pseudocode.txt

code
codeidx
table
tableidx
list
listidx
level
registercounter

parse
	set up global variables
	registercounter = -1
	emit JMP (7, 0, 0, M = 0)
	addtosymboltable(3, "main", 0, 0, 0, 0)
	level = -1
	block()
	check for error 1
	emit HLT (11, 0, 0, 0)
	code[0].m = table[0].addr
	for i = 0, i < codeidx, i++
		if code[i].opcode == 5
			code[i].m = table[code[i].m].addr
	print table and or code
	return code
block
	level++
	procedureidx = tableidx - 1
	x = var-declaration()
	procedure-declaration()
	table[procedureidx].addr = codeidx
	emit INC (6, 0, 0, M = x)
	statement()
	mark()
	level--
var-declaration
	memorysize = 3
	symbolname
	arraysize
	if list[listidx] is varsym
		do
			listidx++
			if list[listidx] is not identsym 
				error 2
			if multipledeclarationcheck(list[listidx].name) != -1
				error 3
			symbolname = list[listidx].name
			listidx++
			if list[listidx] is lbracketsym
				listidx++
				if list[listidx] is not numbersym || list[listidx].value == 0
					error 4
				arraysize = list[listidx].value
				listidx++
				if list[listidx] is multsym, divsym, modsym, addsym, subsym
					error 4
				else if list[listidx] is not rbracket
					error 5
				listidx++
				addtosymboltable(2, symbolname, arraysize, level, memorysize, 0)
				memorysize += arraysize
			else
				addtosymboltable(1, symbolname, 0, level, memorysize, 0)
				memorysize++
		while list[listidx] is commasym
		if list[listidx] is identsym
			error 6
		else if list[listidx] is not semicolonsym
			error 7
		listidx++
		return memorysize
	else
		return memorysize
procedure-declaration
	symbolname
	while list[listidx] is proceduresym
		listidx++
		if list[listidx] is not identsym
			error 2
		else if multipledeclarationcheck(list[listidx].name) != -1
			error 3
		symbolname = list[listidx].name
		listidx++
		if list[listidx] is not semicolonsym
			error 8
		listidx++
		addtosymboltable(3, symbolname, 0, level, 0, 0)
		block()
		if list[listidx] is not semicolonsym
			error 7
		listidx++
		emit RET (2, 0, 0, 0)
statement
	symbolname
	symidx
	arrayidxreg
	varlocreg
	jpcidx
	jmpidx
	loopidx
	assignment
		symbolname = list[listidx].name
		listidx++
		if list[listidx] is lbracketsym
			listidx++
			symidx = findsymbol(symbolname, 2)
			if symidx == -1
				if findsymbol(symbolname, 1) != -1
					error 11
				else if findsymbol(symbolname, 3) != -1
					error 9
				else
					error 10
			expression()
			arrayidxreg = registercounter
			if list[listidx] is not rbracketsym
				error 5
			listidx++
			if list[listidx] is not assignsym
				error 13
			listidx++
			expression()
			registercounter++
			if registercounter >= 10
				error 14
			emit LIT (1, R = registercounter, 0, M = table[symidx].addr)
			emit ADD (13, R = arrayidxreg, L = arrayidxreg, registercounter)
			registercounter--
			emit STO (4, R = registercounter, L = level - table[symidx].level, M = arrayidxreg)
			registercounter -= 2
		else
			symidx = findsymbol(symbolname, 1)
			if symidx == -1
				if findsymbol(symbolname, 2) != -1
					error 12
				else if findsymbol(symbolname, 3) != -1
					error 9
				else
					error 10
			registercounter++
			if registercounter >= 10
				error 14
			emit LIT(1, R = registercounter, 0, M = table[symidx].addr)
			varlocreg = registercounter
			if list[listidx] is not assignsym
				error 13
			listidx++
			expression()
			emit STO (4, R = registercounter, L = level - table[symidx].level, M = varlocreg)
			registercounter -= 2
	call
		listidx++
		if list[listidx] is not identsym
			error 15
		symidx = findsymbol(list[listidx].name, 3)
		if symidx == -1
			if findsymbol(list[listidx].name, 1) != -1 || findsymbol(list[listidx].name, 2) != -1
				error 15
			else
				error 10
		emit CAL (5, 0, L = level - table[symidx].level, M = symidx)
		listidx++
	begin-end
		do
			listidx++
			statement()
		while list[listidx] is semicolonsym
		if list[listidx] is not endsym
			if list[listidx] is identsym, callsym, beginsym, ifsym, dosym, readsym, or writesym
				error 16
			else
				error 17
		listidx++
	if
		listidx++
		condition()
		jpcidx = codeidx
		emit JPC (8, R = registercounter, 0, M = 0)
		registercounter--
		if list[listidx] is not questionsym
			error 18
		listidx++
		statement()
		if list[listidx] is colonsym
			listidx++
			jmpidx = codeidx
			emit JMP (7, 0, 0, M = 0)
			code[jpcidx].m = codeidx
			statement()
			code[jmpidx].m = codeidx
		else
			code[jpcidx].m = codeidx
	do-while
		listidx++
		loopidx = codeidx
		statement()
		if list[listidx] is not whilesym
			error 19
		listidx++
		condition()
		registercounter++
		if registercounter >= 10
			error 14
		emit LIT(1, R = registercounter, 0, M = 0)
		emit EQL (18, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
		emit JPC (8, R = registercounter, 0, M = loopidx)
		registercounter--
	read
		listidx++
		if list[listidx] is not identsym
			error 20
		symbolname = list[listidx].name
		listidx++
		if list[listidx] is lbracketsym
			listidx++
			symidx = findsymbol(symbolname, 2)
			if symidx == -1
				if findsymbol(symbolname, 1) != -1
					error 11
				else if findsymbol(symbolname, 3) != -1
					error 9
				else
					error 10
			expression()
			arrayidxreg = registercounter
			if list[listidx] is not rbracketsym
				error 5
			listidx++
			registercounter++
			if registercounter >= 10
				error 14
			emit RED (10, R = registercounter, 0, 0)
			registercounter++
			if registercounter >= 10
				error 14
			emit LIT (1, R = registercounter, 0, table[symidx].addr)
			emit ADD (13, R = arrayidxreg, L = arrayidxreg, M = registercounter)
			registercounter--
			emit STO (4, R = registercounter, L = level - table[symidx].level, M = arrayidxreg)
			registercounter -= 2
		else
			symidx = findsymbol(symbolname, 1)
			if symidx == -1
				if findsymbol(symbolname, 2) != -1
					error 12
				else if findsymbol(symbolname, 3) != -1
					error 9
				else
					error 10
			registercounter++
			if registercounter >= 10
				error 14
			emit LIT (1, R = registercounter, 0, table[symidx].addr)
			varlocreg = registercounter
			registercounter++
			if registercounter >= 10
				error 14
			emit RED (10, R = registercounter, 0, 0)
			emit STO (4, R = registercounter, L = level - table[symidx].level, M = varlocreg)
			registercounter -= 2
	write
		listidx++
		expression()
		emit WRT (9, R = registercounter, 0, 0)
		registercounter--
condition
	expression()
	if list[listidx] is eqlsym
		listidx++
		expression()
		emit EQL (18, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
	else if list[listidx] is neqsym
		listidx++
		expression()
		emit NEQ (19, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
	else if list[listidx] is lsssym
		listidx++
		expression()
		emit LSS (20, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
	else if list[listidx] is leqsym
		listidx++
		expression()
		emit LEQ (21, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
	else if list[listidx] is gtrsym
		listidx++
		expression()
		emit GTR (22, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
	else if list[listidx] is geqsym
		listidx++
		expression()
		emit GEQ (23, R = registercounter - 1, L = registercounter - 1, M = registercounter)
		registercounter--
	else
		error 21
expression
	if list[listidx] is subsym
		listidx++
		term()
		emit NEG (12, R = registercounter, 0, M = registercounter)
		while list[listidx] is addsym or subsym
			if list[listidx] is addsym
				listidx++
				term()
				emit ADD (13, R = registercounter - 1, L = registercounter - 1, M = registercounter)
				registercounter--
			else
				listidx++
				term()
				emit SUB (14, R = registercounter - 1, L = registercounter - 1, M = registercounter)
				registercounter--
	else
		term()
		while list[listidx] is addsym or subsym
			if list[listidx] is addsym
				listidx++
				term()
				emit ADD (13, R = registercounter - 1, L = registercounter - 1, M = registercounter)
				registercounter--
			else
				listidx++
				term()
				emit SUB (14, R = registercounter - 1, L = registercounter - 1, M = registercounter)
				registercounter--
	if list[listidx] is lparenthesissym, identsym, or numbersym
		error 22
term
	factor()
	while list[listidx] is multsym, divsym, or modsym
		if list[listidx] is multsym
			listidx++
			factor()
			emit MUL (15, R = registercounter - 1, L = registercounter - 1, M = registercounter)
			registercounter--
		else if list[listidx] is divsym
			listidx++
			factor()
			emit DIV (16, R = registercounter - 1, L = registercounter - 1, M = registercounter)
			registercounter--
		else
			listidx++
			factor()
			emit MOD (17, R = registercounter - 1, L = registercounter - 1, M = registercounter)
			registercounter--
factor
	symbolname
	symidx
	arrayidxreg
	varlocreg
	if list[listidx] is identsym
		symbolname = list[listidx].name
		listidx++
		if list[listidx] is lbracketsym
			listidx++
			symidx = findsymbol(symbolname, 2)
			if symidx == -1
				if findsymbol(symbolname, 1) != -1
					error 11
				else if findsymbol(symbolname, 3) != -1
					error 9
				else
					error 10
			expression()
			arrayidxreg = registercounter
			if list[listidx] is not rbracketsym
				error 5
			listidx++
			registercounter++
			if registercounter >= 10
				error 14
			emit LIT (1, R = registercounter, 0, M = table[symidx].addr)
			emit ADD (13, R = arrayidxreg, L = arrayidxreg, M = registercounter)
			registercounter--
			emit LOD (3, R = registercounter, L = level - table[symidx].level, M = arrayidxreg)
		else
			symidx = findsymbol(symbolname, 1)
			if symidx == -1
				if findsymbol(symbolname, 2) != -1
					error 12
				else if findsymbol(symbolname, 3) != -1
					error 9
				else
					error 10
			registercounter++
			if registercounter >= 10
				error 14
			emit LIT (1, R = registercounter, 0, M = table[symidx].addr)
			varlocreg = registercounter
			emit LOD (3, R = registercounter, L = level - table[symidx].level, M = varlocreg)
	else if list[listidx] is numbersym
		registercounter++
		if registercounter >= 10
			error 14
		emit LIT (1, R = registercounter, 0, M = list[listidx].value)
		listidx++
	else if list[listidx] is lparenthesissym
		listidx++
		expression()
		if list[listidx] is not rparenthesissym
			error 23
		listidx++
	else
		error 24