lambdaV: Implement parser
At this point, I have no idea how well it actually works as I have only performed basic sanity checks on it. But it seems to work.master
BodgeMaster
parent
eab0d86d7a
commit
c8ad44e93e
|
|
@ -0,0 +1,358 @@
|
|||
#!/usr/bin/env python3
|
||||
|
||||
# Copyright 2022, Jan Danielzick (aka. BodgeMaster)
|
||||
#
|
||||
# This program is free software: you can redistribute it and/or modify it
|
||||
# under the terms of the GNU General Public License as published
|
||||
# by the Free Software Foundation, version 3.
|
||||
#
|
||||
# This program is distributed in the hope that it will be useful,
|
||||
# but WITHOUT ANY WARRANTY; without even the implied
|
||||
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
|
||||
# See the GNU General Public License for more details.
|
||||
#
|
||||
# You should have received a copy of the GNU General Public License
|
||||
# version 3 along with this program.
|
||||
# If not, see https://www.gnu.org/licenses/gpl-3.0.en.html
|
||||
|
||||
import re
|
||||
|
||||
debug_mode = True
|
||||
|
||||
cursor_up = 'Λ'
|
||||
cursor_down = 'V'
|
||||
cursor_left = '<'
|
||||
cursor_right = '>'
|
||||
|
||||
empty_field = [
|
||||
" ________________ ",
|
||||
"| |",
|
||||
"| |",
|
||||
"| |",
|
||||
"| |",
|
||||
"| |",
|
||||
"| |",
|
||||
"| |",
|
||||
"| |",
|
||||
" ¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯ "
|
||||
]
|
||||
|
||||
wall = '#'
|
||||
apple = 'ó'
|
||||
goal = '$'
|
||||
|
||||
cursor_position = [0, 0]
|
||||
|
||||
|
||||
def debug_message(text):
|
||||
if debug_mode:
|
||||
print("DEBUG: ", end="")
|
||||
print(text)
|
||||
|
||||
def condition_in_front_of_wall(inverted):
|
||||
return False
|
||||
|
||||
def condition_goal_reached(inverted):
|
||||
return False
|
||||
|
||||
def condition_on_apple(inverted):
|
||||
return False
|
||||
|
||||
def condition_facing_north(inverted):
|
||||
return False
|
||||
|
||||
def condition_facing_south(inverted):
|
||||
return False
|
||||
|
||||
def condition_facing_east(inverted):
|
||||
return False
|
||||
|
||||
def condition_facing_west(inverted):
|
||||
return False
|
||||
|
||||
# condition prefixed with !
|
||||
def modifier_not(condition):
|
||||
return condition(true)
|
||||
|
||||
# return value: "" or error message
|
||||
def command_step():
|
||||
#TODO
|
||||
return ""
|
||||
|
||||
def command_left():
|
||||
return ""
|
||||
|
||||
def command_right():
|
||||
return ""
|
||||
|
||||
def command_repeat(number, parsed_code):
|
||||
return ""
|
||||
|
||||
def command_while(parsed_condition, parsed_code):
|
||||
return ""
|
||||
|
||||
def command_take():
|
||||
return ""
|
||||
|
||||
def command_if(parsed_condition, parsed_then_code, parsed_else_code):
|
||||
return ""
|
||||
|
||||
|
||||
# returns -1 for generic error
|
||||
# returns -2 if end can’t be found
|
||||
def get_length_of_condition(code):
|
||||
if len(code)==0:
|
||||
return -1
|
||||
if code[0] == '<':
|
||||
length = 0
|
||||
while length<len(code) and code[length]!='>':
|
||||
length = length+1
|
||||
if length==len(code) and code[-1]!='>':
|
||||
return -2
|
||||
return length+1
|
||||
else:
|
||||
return -1
|
||||
|
||||
|
||||
# returns -1 for generic error
|
||||
# returns -2 if end can’t be found
|
||||
def get_length_of_contained_code(code):
|
||||
if len(code)==0:
|
||||
return -1
|
||||
if code[0] == '(':
|
||||
length = 1
|
||||
nesting_level = 1
|
||||
while length<len(code) and nesting_level>0:
|
||||
if code[length] == '(':
|
||||
nesting_level = nesting_level+1
|
||||
elif code[length] == ')':
|
||||
nesting_level = nesting_level-1
|
||||
length = length+1
|
||||
if length==len(code) and nesting_level > 0:
|
||||
return -2
|
||||
return length
|
||||
else:
|
||||
return -1
|
||||
|
||||
# clean up whitespace
|
||||
def format_code(code):
|
||||
regex_pattern = re.compile(r'\s+')
|
||||
code = " ".join(re.sub(regex_pattern, ' ', code).lower().split())
|
||||
code = code.replace(" (", "(")
|
||||
code = code.replace("( ", "(")
|
||||
code = code.replace(" )", ")")
|
||||
code = code.replace(") ", ")")
|
||||
code = code.replace(" <", "<")
|
||||
code = code.replace("< ", "<")
|
||||
code = code.replace(" >", ">")
|
||||
code = code.replace("< ", "<")
|
||||
code = code.replace("! ", "!")
|
||||
# add spaces back after closing parenthesis
|
||||
code = code.replace(")", ") ")
|
||||
code = code.replace(") )", "))")
|
||||
code = code.replace(") )", "))")
|
||||
if len(code)>0 and code[-1]==' ':
|
||||
return code[:-1]
|
||||
return code
|
||||
|
||||
# returns [function, inverted?, error message]
|
||||
def parse_condition(condition_code, allowed_conditions):
|
||||
inverted = False
|
||||
condition = None
|
||||
if len(condition_code)==0:
|
||||
debug_message(" No condition specified")
|
||||
return [condition, inverted, "Syntax error: No condition specified"]
|
||||
if condition_code[0]=='!':
|
||||
debug_message(" Condition is inverted")
|
||||
inverted = True
|
||||
condition_code = condition_code[1:]
|
||||
if len(condition_code)==0:
|
||||
debug_message(" No condition specified")
|
||||
return [condition, inverted, "Syntax error: No condition specified"]
|
||||
|
||||
if condition_code == "in front of wall":
|
||||
condition = condition_in_front_of_wall
|
||||
elif condition_code == "goal reached":
|
||||
condition = condition_goal_reached
|
||||
elif condition_code == "on apple":
|
||||
condition = condition_on_apple
|
||||
elif condition_code == "facing north":
|
||||
condition = condition_facing_north
|
||||
elif condition_code == "facing south":
|
||||
condition = condition_facing_south
|
||||
elif condition_code == "facing east":
|
||||
condition = condition_facing_east
|
||||
elif condition_code == "facing west":
|
||||
condition = condition_facing_west
|
||||
else:
|
||||
debug_message(" Unknown condition: "+condition_code)
|
||||
return [condition, inverted, "Unknown condition: "+condition_code]
|
||||
return [condition, inverted, ""]
|
||||
|
||||
# returns [[functions], [arguments], -1, ""] or [[], [], error_position, "error message"]
|
||||
def parse_code(code, allowed_commands, allowed_conditions, unformatted_code=True):
|
||||
if unformatted_code:
|
||||
code = format_code(code)
|
||||
debug_message("Formatted code: "+code)
|
||||
|
||||
parse_position = 0
|
||||
parsed_code = [[], [], -1, ""]
|
||||
while parse_position < len(code):
|
||||
# find next command
|
||||
next_space = code.find(' ', parse_position)
|
||||
next_condition = code.find('<', parse_position)
|
||||
if next_space == -1:
|
||||
next_space = len(code)
|
||||
if next_condition == -1:
|
||||
next_condition = len(code)
|
||||
# Are we working with a simple command?
|
||||
if next_condition>next_space or next_condition==next_space:
|
||||
next_command = code[parse_position:next_space]
|
||||
debug_message("Next command is: "+next_command)
|
||||
|
||||
parsed_code[1].append(())
|
||||
#TODO: add function to to the function list
|
||||
if next_command == "step":
|
||||
parsed_code[0].append(command_step)
|
||||
elif next_command == "left":
|
||||
parsed_code[0].append(command_left)
|
||||
elif next_command == "right":
|
||||
parsed_code[0].append(command_right)
|
||||
elif next_command == "take":
|
||||
parsed_code[0].append(command_take)
|
||||
elif next_command == "repeat":
|
||||
return [[], [], next_space, "Syntax error: Condition missing"]
|
||||
elif next_command == "while":
|
||||
return [[], [], next_space, "Syntax error: Condition missing"]
|
||||
elif next_command == "if":
|
||||
return [[], [], next_space, "Syntax error: Condition missing"]
|
||||
elif next_command == "else":
|
||||
return [[], [], parse_position, "Syntax error: Else without if statement"]
|
||||
else:
|
||||
#TODO: better error message (especially when special chars are detected inside next_command or a known command)
|
||||
return [[], [], parse_position, "Unknown command: "+next_command]
|
||||
parse_position = next_space+1
|
||||
else:
|
||||
debug_message("Found control structure...")
|
||||
control_structure = code[parse_position:next_condition]
|
||||
if control_structure == "repeat":
|
||||
debug_message(" Type: repeat loop")
|
||||
parse_position = next_condition
|
||||
repetitions_length = get_length_of_condition(code[parse_position:])
|
||||
if repetitions_length == -2:
|
||||
debug_message(" Mismatched <>")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching '>' for this '<'"]
|
||||
repetitions = code[parse_position:parse_position+repetitions_length]
|
||||
debug_message(" Number of repetitions: "+repetitions)
|
||||
repetitions_int = 0
|
||||
try:
|
||||
repetitions_int = int(repetitions[1:-1])
|
||||
except ValueError:
|
||||
return [[], [], parse_position, "Not a valid number: "+repetitions[1:-1]]
|
||||
parse_position = parse_position+len(repetitions)
|
||||
contained_code_length = get_length_of_contained_code(code[parse_position:])
|
||||
if contained_code_length == -1:
|
||||
debug_message(" Missing (")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find '(' for contained code"]
|
||||
if contained_code_length == -2:
|
||||
debug_message(" Mismatched ()")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching ')' for this '('"]
|
||||
contained_code = code[parse_position:parse_position+contained_code_length]
|
||||
debug_message(" Contained code: "+contained_code)
|
||||
parsed_contained_code = parse_code(contained_code[1:-1], allowed_commands, allowed_conditions, unformatted_code=False)
|
||||
if not parsed_contained_code[2]==-1:
|
||||
debug_message(" Error while parsing contained code")
|
||||
return [[], [], parse_position+1+parsed_contained_code[2], parsed_contained_code[3]]
|
||||
parse_position = parse_position+contained_code_length+1
|
||||
|
||||
parsed_code[1].append((repetitions_int, parsed_contained_code))
|
||||
parsed_code[0].append(command_repeat)
|
||||
continue
|
||||
elif control_structure == "if":
|
||||
debug_message(" Type: if statement")
|
||||
parse_position = next_condition
|
||||
condition_length = get_length_of_condition(code[parse_position:])
|
||||
if condition_length == -2:
|
||||
debug_message(" Mismatched <>")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching '>' for this '<'"]
|
||||
condition = code[parse_position:parse_position+condition_length]
|
||||
debug_message(" Condition is: "+condition)
|
||||
parsed_condition = parse_condition(condition[1:-1], allowed_conditions)
|
||||
if not parsed_condition[2]=="":
|
||||
return [[], [], parse_position, parsed_condition[2]]
|
||||
parse_position = parse_position+len(condition)
|
||||
then_code_length = get_length_of_contained_code(code[parse_position:])
|
||||
if then_code_length == -1:
|
||||
debug_message(" Missing (")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find '(' for then-code"]
|
||||
if then_code_length == -2:
|
||||
debug_message(" Mismatched ()")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching ')' for this '('"]
|
||||
then_code = code[parse_position:parse_position+then_code_length]
|
||||
debug_message(" Then-code: "+then_code)
|
||||
parsed_then_code = parse_code(then_code[1:-1], allowed_commands, allowed_conditions, unformatted_code=False)
|
||||
if not parsed_then_code[2]==-1:
|
||||
debug_message(" Error while parsing then-code")
|
||||
return [[], [], parse_position+1+parsed_then_code[2], parsed_then_code[3]]
|
||||
parse_position = parse_position+then_code_length+1
|
||||
parsed_else_code = None
|
||||
if parse_position<len(code)+4 and code[parse_position:parse_position+4]=="else":
|
||||
parse_position = parse_position+4
|
||||
else_code_length = get_length_of_contained_code(code[parse_position:])
|
||||
if else_code_length == -1:
|
||||
debug_message(" Missing (")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find '(' for else-code"]
|
||||
if else_code_length == -2:
|
||||
debug_message(" Mismatched ()")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching ')' for this '('"]
|
||||
else_code = code[parse_position:parse_position+else_code_length]
|
||||
debug_message(" Else-code: "+else_code)
|
||||
parsed_else_code = parse_code(else_code[1:-1], allowed_commands, allowed_conditions, unformatted_code=False)
|
||||
parse_position = parse_position+else_code_length+1
|
||||
|
||||
parsed_code[1].append((parsed_condition, parsed_then_code, parsed_else_code))
|
||||
parsed_code[0].append(command_if)
|
||||
continue
|
||||
elif control_structure == "while":
|
||||
debug_message(" Type: while loop")
|
||||
parse_position = next_condition
|
||||
condition_length = get_length_of_condition(code[parse_position:])
|
||||
if condition_length == -2:
|
||||
debug_message(" Mismatched <>")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching '>' for this '<'"]
|
||||
condition = code[parse_position:parse_position+condition_length]
|
||||
debug_message(" Condition is: "+condition)
|
||||
parsed_condition = parse_condition(condition[1:-1], allowed_conditions)
|
||||
if not parsed_condition[2]=="":
|
||||
return [[], [], parse_position, parsed_condition[2]]
|
||||
parse_position = parse_position+len(condition)
|
||||
contained_code_length = get_length_of_contained_code(code[parse_position:])
|
||||
if contained_code_length == -1:
|
||||
debug_message(" Missing (")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find '(' for contained code"]
|
||||
if contained_code_length == -2:
|
||||
debug_message(" Mismatched ()")
|
||||
return [[], [], parse_position, "Syntax error: Cannot not find matching ')' for this '('"]
|
||||
contained_code = code[parse_position:parse_position+contained_code_length]
|
||||
debug_message(" Contained code: "+contained_code)
|
||||
parsed_contained_code = parse_code(contained_code[1:-1], allowed_commands, allowed_conditions, unformatted_code=False)
|
||||
if not parsed_contained_code[2]==-1:
|
||||
debug_message(" Error while parsing contained code")
|
||||
return [[], [], parse_position+1+parsed_contained_code[2], parsed_contained_code[3]]
|
||||
parse_position = parse_position+contained_code_length+1
|
||||
|
||||
parsed_code[1].append((parsed_condition, parsed_contained_code))
|
||||
parsed_code[0].append(command_while)
|
||||
else:
|
||||
debug_message(" Type: unknown control structure: "+control_structure)
|
||||
#TODO: better error message (especially when special chars are detected inside control_structure or a known command)
|
||||
return [[], [], parse_position, "Syntax error: Unknown control structure: "+control_structure]
|
||||
return parsed_code
|
||||
|
||||
# returns success or error message
|
||||
# Parsed code is the result of running the parser.
|
||||
def run_code(parsed_code):
|
||||
return ""
|
||||
|
||||
if __name__ == "__main__":
|
||||
pass
|
||||
Loading…
Reference in New Issue