diff options
Diffstat (limited to 'tools/erlparse.lua')
| -rw-r--r-- | tools/erlparse.lua | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/tools/erlparse.lua b/tools/erlparse.lua new file mode 100644 index 00000000..c4372243 --- /dev/null +++ b/tools/erlparse.lua @@ -0,0 +1,130 @@ +
+local file = nil;
+local last = nil;
+local function read(expected)
+ local ch;
+ if last then
+ ch = last; last = nil;
+ else ch = file:read(1); end
+ if expected and ch ~= expected then error("expected: "..expected.."; got: "..(ch or "nil")); end
+ return ch;
+end
+local function pushback(ch)
+ if last then error(); end
+ last = ch;
+end
+local function peek()
+ if not last then last = read(); end
+ return last;
+end
+
+local _A, _a, _Z, _z, _0, _9, __, _space = string.byte("AaZz09_ ", 1, 8);
+local function isAlpha(ch)
+ ch = string.byte(ch) or 0;
+ return (ch >= _A and ch <= _Z) or (ch >= _a and ch <= _z);
+end
+local function isNumeric(ch)
+ ch = string.byte(ch) or 0;
+ return (ch >= _0 and ch <= _9);
+end
+local function isVar(ch)
+ ch = string.byte(ch) or 0;
+ return (ch >= _A and ch <= _Z) or (ch >= _a and ch <= _z) or (ch >= _0 and ch <= _9) or ch == __;
+end
+local function isSpace(ch)
+ ch = string.byte(ch) or "x";
+ return ch <= _space;
+end
+
+local function readString()
+ read("\""); -- skip quote
+ local slash = nil;
+ local str = "";
+ while true do
+ local ch = read();
+ if ch == "\"" and not slash then break; end
+ str = str..ch;
+ end
+ str = str:gsub("\\.", {["\\b"]="\b", ["\\d"]="\d", ["\\e"]="\e", ["\\f"]="\f", ["\\n"]="\n", ["\\r"]="\r", ["\\s"]="\s", ["\\t"]="\t", ["\\v"]="\v", ["\\\""]="\"", ["\\'"]="'", ["\\\\"]="\\"});
+ return str;
+end
+local function readSpecialString()
+ read("<"); read("<"); -- read <<
+ local str = "";
+ if peek() == "\"" then
+ local str = readString();
+ elseif peek() ~= ">" then
+ error();
+ end
+ read(">"); read(">"); -- read >>
+ return str;
+end
+local function readVar()
+ local var = read();
+ while isVar(peek()) do
+ var = var..read();
+ end
+ return var;
+end
+local function readNumber()
+ local num = read();
+ while isNumeric(peek()) do
+ num = num..read();
+ end
+ return tonumber(num);
+end
+local readItem = nil;
+local function readTuple()
+ local t = {};
+ read(); -- read { or [
+ while true do
+ local item = readItem();
+ if not item then break; end
+ table.insert(t, item);
+ end
+ read(); -- read } or ]
+ return t;
+end
+readItem = function()
+ local ch = peek();
+ if ch == nil then return nil end
+ if ch == "{" or ch == "[" then
+ return readTuple();
+ elseif isAlpha(ch) then
+ return readVar();
+ elseif isNumeric(ch) then
+ return readNumber();
+ elseif ch == "\"" then
+ return readString();
+ elseif ch == "<" then
+ return readSpecialString();
+ elseif isSpace(ch) or ch == "," then
+ read();
+ return readItem();
+ else
+ --print("Unknown char: "..ch);
+ return nil;
+ end
+end
+local function readChunk()
+ local x = readItem();
+ if x then read("."); end
+ return x;
+end
+local function readFile(filename)
+ file = io.open(filename);
+ if not file then error("File not found: "..filename); os.exit(0); end
+ return function()
+ local x = readChunk();
+ if not x and peek() then error("Invalid char: "..peek()); end
+ return x;
+ end;
+end
+
+module "erlparse"
+
+function parseFile(file)
+ return readFile(file);
+end
+
+return _M;
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