def find_index(token_list, want, start=0):
for i in range(start, len(token_list)):
token = token_list[i].string
if token == want:
return i
raise exceptions.SyntaxNotMatched()
def check_for(line, line_number):
# define the syntax of FOR-LOOP statement should be
# FOR T FROM CONST_ID TO CONST_ID STEP CONST_ID DRAW (T,T)
check_list = []
check_list.append(lexical.TokenType.FOR)
check_list.append(lexical.TokenType.T)
check_list.append(lexical.TokenType.FROM)
check_list.append(lexical.TokenType.CONST_ID)
check_list.append(lexical.TokenType.TO)
check_list.append(lexical.TokenType.CONST_ID)
check_list.append(lexical.TokenType.STEP)
check_list.append(lexical.TokenType.CONST_ID)
check_list.append(lexical.TokenType.DRAW)
check_list.append(lexical.TokenType.L_BRACKET)
check_list.append(lexical.TokenType.T)
check_list.append(lexical.TokenType.COMMA)
check_list.append(lexical.TokenType.T)
check_list.append(lexical.TokenType.R_BRACKET)
length = len(check_list)
idx = 0
for token in line:
if token.token_type == check_list[idx]:
idx += 1
if idx == length:
break
if idx != length:
raise exceptions.SyntaxNotMatched(
"Syntax not matched exception in line", line_number)
def program():
lines = lexical.scanner()
results = [] # to store the information of expressions of statement
for line in lines:
dir = for_statement(line)
if dir:
results.append(dir)
print("<-------------- Structure of FOR Statement -------------->")
print("*************** Expression Tree of FROM ***************")
dir["FROM"].traverse()
print("*************** Expression Tree of TO ***************")
dir["TO"].traverse()
print("*************** Expression Tree of STEP ***************")
dir["STEP"].traverse()
print("*************** Expression Tree of X ***************")
dir["X"].traverse()
print("*************** Expression Tree of Y ***************")
dir["Y"].traverse()
continue
dir = scale_statement(line)
if dir:
results.append(dir)
print(
"<-------------- Structure of SCALE Statement -------------->")
print("*************** Expression Tree of X ***************")
dir["X"].traverse()
print("*************** Expression Tree of Y ***************")
dir["Y"].traverse()
continue
dir = rot_statement(line)
if dir:
results.append(dir)
print("<-------------- Structure of ROT Statement -------------->")
print("*************** Expression Tree of ANGLE ***************")
dir["ANGLE"].traverse()
continue
dir = origin_statement(line)
if dir:
results.append(dir)
print(
"<-------------- Structure of ORIGIN Statement -------------->"
)
print("*************** Expression Tree of X ***************")
dir["X"].traverse()
print("*************** Expression Tree of Y ***************")
dir["Y"].traverse()
continue
# if the statement is not matched, then error
raise exceptions.SyntaxNotMatched("Syntax not matched")
return {"lines": lines, "results": results}
def check_rot(line, line_number):
# define the syntax of ROT-IS statement should be
# ROT IS CONST_ID
check_list = []
check_list.append(lexical.TokenType.ROT)
check_list.append(lexical.TokenType.IS)
check_list.append(lexical.TokenType.CONST_ID)
length = len(check_list)
idx = 0
for token in line:
if token.token_type == check_list[idx]:
idx += 1
if idx == length:
break
if idx != length:
raise exceptions.SyntaxNotMatched(
"Syntax not matched exception in line", line_number)
def check_scale(line, line_number):
# define the syntax of SCALE-IS statement should be
# SCALE IS (CONST_ID,CONST_ID)
check_list = []
check_list.append(lexical.TokenType.SCALE)
check_list.append(lexical.TokenType.IS)
check_list.append(lexical.TokenType.L_BRACKET)
check_list.append(lexical.TokenType.CONST_ID)
check_list.append(lexical.TokenType.COMMA)
check_list.append(lexical.TokenType.CONST_ID)
check_list.append(lexical.TokenType.R_BRACKET)
length = len(check_list)
idx = 0
for token in line:
if token.token_type == check_list[idx]:
idx += 1
if idx == length:
break
if idx != length:
raise exceptions.SyntaxNotMatched(
"Syntax not matched exception in line", line_number)
def match_token(token, want):
# statement to debug
# print(token, want)
if token != want:
raise exceptions.SyntaxNotMatched()