summaryrefslogtreecommitdiff
path: root/nandgame/assembler/lexer.py
blob: aab2549a5981240101938a4759f2962cc47b4584 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69

import ply.lex as lex

# List of token names.   This is always required
tokens = (
   'OP',
   'JUMP',
   'COMMA',
   'COLON',
   'SYMBOL',
   'NUMBER',
   'HEXNUMBER',
   'DOT',
   'REG',
   'NL'
)

# Regular expression rules for simple tokens
t_COMMA   = r','
t_COLON   = r':'
t_DOT     = r'\.'

def t_OP(t):
    r"mov|and|dec|hlt|add|sub|inc"
    return t

def t_REG(t):
    r"\b(AD?M?|DM?|M|_)\b"
    return t

def t_JUMP(t):
    r"jmp|jlt|jgt|jle|jge|jeq|jne"
    return t

def t_NUMBER(t):
    r'\#\d+'
    t.value = int(t.value[1:])
    return t

def t_HEXNUMBER(t):
    r'\#0x[0-9a-fA-F]+'
    t.value = int(t.value[1:], 16)
    return t

def t_SYMBOL(t):
    r'[a-z][A-Za-z0-9_]+'
    return t

# Define a rule so we can track line numbers
def t_NL(t):
    r'\n+'
    t.lexer.lineno += len(t.value)
    return t

# A string containing ignored characters (spaces and tabs)
t_ignore  = ' \t'
#t_ignore_COMMENT = r';.*'

def t_COMMENT(t):
    r';.*'
    pass

# Error handling rule
def t_error(t):
    print("!!! Illegal character '%s'" % t.value[0])
    t.lexer.skip(1)

# Build the lexer
lexer = lex.lex()