A More Efficient If (VM Code) Than Shimon's

Shimon (or one of his underlings - maybe Yaron)

expression
if-goto IF_TRUE0
goto IF_FALSE0
label IF_TRUE0
if-statements
goto IF_END0
label IF_FALSE0
else-statements
label IF_END0

when all you really need is :

expression
if-goto IF_TRUE0
else-statements
goto IF_END0
label IF_TRUE0
if-statements
label IF_END0

So, why would they choose to implement the less optimal thing?

VMEmulator Help - Can't Set Value of a RAM Word

If you have your Animation set to "No Animation", then you won't be able to. So, change that to "Program Flow", set your RAM, and then revert..

Jack FAQ

Are fields private? Accessible only to methods? Or, if you have an object, can you do

obj.field from anywhere?

Can't find a good FAQ on their web :(

Nand2Tetris Jack Constructor VM Mapping

When python pip Spoils the Party

Your old version of pip tells you :

You should consider upgrading via the 'python -m pip install --upgrade pip' command.

Then, when you try :

$ python -m pip install --upgrade pip

/usr/bin/python: No module named pip

Thank you Guido!

Fortunately, googling got me

$ pip install -U pip

threw out a tonne of errors about permissions (this is Cygwin), but seems to be working okay..

$ pip --version       makes me happy

Python CSV to Excel (xlsx) Thanks to pyexcel

import pyexcel
import glob
import sys
import re
import os

# $ python script.py arg1 [arg2]
# # arg2 optional, arg1 not. arg1 a path to dir or *.csv or specific.csv
# arg2 can be -merged or specfic.xlsx
# if multiple infiles are seen, then if no arg2, each file will result in unique .xlsx

if ( os.path.isdir( sys.argv[1] ) ) :
    infiles = glob.glob( sys.argv[1] + '/*.csv' )
elif ( re.search( '.csv' , sys.argv[1] ) ) :
    infiles = glob.glob( sys.argv[1] )
else :
    sys.exit()

if ( len( sys.argv) > 2 ) :
    if ( re.search( '-merged' , sys.argv[2] ) ) :
        pyexcel.merge_csv_to_a_book( infiles , 'merged.xlsx' )
    elif( re.search( '.xlsx' , sys.argv[2] ) ) :
        pyexcel.merge_csv_to_a_book( infiles ,  sys.argv[2] )
else :
    for file in infiles :
        pyexcel.merge_csv_to_a_book( [file] , file.replace( '.csv' , '.xlsx' ) )

A Handy Debugging Tip If You're Using Python

You want to run until a certain condition is satisfied - because, once you get to an advanced level and you're analyzing the 'class' rule, you're up against subtle fails..

python -m pdb SynAnal Square/SquareTokens.xml

> break 115 , rule == 'paramList'

> c

Now, you get straight to the action. Nice?

Check out some Python performance tips here : https://wiki.python.org/moin/PythonSpeed

Jack Grammar - Only Rules Support * and ? - Not Primitives

After coding, I had to use Excel to see this - rather than comb through my text. The power of visualization..

Part of it is doing a rule using a formula : (in the box, type)

=AND( ISNUMBER(B2), B2 > 1 )

class	1	1	1	3	3	1
class	keyword	identifier	symbol	rule	rule	symbol
classVarDec	1	1	1	3	1
classVarDec	keyword	rule	identifier	rule	symbol
addlVarDec	1	1
addlVarDec	symbol	identifier
type	1
type	keyword||identifier
subroutineDec	1	1	1	1	1	1	1
subroutineDec	keyword	keyword||rule	identifier	symbol	rule	symbol	rule
parameterList	2
parameterList	rule
params	1	3
params	rule	rule
param	1	1
param	rule	identifier
addlParam	1	1
addlParam	symbol	identifier
subroutineBody	1	3	1	1
subroutineBody	symbol	rule	rule	symbol
varDec	1	1	1	3	1
varDec	keyword	rule	identifier	rule	symbol
statements	3
statements	rule
statement	1
statement	rule
letStatement	1	1	2	1	1	1
letStatement	keyword	identifier	rule	symbol	rule	symbol
index	1	1	1
index	symbol	rule	symbol
ifStatement	1	1	1	1	1	1	1	2
ifStatement	keyword	symbol	rule	symbol	symbol	rule	symbol	rule
elseBlock	1	1	1	1
elseBlock	keyword	symbol	rule	symbol
whileStatement	1	expression	)	1	1	1
whileStatement	keyword	symbol	rule	symbol	symbol	rule	symbol
doStatement	1	1	1
doStatement	keyword	rule	symbol
returnStatement	1	2	1
returnStatement	keyword	rule	symbol
expression	1	3
expression	rule	rule
subExp	1	1
subExp	symbol	rule
term	1
term	rule
constant	1
constant	integerConstant||stringConstant
arrayElem	1	1	1	1
arrayElem	rule	symbol	rule	symbol
paranthExp	1	1
paranthExp	symbol	rule	symbol
unOpTerm	1	1
unOpTerm	symbol	rule
subroutineCall	1
subroutineCall	rule
simpleCall	1	1	1	1
simpleCall	identifier	symbol	rule	symbol
classMethCall	1	1	1	1	1	1
classMethCall	identifier	symbol	identifier	symbol	rule	symbol
expressionList	2
expressionList	rule
expressions	1	3
expressions	rule	rule
addlExpr	1	1
addlExpr	symbol	rule
keywordConstant	true|false|null|this
keywordConstant	keyword