寻找用PHP实现的BASIC解释器

Question

有谁知道将解释BASIC代码的PHP程序？我看到LOLCODE implementation似乎是一个很好的起点，但是如果有人已经开发出类似的东西，我会很感激。

Answer 1

在PHP中找不到一个，但Javascript中有一个：http://stevehanov.ca/blog/index.php?id=92。如果你向下滚动那个页面，作者会花很多精力来解释这个东西是如何运作的，哪个IMO是一个好的起点。

Answer 2

这实际上就是几个月前我写的：

http://pub.32kb.org/files/entry/pBasic/pBasic.zip

这是JAVA中一个文件BASIC实现的端口，名为jASIC，可在此处找到：

http://journal.stuffwithstuff.com/2010/07/18/jasic-a-complete-interpreter-in-one-java-file

用法是这样的：

$pbas = new pBasic();
$basicScript = file_get_contents('test.bas');
// execute
$pbas->interpret($basicScript);

这是我用于游戏概念的BASIC脚本示例：

' list all the files on the current server, by memmaker

println ""                                      ' used to produce a blank line in the        output, the "" is needed for the parser

if "bin" = arg1 then getbinaries                ' determine which directory to show

print "Listing of / on " + _ENV_CONNECTED_SERVER
allfiles = list_files()                         ' get list of files from the system

goto init

getbinaries:

print "Listing of /bin on " + _ENV_CONNECTED_SERVER
allfiles = list_files(1)                        ' get list of bin files from the system

init:

filecount = count(allfiles)                     ' get the length of the array

counter = 0                                     ' init the counter for the loop

println " - " + filecount + " files found"      ' print the file count, note the "" prefix is needed because pBasic infers the type from the left argument of a binary operator

println ""

beginloop:

println get_element(allfiles, counter)          ' output the current filename

counter = counter + 1                           ' increment the loop counter

if counter < filecount then beginloop           ' break the loop when all files are output

正如您所看到的，我扩展了原始的jASIC解释器并添加了函数调用和其他一些小的更改。