| 1 | local t = { op = {}, keyword = {}, name = {}, eos = {}, string = {}, regex = {} }; |
| 2 | |
| 3 | local debug = function (...) io.stderr:write(table.concat({...}, "\t")); io.stderr:write"\n";end; |
| 4 | local debug = function () end |
| 5 | |
| 6 | local function read_balanced(tokens, start, left, right) |
| 7 | local c = 0; |
| 8 | for i=start,#tokens do |
| 9 | if tokens[i].type == "op" then |
| 10 | local token = tokens[i].value; |
| 11 | if token == left then |
| 12 | c = c + 1; |
| 13 | elseif token == right then |
| 14 | c = c - 1; |
| 15 | end |
| 16 | end |
| 17 | if c == 0 then return i; end |
| 18 | end |
| 19 | return start; |
| 20 | end |
| 21 | |
| 22 | local pair_op = { ["("] = ")", ["{"] = "}", ["["] = "]" }; |
| 23 | local function read_balanced_to(tokens, start, to) |
| 24 | local c = 0; |
| 25 | local i = start; |
| 26 | while i <= #tokens do |
| 27 | if tokens[i].type == "op" or tokens[i].type == "eos" then |
| 28 | local token = tokens[i].value; |
| 29 | if token == to then return i; end |
| 30 | |
| 31 | if pair_op[token] then |
| 32 | i = read_balanced(tokens, i, token, pair_op[token]); |
| 33 | end |
| 34 | end |
| 35 | i = i + 1; |
| 36 | end |
| 37 | return nil; |
| 38 | end |
| 39 | |
| 40 | function js2lua(tokens, write) |
| 41 | |
| 42 | -- Scan |
| 43 | local i = 1; |
| 44 | while i <= #tokens do |
| 45 | local token = tokens[i]; |
| 46 | debug(token.type, token.value); |
| 47 | if token.type == "keyword" and token.value == "function" then |
| 48 | local j = read_balanced_to(tokens, i+3, ")"); -- Find matching ) |
| 49 | j = j + 1; -- j now points to { |
| 50 | local k = read_balanced_to(tokens, j+1, "}"); |
| 51 | table.remove(tokens, j); -- Remove { |
| 52 | tokens[k-1].type, tokens[k-1].value = "keyword", "end"; |
| 53 | elseif token.type == "keyword" and token.value == "if" then |
| 54 | table.remove(tokens, i+1); -- Remove ( |
| 55 | local j = read_balanced_to(tokens, i, ")"); |
| 56 | tokens[j].type, tokens[j].value = "keyword", "then"; |
| 57 | |
| 58 | -- Make sure to end a single-statement block |
| 59 | if tokens[j+1].type ~= "op" or tokens[j+1].value ~= "{" then |
| 60 | local eos = read_balanced_to(tokens, j+1, ";"); |
| 61 | if tokens[eos+1].type ~= "keyword" or tokens[eos+1].value ~= "else" then |
| 62 | table.insert(tokens, eos+1, { type = "keyword", value = "end" }); |
| 63 | end |
| 64 | end |
| 65 | elseif token.type == "keyword" and token.value == "else" then |
| 66 | if tokens[i+1].type == "keyword" and tokens[i+1].value == "if" then |
| 67 | token.value = "elseif"; |
| 68 | table.remove(tokens, i+1); |
| 69 | |
| 70 | table.remove(tokens, i+1); -- Remove ( |
| 71 | local j = read_balanced_to(tokens, i, ")"); |
| 72 | tokens[j].type, tokens[j].value = "keyword", "then"; |
| 73 | end |
| 74 | |
| 75 | -- Make sure to end a single-statement block |
| 76 | if tokens[i+1].type ~= "op" or tokens[i+1].value ~= "{" then |
| 77 | local eos = read_balanced_to(tokens, i+1, ";"); |
| 78 | if tokens[eos+1].type ~= "keyword" or tokens[eos+1].value ~= "else" then |
| 79 | table.insert(tokens, eos+1, { type = "keyword", value = "end" }); |
| 80 | end |
| 81 | end |
| 82 | elseif token.type == "op" and token.value == "+" and tokens[i-1].type == "string" then |
| 83 | token.value = ".."; |
| 84 | elseif token.type == "op" and token.value == "{" then |
| 85 | elseif token.type == "keyword" and token.value == "var" then |
| 86 | token.value = "local"; |
| 87 | end |
| 88 | i = i + 1; |
| 89 | end |
| 90 | |
| 91 | -- Serialize |
| 92 | local last_token_type; |
| 93 | for _, token in ipairs(tokens) do |
| 94 | if token.type == "string" then |
| 95 | write("\""); |
| 96 | elseif token.type == "name" then |
| 97 | if last_token_type == "keyword" or last_token_type == "name" or last_token_type == "number" then |
| 98 | write(" "); |
| 99 | end |
| 100 | elseif token.type == "keyword" then |
| 101 | if last_token_type == "keyword" or last_token_type == "name" or last_token_type == "number" then |
| 102 | write(" "); |
| 103 | end |
| 104 | end |
| 105 | write(token.value); |
| 106 | if token.type == "string" then |
| 107 | write("\""); |
| 108 | end |
| 109 | last_token_type = token.type; |
| 110 | end |
| 111 | end |
| 112 | |
| 113 | return js2lua; |