一，项目介绍
最终来到了编译器部分的最后一个章节——代码生成阶段。
本章的目标就是将Jack语言转化为VM语言，完毕Jack编译器的构建。
刚刚接触这章的内容时，会比較难上手。最基本的问题就在于，这章的内容看起来和第十章没有什么关系。刚開始做这个项目时，我就非常疑惑，第十章输出的不是一个结构化的xml文件吗？这个文件在第十一章根本不须要输出，那么这章的内容从何開始呢？
的确，这个xml文件是不须要输出的。可是第十章的目的并不单纯是输出这个xml文件，它更重要的目的是为了让我们了解怎样对jack程序文件进行语法分析，以完毕CompilationEngine的构建。所以，我们须要关注的是CompilationEngine的函数结构，这个函数结构才是第十一章内容的基础。
二，操作步骤
整体而言。作者为我们设计的操作顺序是很合理的。在此。我再提出几点预备步骤，这些步骤并非必要的。可是通过这些操作。可以使得整个项目的实现更加流畅。
1。先给命令行加上-x选项，假设命令行中出现-x，则表示输出xml文件和VM文件。不加-x。则表示仅仅输出VM文件。这样子就将两个不同“写入文件流”区分开来。
2。构建符号表模块。存储符号表时，我所用的数据结构是Python语言中的二维列表。
这一阶段的任务是把每个遇到的Identifier都加以标注而且输出相关信息。
3。进入输出VM语言的阶段。首先可以使用内置的JackCompiler将Jack语言转换为VM语言，（Windows上的JackCompiler须要自己设置配置文件才可以使用。详细教程在这儿）从简单的文件開始转换，自己认真分析代码的转换过程。比如，最简单的Seven函数的Jack代码和VM代码分别例如以下。
class Main {
function void main() {
do Output.printInt(1 + (2 * 3));
return;
}
}function Main.main 0 push constant 1 push constant 2 push constant 3 call Math.multiply 2 add call Output.printInt 1 pop temp 0 push constant 0 return
之后你便能够对比二者。分析转换规则了，比如第一句function Main.main 0肯定是在读取完了全部的ClassVarDev，知道了函数名之后才写入的，于是，写入语句必定就是在compileStatements之前。
照这个步骤。逐步完好你的编译器。
三，注意点
我的建议是。先回过头去复习VM代码和Jack语言，了解高级代码转化为VM代码的详细过程，你能够通过看图11.6，图7.9来了解当中的逻辑。
在写编译器的过程中。注意点许多。这一方面，书中11.2节阐述的很清楚，在此我重申几个比較关键的问题：
1，constructor, method和function參数配置不同，method方法会默认带一个this的參数。须要加以区分。而讨论參数时，VM代码中function xxx n与call function m中的n与m也是不同的。前者指的是函数中的局部变量数(local)。后者指的是调用函数时引入的參数(argument)。
2，Function和Method的调用方式不同，Function仅仅需调用类名ClassName.Function就能够使用，可是method须要调用详细的类实比如abc.Method才干够调用。假设方法就在类中的话，也可直接使用method()。
3，数组仅仅可能在两个地方出现，一是term中。用于引用，另外是Let语句的左边，用于数组赋值。要注意的是，这两处调用的VM代码是不同的。须要加以区分。
4，constructor是构造函数。在编译时，须要先分析Class中有多少个field变量，然后使用Memory.alloc(size)来给他们分配空间。最后再将其基地址存入this指针中。
上述这些注意点的详细代码都能够通过JackCompiler编译现有文件而得到。我就不再赘述了。
最后。debug的过程是痛苦的。也是无可避免的。假设代码出现故障，可以比对JackCompiler的输出文件与你的编译器输出文件的不同。
这个过程可以是你对编译有更深的理解。
JackCompiler.py
#!/usr/bin/python
import CompilationEngine
import SymbolTable
import sys,os
'''
The command line of this module is : JackCompiler.py (-x) sourcename
The first option is -x, which decides whether to run xmlWriter() and to output the constructive xml file
putting forward by CompilationEngine.
'''
option=sys.argv[1]
if option == '-x':
filename=sys.argv[2]
else:
filename=sys.argv[1]
#clear all the // /* ... notes, create a new file to save the result
readfile = open(filename,'r')
copyfile = open('copyfile','w')
line=readfile.readline()
while line:
while line == '
' or line.startswith('//'):
line=readfile.readline()
if '//' in line:
line=line[:line.find('//')]
if '/*' in line:
aline=line[:line.find('/*')]
while line.find('*/')<0:
line=readfile.readline()
bline=line[line.find('*/')+2:]
line=aline+bline
copyfile.write(line)
line=readfile.readline()
copyfile.close()
readfile.close()
#Main Function
readCopyFile=open('copyfile','r')
writeXmlFile=open(filename.strip('.jack')+'.xml','w')
writeVmFile=open(filename.strip('.jack')+'.vm','w')
outputCompile=CompilationEngine.Compile(readCopyFile,writeXmlFile,writeVmFile)
outputCompile.compileClass()
readCopyFile.close()
writeXmlFile.close()
writeVmFile.close()
os.remove('copyfile')
if option != '-x':
os.remove(filename.strip('.jack')+'.xml')
CompilationEngine.py
#!/usr/bin/python
import JackTokenizer
import SymbolTable
import VMWriter
class Compile():
def __init__(self,rfile,wfile,wVmFile):
self.rfile=rfile
self.wfile=wfile #Write XML file
self.vmWriter=VMWriter.VMwriter(wVmFile) #Write VM file
self.tokenizer=JackTokenizer.Tokenizer(self.rfile)
self.class_symbol=SymbolTable.SymbolTable()
self.sub_symbol=SymbolTable.SymbolTable()
self.Stype='' #Stype records the type of the identifier.
self.Skind=''
#ClassName records the name of the class, used to make the sub_functionName
self.ClassName=''
self.expressionListNum=0 #Record the number of expression in ExpressionList.
self.WHILEFLAG=0 #the index of while_loop in case of tautonomy
self.IFFLAG=0
def writeXmlTag(self,token):
self.wfile.write(token)
def writeXml(self,tType,token):
if tType == 'symbol':
if self.tokenizer.token=='>':
self.writeXmlTag('<'+tType+'> '+'>'+' </'+tType+'>
')
elif self.tokenizer.token=='<':
self.writeXmlTag('<'+tType+'> '+'<'+' </'+tType+'>
')
elif self.tokenizer.token=='&':
self.writeXmlTag('<'+tType+'> '+'&'+' </'+tType+'>
')
else:
self.writeXmlTag('<'+tType+'> '+token+' </'+tType+'>
')
else:
self.writeXmlTag('<'+tType+'> '+token+' </'+tType+'>
')
def NextToken(self):
if self.tokenizer.hasMoreTokens():
self.tokenizer.advance()
def moveBack(self):
#Move back to the last token.
lennum=-len(self.tokenizer.token)
self.rfile.seek(lennum,1)
def writeArrayPush(self,symbolName):
#This function is used in 'Push' Array Terms.
SubTag=self.sub_symbol.FoundName(symbolName)
if SubTag==-1:
ClassTag=self.class_symbol.FoundName(symbolName)
if ClassTag==-1:
print 'Error Term!'
exit()
else:
self.vmWriter.writePush('this',self.class_symbol.Scope[ClassTag][3])
else:
KINDFLAG=self.sub_symbol.Scope[SubTag][2]
self.vmWriter.writePush(KINDFLAG,self.sub_symbol.Scope[SubTag][3])
def defineSymbol(self,symbolName,_symbol):
#This function adds symbolName into SymbolTable.
_symbol.Define(symbolName,self.Stype,self.Skind)
def checkSymbol(self,symbolName):
#Check the index of the Identifier
SubTag=self.sub_symbol.FoundName(symbolName)
if SubTag==-1:
ClassTag=self.class_symbol.FoundName(symbolName)
if ClassTag==-1:
return -1
else:
return self.class_symbol.Scope[ClassTag]
else:
return self.sub_symbol.Scope[SubTag]
def compileType(self):
tType=self.tokenizer.tokenType()
if tType == 'KEYWORD':
self.Stype=self.tokenizer.token
self.writeXml('keyword',self.tokenizer.token)
elif tType == 'IDENTIFIER':
self.Stype=self.tokenizer.token
self.writeXml('identifier',self.tokenizer.token)
def compileTermType(self):
tType=self.tokenizer.tokenType()
if tType == 'KEYWORD':
kWord=self.tokenizer.token
if kWord=='true':
self.vmWriter.writePush('constant',1)
self.vmWriter.writeArithmetic('neg')
elif kWord=='false' or kWord=='null':
self.vmWriter.writePush('constant',0)
elif kWord=='this':
self.vmWriter.writePush('pointer',0)
self.writeXml('keyword',self.tokenizer.token)
elif tType == 'INT_CONSTANT':
self.writeXml('integerConstant',self.tokenizer.token)
self.vmWriter.writePush('constant',int(self.tokenizer.token))
elif tType == 'STRING_CONSTANT':
string_copy=self.tokenizer.token.strip('"')
self.writeXml('stringConstant',string_copy)
string_length=len(string_copy)
self.vmWriter.writePush('constant',string_length)
self.vmWriter.writeCall('String.new',1)
for i in range(0,string_length):
self.vmWriter.writePush('constant',ord(string_copy[i]))
self.vmWriter.writeCall('String.appendChar',2)
def compileVarDec(self):
'''
var type varName(,'varName')*;
'''
self.writeXmlTag('<varDec>
')
self.writeXml('keyword','var')
self.Skind='var'
#type
self.NextToken()
self.compileType()
#varName
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.defineSymbol(self.tokenizer.token,self.sub_symbol)
#(,varName)*
self.NextToken()
while self.tokenizer.token != ';':
self.writeXml('symbol',self.tokenizer.token)
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.defineSymbol(self.tokenizer.token,self.sub_symbol)
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.writeXmlTag('</varDec>
')
def compileParameterList(self):
'''
((type varName)(, type varName)*)?
'''
self.writeXmlTag('<parameterList>
')
self.NextToken()
while self.tokenizer.token != ')':
self.Skind='argument'
if self.tokenizer.token != ',':
self.compileType()
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.defineSymbol(self.tokenizer.token,self.sub_symbol)
self.NextToken()
else:
self.writeXml('symbol',self.tokenizer.token)
self.NextToken()
self.compileType()
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.defineSymbol(self.tokenizer.token,self.sub_symbol)
self.NextToken()
self.writeXmlTag('</parameterList>
')
def compileClassVarDec(self):
'''
('static'|'field') type varName(, varName)*;
'''
self.writeXmlTag('<classVarDec>
')
self.writeXml('keyword',self.tokenizer.token)
self.Skind=self.tokenizer.token
self.NextToken()
self.compileType()
#varName
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.defineSymbol(self.tokenizer.token,self.class_symbol)
#(,varName)*
self.NextToken()
while self.tokenizer.token != ';':
self.writeXml('symbol',self.tokenizer.token)
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.defineSymbol(self.tokenizer.token,self.class_symbol)
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.writeXmlTag('</classVarDec>
')
def compileTerm(self):
self.writeXmlTag('<term>
')
self.NextToken()
tType=self.tokenizer.tokenType()
if tType == 'IDENTIFIER':
temp=self.rfile.read(1)
if temp=='.':
lennum=-len(self.tokenizer.token)-1
self.rfile.seek(lennum,1)
self.subroutineCall()
elif temp=='[':
self.writeXml('identifier',self.tokenizer.token)
self.writeArrayPush(self.tokenizer.token)
self.writeXml('symbol','[')
self.compileExpression()
self.vmWriter.writeArithmetic('add')
self.vmWriter.writePop('pointer',1)
self.vmWriter.writePush('that',0)
self.writeXml('symbol',']')
else:
self.rfile.seek(-1,1)
self.writeXml('identifier',self.tokenizer.token)
ListSeg=self.checkSymbol(self.tokenizer.token)
self.vmWriter.writePush(ListSeg[2],ListSeg[3])
elif self.tokenizer.token in ('-','~'):
UnaryOp=self.tokenizer.token
self.writeXml('symbol',self.tokenizer.token)
self.compileTerm()
if UnaryOp == '-':
self.vmWriter.writeArithmetic('neg')
else:
self.vmWriter.writeArithmetic('not')
elif self.tokenizer.token == '(':
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.writeXml('symbol',')')
else:
self.compileTermType()
self.writeXmlTag('</term>
')
def compileExpression(self):
'''
term (op term)*
'''
self.writeXmlTag('<expression>
')
self.compileTerm()
self.NextToken()
while (self.tokenizer.tokenType() == 'SYMBOL' and
self.tokenizer.Symbol() in '+-*/&|<>='):
operator = self.tokenizer.Symbol()
self.writeXml('symbol', self.tokenizer.token)
self.compileTerm()
if operator == '+':
self.vmWriter.writeArithmetic('add')
elif operator == '-':
self.vmWriter.writeArithmetic('sub')
elif operator == '*':
self.vmWriter.writeCall('Math.multiply', 2)
elif operator == '/':
self.vmWriter.writeCall('Math.divide', 2)
elif operator == '&':
self.vmWriter.writeArithmetic('and')
elif operator == '|':
self.vmWriter.writeArithmetic('or')
elif operator == '<':
self.vmWriter.writeArithmetic('lt')
elif operator == '>':
self.vmWriter.writeArithmetic('gt')
elif operator == '=':
self.vmWriter.writeArithmetic('eq')
self.NextToken()
self.writeXmlTag('</expression>
')
def compileExpressionList(self):
self.writeXmlTag('<expressionList>
')
self.expressionListNum=0
self.NextToken()
while self.tokenizer.token != ')':
if self.tokenizer.token != ',':
self.moveBack()
self.compileExpression()
self.expressionListNum+=1
else:
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.expressionListNum+=1
self.writeXmlTag('</expressionList>
')
def subroutineCall(self):
sub_MethodFlag=False
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
sub_className=self.tokenizer.token
self.NextToken()
if self.tokenizer.token=='.':
self.writeXml('symbol',self.tokenizer.token)
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
sub_funcName=self.tokenizer.token
#To check if sub_className is a ClassName or an instance
SubCallTag=self.sub_symbol.FoundName(sub_className)
if SubCallTag==-1:
ClassCallTag=self.class_symbol.FoundName(sub_className)
if ClassCallTag==-1:
sub_Name=sub_className+'.'+sub_funcName
else:
sub_MethodFlag=True
sub_className=self.class_symbol.Scope[ClassCallTag][1]
sub_index=self.class_symbol.Scope[ClassCallTag][3]
self.vmWriter.writePush('this',sub_index)
sub_Name=sub_className+'.'+sub_funcName
else:
sub_MethodFlag=True
sub_className=self.sub_symbol.Scope[SubCallTag][1]
sub_index=self.sub_symbol.Scope[SubCallTag][3]
self.vmWriter.writePush('local',sub_index)
sub_Name=sub_className+'.'+sub_funcName
self.rfile.read(1)
self.writeXml('symbol','(')
self.compileExpressionList()
self.writeXml('symbol',')')
if sub_MethodFlag:
self.vmWriter.writeCall(sub_Name,self.expressionListNum+1)
else:
self.vmWriter.writeCall(sub_Name,self.expressionListNum)
elif self.tokenizer.token=='(':
sub_Name=self.ClassName+'.'+sub_className
self.writeXml('symbol','(')
self.vmWriter.writePush('pointer',0)
self.compileExpressionList()
self.vmWriter.writeCall(sub_Name,self.expressionListNum+1)
self.writeXml('symbol',')')
def compileDo(self):
self.writeXmlTag('<doStatement>
')
self.writeXml('keyword',self.tokenizer.token)
self.subroutineCall()
self.vmWriter.writePop('temp',0)
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.writeXmlTag('</doStatement>
')
def compileLet(self):
'''
If the term on the left of '=' is Array, the order of the VM code is
totally different from other conditions.
'''
self.writeXmlTag('<letStatement>
')
self.writeXml('keyword',self.tokenizer.token)
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
LetVarName=self.tokenizer.token
ListSeg=self.checkSymbol(LetVarName)
self.NextToken()
temp=self.tokenizer.token
if temp=='[':
self.writeArrayPush(LetVarName)
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.writeXml('symbol',']')
self.vmWriter.writeArithmetic('add')
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.vmWriter.writePop('temp',0)
self.vmWriter.writePop('pointer',1)
self.vmWriter.writePush('temp',0)
self.vmWriter.writePop('that',0)
self.writeXml('symbol',';')
self.writeXmlTag('</letStatement>
')
elif temp == '=':
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.vmWriter.writePop(ListSeg[2],ListSeg[3])
self.writeXml('symbol',';')
self.writeXmlTag('</letStatement>
')
def compileWhile(self):
self.writeXmlTag('<whileStatement>
')
self.writeXml('keyword',self.tokenizer.token)
sub_WHILEFLAG=self.WHILEFLAG
self.WHILEFLAG+=1
self.vmWriter.writeLabel('WHILE_START'+str(sub_WHILEFLAG))
#(expression)
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.writeXml('symbol',')')
self.vmWriter.writeArithmetic('not')
self.vmWriter.writeIf('WHILE_OVER'+str(sub_WHILEFLAG))
#{statements}
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileStatements()
self.vmWriter.writeGoto('WHILE_START'+str(sub_WHILEFLAG))
self.vmWriter.writeLabel('WHILE_OVER'+str(sub_WHILEFLAG))
self.writeXml('symbol',self.tokenizer.token)
self.writeXmlTag('</whileStatement>
')
def compileReturn(self):
self.writeXmlTag('<returnStatement>
')
self.writeXml('keyword',self.tokenizer.token)
#expression?
self.NextToken()
if self.tokenizer.token == ';':
self.writeXml('symbol',self.tokenizer.token)
self.vmWriter.writePush('constant',0)
self.vmWriter.writeReturn()
else:
self.moveBack()
self.compileExpression()
self.vmWriter.writeReturn()
self.writeXml('symbol',';')
self.writeXmlTag('</returnStatement>
')
def compileStatements(self):
self.writeXmlTag('<statements>
')
self.NextToken()
while self.tokenizer.token != '}':
if self.tokenizer.token =='let':
self.compileLet()
elif self.tokenizer.token == 'if':
self.compileIf()
elif self.tokenizer.token == 'while':
self.compileWhile()
elif self.tokenizer.token == 'do':
self.compileDo()
elif self.tokenizer.token == 'return':
self.compileReturn()
else:
print 'Error!'+self.tokenizer.token
exit()
self.NextToken()
self.writeXmlTag('</statements>
')
def compileIf(self):
self.writeXmlTag('<ifStatement>
')
sub_IFFLAG=self.IFFLAG
self.IFFLAG+=1
self.writeXml('keyword',self.tokenizer.token)
#(expression)
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileExpression()
self.writeXml('symbol',')')
self.vmWriter.writeArithmetic('not')
self.vmWriter.writeIf('IF_RIGHT'+str(sub_IFFLAG))
#{statements}
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileStatements()
self.writeXml('symbol',self.tokenizer.token)
#(else {statements})?
self.NextToken()
if self.tokenizer.token=='else':
self.vmWriter.writeGoto('IF_WRONG'+str(sub_IFFLAG))
self.vmWriter.writeLabel('IF_RIGHT'+str(sub_IFFLAG))
self.writeXml('keyword',self.tokenizer.token)
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileStatements()
self.vmWriter.writeLabel('IF_WRONG'+str(sub_IFFLAG))
self.writeXml('symbol',self.tokenizer.token)
else:
self.vmWriter.writeLabel('IF_RIGHT'+str(sub_IFFLAG))
self.moveBack()
self.writeXmlTag('</ifStatement>
')
def compileClass(self):
self.writeXmlTag('<class>
')
self.NextToken()
self.writeXml('keyword',self.tokenizer.token)
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
self.ClassName=self.tokenizer.token
self.NextToken()
self.writeXml('keyword',self.tokenizer.token)
#classVarDec*
self.NextToken()
while self.tokenizer.token in ('static','field'):
self.compileClassVarDec()
self.NextToken()
#subroutineDec*
while self.tokenizer.token in ('constructor','function','method'):
self.compileSubroutine()
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.writeXmlTag('</class>
')
def compileSubroutine(self):
Subroutine_Flag=''
self.WHILEFLAG=0
self.IFFLAG=0
self.writeXmlTag('<subroutineDec>
')
self.writeXml('keyword',self.tokenizer.token)
self.sub_symbol.startSubroutine()
if self.tokenizer.token =='method':
self.sub_symbol.Define('this',self.ClassName,'argument')
Subroutine_Flag='METHOD'
elif self.tokenizer.token == 'constructor':
Subroutine_Flag='CONSTRUCTOR'
else:
Subroutine_Flag='FUNCTION'
#(void|type) subroutineName (parameterList)
self.NextToken()
self.compileType()
self.NextToken()
self.writeXml('identifier',self.tokenizer.token)
#special, to be xxx.yyy
FunctionName=self.ClassName+'.'+self.tokenizer.token
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.compileParameterList()
self.writeXml('symbol',self.tokenizer.token)
#subroutinBody
self.writeXmlTag('<subroutineBody>
')
#{varDec* statements}
self.NextToken()
self.writeXml('symbol',self.tokenizer.token)
self.NextToken()
while self.tokenizer.token == 'var':
self.compileVarDec()
self.NextToken()
self.moveBack()
LclNum=self.sub_symbol.VarCount('var')
self.vmWriter.writeFunction(FunctionName,LclNum)
if Subroutine_Flag == 'METHOD':
self.vmWriter.writePush('argument',0)
self.vmWriter.writePop('pointer',0)
elif Subroutine_Flag=='CONSTRUCTOR':
FieldNum=self.class_symbol.VarCount('field')
self.vmWriter.writePush('constant',FieldNum)
self.vmWriter.writeCall('Memory.alloc',1)
self.vmWriter.writePop('pointer',0)
self.compileStatements()
self.writeXml('symbol',self.tokenizer.token)
self.writeXmlTag('</subroutineBody>
')
self.writeXmlTag('</subroutineDec>
')
SymbolTable.py
#!/usr/bin/python class SymbolTable: ''' SymbolTable is a two-dimensional list. The first list contains all the names of the symbols. And Each name is also a single list, containing the [name,type,kind,index] of the symbol. ''' def __init__(self): self.Scope=[] def Constructor(self): self.Scope=[] def startSubroutine(self): self.Scope=[] def FoundName(self,name): #Search the funcName in SymbolTable for i in range(0,len(self.Scope)): if name == self.Scope[i][0]: return i return -1 def Define(self,name,segType,kind): #Add new elements into the List. index=self.VarCount(kind) if kind == 'field': kind='this' elif kind == 'var': kind='local' name=[name,segType,kind,index] self.Scope.append(name) def VarCount(self,kind): #count the number of existed elements with 'kind'. #It is used to count the index of the elements. if kind == 'field': kind='this' elif kind == 'var': kind='local' lengthKind=0 for i in range(0,len(self.Scope)): if self.Scope[i][2]==kind: lengthKind+=1 return lengthKind def KindOf(self,name): for i in range(0,len(self.Scope)): if name == self.Scope[i][0]: return self.Scope[i][2] return 'NONE' def TypeOf(self,name): for i in range(0,len(self.Scope)): if name == self.Scope[i][0]: return self.Scope[i][1] return 'NONE' def IndexOf(self,name): for i in range(0,len(self.Scope)): if name == self.Scope[i][0]: return self.Scope[i][3] return 'NONE'
VMWriter.py
#!/usr/bin/python
class VMwriter:
def __init__(self,wfile):
self.wfile=wfile
def writePush(self,segment,index):
self.wfile.write('push '+segment+' '+str(index)+'
')
def writePop(self,segment,index):
self.wfile.write('pop '+segment+' '+str(index)+'
')
def writeArithmetic(self,command):
self.wfile.write(command+'
')
def writeFunction(self,functionName,LclNum):
self.wfile.write('function '+functionName+' '+str(LclNum)+'
')
def writeReturn(self):
self.wfile.write('return
')
def writeCall(self,functionName,ELNum):
self.wfile.write('call '+functionName+' '+str(ELNum)+'
')
def writeLabel(self,label):
self.wfile.write('label '+label+'
')
def writeGoto(self,label):
self.wfile.write('goto '+label+'
')
def writeIf(self,label):
self.wfile.write('if-goto '+label+'
')
JackTokenizer.py
#!/usr/bin/python
STable=('{','}','(',')','[',']','.',',',';','+','-','*','/','&','|','<','>','=','~')
KWtable=('class','constructor','function','method','field','static','var','int','char','boolean',
'void','true','false','null','this','let','do','if','else','while','return')
class Tokenizer():
def __init__(self,rfile):
self.rfile=rfile
self.token=''
def hasMoreTokens(self):
temp=self.rfile.read(1)
while temp in '
' and temp != '':
temp=self.rfile.read(1)
if not temp:
return 0
else:
self.rfile.seek(-1,1)
return 1
def advance(self):
self.token=''
temp=self.rfile.read(1)
if temp.isalpha() or temp.isdigit() or temp == '_':
while temp.isalpha() or temp.isdigit() or temp == '_':
self.token+=temp
temp=self.rfile.read(1)
if temp in STable or temp =='"':
self.rfile.seek(-1,1)
elif temp == ' ' or temp == '
':
self.rfile.seek(-1,1)
elif temp in STable:
self.token=temp
elif temp =='"':
self.token += '"'
temp=self.rfile.read(1)
while temp != '"':
self.token+=temp
temp=self.rfile.read(1)
self.token+='"'
def tokenType(self):
if self.token in KWtable:
return 'KEYWORD'
elif self.token in STable:
return 'SYMBOL'
elif self.token.isdigit():
return 'INT_CONSTANT'
elif self.token.startswith('"'):
return 'STRING_CONSTANT'
else:
return 'IDENTIFIER'
def Keyword(self):
return self.token
def Symbol(self):
return self.token
def Identifier(self):
return self.token
def intVal(self):
return int(self.token)
def stringVal(self):
return self.token