foldr (+) "" 71: |(link S T) -> "1" + S + "\t/" + T + "\tgopher.egel.dev\t70\r\n" 72: |(url S T) -> "h" + S + "\tURL:" + T + "\tgopher.egel.dev\t70\r\n" ] 73: ) 74: 75: namespace Serf ( 76: 77: def to_request = do Regex::split (Regex::compile " ") |> [{V,U|_} -> (V, trim_lead U)| _ -> none] 78: 79: def serve_www_request = serve_verb ((OS::read_line OS::stdin) |> trim_crlf |> to_request) 80: 81: def serve_verb = 82: [("GET", URL) -> if db_has URL then db_page URL |> to_html |> serve_page else serve_verb none 83: |_ -> db_unknown |> to_html |> serve_lost ] 84: 85: def serve_page = 86: [ T -> 87: print "HTTP/1.1 200 OK\r\n"; 88: print "Content-Type: text/html\r\n\r\n"; 89: print_html T ] 90: 91: def serve_lost = 92: [ T -> 93: print "HTTP/1.1 404 Not Found\r\n"; 94: print "Content-Type: text/html\r\n\r\n"; 95: print_html T ] 96: 97: def print_html = 98: [T -> 99: print "<!DOCTYPE html>"; 100: print "<html dir=\"ltr\">\n"; 101: print html_header; 102: print "<body><pre>" T "</pre></body>\n"; 103: print "</html>\n" ] 104: 105: def html_header = """ 106: <head> 107: <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> 108: <title>The Egel Language</title> 109: <style type="text/css"> 110: a { text-decoration: none; } a:hover { text-decoration: underline; } 111: pre { overflow: auto; } 112: @media (prefers-color-scheme: dark) { body { background-color: #000; color: #bdbdbd; color-scheme: dark; } a { color: #56c8ff; } } 113: </style> 114: <meta content="width=device-width" name="viewport" /> 115: </head> 116: """ 117: 118: def html_escape = do Regex::replace_all (Regex::compile "&") "&" |> Regex::replace_all (Regex::compile "<") "<" 119: 120: def to_html = 121: [{} -> "" |{X|XX} -> to_html X + to_html XX 122: |(h0 S) -> "<h1>" + S + "</h1>\n" 123: |(h1 S) -> " <b>" + S + "</b>\n" 124: |(h2 S) -> " <i>" + S + "</i>\n" 125: |hr -> "\n" 126: |(line S) -> " " + S + "\n" 127: |(code S) -> " <pre><code>" + (foldr [S0 S1 -> S0 + "\n" + S1] "" (code_numbers (html_escape S))) + "</code></pre>\n" 128: |(link S T) -> " DIR <a href=\"/" + T + "\">" + S + "</a>\n" 129: |(url S T) -> " HTML <a href=\"" + T + "\">" + S + "</a>\n"] 130: ) 131: 132: namespace Serf ( 133: 134: def debug = map [K -> print "selector: " K "\n"; print (to_txt (db_page K))] db_keys; none 135: 136: def to_txt = 137: [{} -> "" |{X|XX} -> to_txt X + "\n" + to_txt XX 138: |(h0 S) -> "# " + S + "\n" 139: |(h1 S) -> "## " + S + "\n" 140: |(h2 S) -> "### " + S + "\n" 141: |hr -> "\n" 142: |(line S) -> S + "\n" 143: |(code S) -> S + "\n" 144: |(link S T) -> S + " -> " + T 145: |(url S T) -> S + " => " + T ] 146: ) 147: 148: namespace Serf ( 149: data h0, h1, h2, line, hr, code, link, url, action 150: 151: val db = Dict::from_list db_pages 152: 153: def db_has = Dict::has db 154: 155: def db_get = Dict::get db 156: 157: def db_keys = db_pages |> map fst 158: 159: def db_subs = [K -> 160: db_keys |> filter (String::starts_with K) 161: |> filter [S -> and (S /= K) 162: ((String::index_of "/" (String::remove 0 (String::count K + 1) S)) < 0)] ] 163: 164: def db_page = [K -> 165: if db_has K then {h0 "The Egel Language", link "home" "", hr, db_get K |> db_action, hr 166: | db_subs K |> map [K -> link K K]} 167: else db_unknown] 168: 169: def db_action = [{} -> {} | {X|XX} -> map db_action {X|XX} |(action F) -> F none|X -> X] 170: 171: def db_pages = 172: { 173: ("", {line "Egel is an untyped concurrent functional scripting language based on eager", 174: line "combinator rewriting with a concise but remarkably powerful syntax.", 175: hr, 176: url "interpreter" "https://github.com/egel-lang/"}), 177: ("manual", action [_ -> code (OS::exec "MANWIDTH=80 man egel")]), 178: ("combinators", action [_ -> code (OS::exec "cat combinators.md")]), 179: ("self", action [_ -> code (OS::read_all (OS::open_in "serf.eg"))]) 180: } 181: 182: def db_unknown = {h0 "Uhoh", line "You seem to be lost!"} 183: )