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|
#!/usr/bin/env python3
import sys
import ply.yacc as yacc
from ply.lex import LexToken
# Get the token map from the lexer. This is required.
from lexer import tokens
import parsetypes as pt
# Error rule for syntax errors
def p_program(p):
"""program : instruction_list
| empty
"""
pass
def p_empty(p):
"""empty :"""
pass
def p_instructions(p):
"""instruction_list : instruction_list line
| line
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = p[1] + [p[2]]
pass
# try right-recursive?
def p_instructions2(p):
"""instruction_list2 : line instruction_list2
| line
"""
if len(p) == 2:
p[0] = [p[1]]
else:
p[0] = [p[1]] + p[2]
print(f"INSes2: {len(p)}")
print(f" {p[1]}")
if len(p) > 2:
print(f" {p[2]}")
pass
def p_line(p):
"""line : instruction NL
| NL
"""
if len(p) == 2:
pass
else:
p[0] = p[1]
def p_instruction(p):
"""instruction : no_args
| two_arg
| three_arg
| jumpdest
| one_arg_invalid
"""
print(f"Item: {p[1]}")
p[0] = p[1]
pass
def p_jumpdest(p):
"""jumpdest : symbol COLON"""
p[0] = (p[1],)
def p_no_arg(p):
"""no_args : opcode"""
p[0] = (*p[1], None, None, None)
pass
def p_onearg_invalid(p):
"""one_arg_invalid : opcode argument"""
print(f"Invalid number of arguments: {p[1:]}")
sys.exit(1)
pass
def p_two_arg(p):
"""two_arg : opcode register COMMA argument"""
p[0] = (*p[1], p[2], p[4], None)
pass
def p_three_arg(p):
"""three_arg : opcode register COMMA argument COMMA argument"""
p[0] = (*p[1], p[2], p[4], p[6])
pass
# checks which combinations are allowed is done one level up
def p_argument(p):
"""argument : number
| register
| symbol
"""
p[0] = p[1]
def p_symbol(p):
"""symbol : SYMBOL"""
p[0] = pt.Symbol(p[1])
def p_register(p):
"""register : REG"""
p[0] = pt.Register(p[1])
def p_opcode(p):
"""opcode : OP DOT JUMP
| OP
"""
if len(p) == 2:
p[0] = (p[1], None)
else:
p[0] = (p[1], p[3])
def p_number(p):
"""number : NUMBER
| HEXNUMBER
"""
p[0] = p[1]
def p_error(p: LexToken):
if p:
print(f"Unexpected {repr(p.value)} on line {p.lineno}")
else:
print("Unexpected end of file.")
parser = yacc.yacc()
|
