potatOS/minify/FormatIdentity.lua

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2021-03-31 18:58:54 +00:00
require'strict'
require'ParseLua'
local util = require'Util'
local function debug_printf(...)
--[[
util.printf(...)
--]]
end
--
-- FormatIdentity.lua
--
-- Returns the exact source code that was used to create an AST, preserving all
-- comments and whitespace.
-- This can be used to get back a Lua source after renaming some variables in
-- an AST.
--
local function Format_Identity(ast)
local out = {
rope = {}, -- List of strings
line = 1,
char = 1,
appendStr = function(self, str)
table.insert(self.rope, str)
local lines = util.splitLines(str)
if #lines == 1 then
self.char = self.char + #str
else
self.line = self.line + #lines - 1
local lastLine = lines[#lines]
self.char = #lastLine
end
end,
appendToken = function(self, token)
self:appendWhite(token)
--[*[
--debug_printf("appendToken(%q)", token.Data)
local data = token.Data
local lines = util.splitLines(data)
while self.line + #lines < token.Line do
print("Inserting extra line")
self.str = self.str .. '\n'
self.line = self.line + 1
self.char = 1
end
--]]
self:appendStr(token.Data)
end,
appendTokens = function(self, tokens)
for _,token in ipairs(tokens) do
self:appendToken( token )
end
end,
appendWhite = function(self, token)
if token.LeadingWhite then
self:appendTokens( token.LeadingWhite )
--self.str = self.str .. ' '
end
end
}
local formatStatlist, formatExpr;
formatExpr = function(expr)
local tok_it = 1
local function appendNextToken(str)
local tok = expr.Tokens[tok_it];
if str and tok.Data ~= str then
error("Expected token '" .. str .. "'. Tokens: " .. util.PrintTable(expr.Tokens))
end
out:appendToken( tok )
tok_it = tok_it + 1
end
local function appendToken(token)
out:appendToken( token )
tok_it = tok_it + 1
end
local function appendWhite()
local tok = expr.Tokens[tok_it];
if not tok then error(util.PrintTable(expr)) end
out:appendWhite( tok )
tok_it = tok_it + 1
end
local function appendStr(str)
appendWhite()
out:appendStr(str)
end
local function peek()
if tok_it < #expr.Tokens then
return expr.Tokens[tok_it].Data
end
end
local function appendComma(mandatory, seperators)
if true then
seperators = seperators or { "," }
seperators = util.lookupify( seperators )
if not mandatory and not seperators[peek()] then
return
end
assert(seperators[peek()], "Missing comma or semicolon")
appendNextToken()
else
local p = peek()
if p == "," or p == ";" then
appendNextToken()
end
end
end
debug_printf("formatExpr(%s) at line %i", expr.AstType, expr.Tokens[1] and expr.Tokens[1].Line or -1)
if expr.AstType == 'VarExpr' then
if expr.Variable then
appendStr( expr.Variable.Name )
else
appendStr( expr.Name )
end
elseif expr.AstType == 'NumberExpr' then
appendToken( expr.Value )
elseif expr.AstType == 'StringExpr' then
appendToken( expr.Value )
elseif expr.AstType == 'BooleanExpr' then
appendNextToken( expr.Value and "true" or "false" )
elseif expr.AstType == 'NilExpr' then
appendNextToken( "nil" )
elseif expr.AstType == 'BinopExpr' then
formatExpr(expr.Lhs)
appendStr( expr.Op )
formatExpr(expr.Rhs)
elseif expr.AstType == 'UnopExpr' then
appendStr( expr.Op )
formatExpr(expr.Rhs)
elseif expr.AstType == 'DotsExpr' then
appendNextToken( "..." )
elseif expr.AstType == 'CallExpr' then
formatExpr(expr.Base)
appendNextToken( "(" )
for i,arg in ipairs( expr.Arguments ) do
formatExpr(arg)
appendComma( i ~= #expr.Arguments )
end
appendNextToken( ")" )
elseif expr.AstType == 'TableCallExpr' then
formatExpr( expr.Base )
formatExpr( expr.Arguments[1] )
elseif expr.AstType == 'StringCallExpr' then
formatExpr(expr.Base)
appendToken( expr.Arguments[1] )
elseif expr.AstType == 'IndexExpr' then
formatExpr(expr.Base)
appendNextToken( "[" )
formatExpr(expr.Index)
appendNextToken( "]" )
elseif expr.AstType == 'MemberExpr' then
formatExpr(expr.Base)
appendNextToken() -- . or :
appendToken(expr.Ident)
elseif expr.AstType == 'Function' then
-- anonymous function
appendNextToken( "function" )
appendNextToken( "(" )
if #expr.Arguments > 0 then
for i = 1, #expr.Arguments do
appendStr( expr.Arguments[i].Name )
if i ~= #expr.Arguments then
appendNextToken(",")
elseif expr.VarArg then
appendNextToken(",")
appendNextToken("...")
end
end
elseif expr.VarArg then
appendNextToken("...")
end
appendNextToken(")")
formatStatlist(expr.Body)
appendNextToken("end")
elseif expr.AstType == 'ConstructorExpr' then
appendNextToken( "{" )
for i = 1, #expr.EntryList do
local entry = expr.EntryList[i]
if entry.Type == 'Key' then
appendNextToken( "[" )
formatExpr(entry.Key)
appendNextToken( "]" )
appendNextToken( "=" )
formatExpr(entry.Value)
elseif entry.Type == 'Value' then
formatExpr(entry.Value)
elseif entry.Type == 'KeyString' then
appendStr(entry.Key)
appendNextToken( "=" )
formatExpr(entry.Value)
end
appendComma( i ~= #expr.EntryList, { ",", ";" } )
end
appendNextToken( "}" )
elseif expr.AstType == 'Parentheses' then
appendNextToken( "(" )
formatExpr(expr.Inner)
appendNextToken( ")" )
else
print("Unknown AST Type: ", statement.AstType)
end
assert(tok_it == #expr.Tokens + 1)
debug_printf("/formatExpr")
end
local formatStatement = function(statement)
local tok_it = 1
local function appendNextToken(str)
local tok = statement.Tokens[tok_it];
assert(tok, string.format("Not enough tokens for %q. First token at %i:%i",
str, statement.Tokens[1].Line, statement.Tokens[1].Char))
assert(tok.Data == str,
string.format('Expected token %q, got %q', str, tok.Data))
out:appendToken( tok )
tok_it = tok_it + 1
end
local function appendWhite()
local tok = statement.Tokens[tok_it];
out:appendWhite( tok )
tok_it = tok_it + 1
end
local function appendStr(str)
appendWhite()
out:appendStr(str)
end
local function appendComma(mandatory)
if mandatory
or (tok_it < #statement.Tokens and statement.Tokens[tok_it].Data == ",") then
appendNextToken( "," )
end
end
debug_printf("")
debug_printf(string.format("formatStatement(%s) at line %i", statement.AstType, statement.Tokens[1] and statement.Tokens[1].Line or -1))
if statement.AstType == 'AssignmentStatement' then
for i,v in ipairs(statement.Lhs) do
formatExpr(v)
appendComma( i ~= #statement.Lhs )
end
if #statement.Rhs > 0 then
appendNextToken( "=" )
for i,v in ipairs(statement.Rhs) do
formatExpr(v)
appendComma( i ~= #statement.Rhs )
end
end
elseif statement.AstType == 'CallStatement' then
formatExpr(statement.Expression)
elseif statement.AstType == 'LocalStatement' then
appendNextToken( "local" )
for i = 1, #statement.LocalList do
appendStr( statement.LocalList[i].Name )
appendComma( i ~= #statement.LocalList )
end
if #statement.InitList > 0 then
appendNextToken( "=" )
for i = 1, #statement.InitList do
formatExpr(statement.InitList[i])
appendComma( i ~= #statement.InitList )
end
end
elseif statement.AstType == 'IfStatement' then
appendNextToken( "if" )
formatExpr( statement.Clauses[1].Condition )
appendNextToken( "then" )
formatStatlist( statement.Clauses[1].Body )
for i = 2, #statement.Clauses do
local st = statement.Clauses[i]
if st.Condition then
appendNextToken( "elseif" )
formatExpr(st.Condition)
appendNextToken( "then" )
else
appendNextToken( "else" )
end
formatStatlist(st.Body)
end
appendNextToken( "end" )
elseif statement.AstType == 'WhileStatement' then
appendNextToken( "while" )
formatExpr(statement.Condition)
appendNextToken( "do" )
formatStatlist(statement.Body)
appendNextToken( "end" )
elseif statement.AstType == 'DoStatement' then
appendNextToken( "do" )
formatStatlist(statement.Body)
appendNextToken( "end" )
elseif statement.AstType == 'ReturnStatement' then
appendNextToken( "return" )
for i = 1, #statement.Arguments do
formatExpr(statement.Arguments[i])
appendComma( i ~= #statement.Arguments )
end
elseif statement.AstType == 'BreakStatement' then
appendNextToken( "break" )
elseif statement.AstType == 'RepeatStatement' then
appendNextToken( "repeat" )
formatStatlist(statement.Body)
appendNextToken( "until" )
formatExpr(statement.Condition)
elseif statement.AstType == 'Function' then
--print(util.PrintTable(statement))
if statement.IsLocal then
appendNextToken( "local" )
end
appendNextToken( "function" )
if statement.IsLocal then
appendStr(statement.Name.Name)
else
formatExpr(statement.Name)
end
appendNextToken( "(" )
if #statement.Arguments > 0 then
for i = 1, #statement.Arguments do
appendStr( statement.Arguments[i].Name )
appendComma( i ~= #statement.Arguments or statement.VarArg )
if i == #statement.Arguments and statement.VarArg then
appendNextToken( "..." )
end
end
elseif statement.VarArg then
appendNextToken( "..." )
end
appendNextToken( ")" )
formatStatlist(statement.Body)
appendNextToken( "end" )
elseif statement.AstType == 'GenericForStatement' then
appendNextToken( "for" )
for i = 1, #statement.VariableList do
appendStr( statement.VariableList[i].Name )
appendComma( i ~= #statement.VariableList )
end
appendNextToken( "in" )
for i = 1, #statement.Generators do
formatExpr(statement.Generators[i])
appendComma( i ~= #statement.Generators )
end
appendNextToken( "do" )
formatStatlist(statement.Body)
appendNextToken( "end" )
elseif statement.AstType == 'NumericForStatement' then
appendNextToken( "for" )
appendStr( statement.Variable.Name )
appendNextToken( "=" )
formatExpr(statement.Start)
appendNextToken( "," )
formatExpr(statement.End)
if statement.Step then
appendNextToken( "," )
formatExpr(statement.Step)
end
appendNextToken( "do" )
formatStatlist(statement.Body)
appendNextToken( "end" )
elseif statement.AstType == 'LabelStatement' then
appendNextToken( "::" )
appendStr( statement.Label )
appendNextToken( "::" )
elseif statement.AstType == 'GotoStatement' then
appendNextToken( "goto" )
appendStr( statement.Label )
elseif statement.AstType == 'Eof' then
appendWhite()
else
print("Unknown AST Type: ", statement.AstType)
end
if statement.Semicolon then
appendNextToken(";")
end
assert(tok_it == #statement.Tokens + 1)
debug_printf("/formatStatment")
end
formatStatlist = function(statList)
for _, stat in ipairs(statList.Body) do
formatStatement(stat)
end
end
formatStatlist(ast)
return true, table.concat(out.rope)
end
return Format_Identity