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view ply-3.8/test/yacc_prec1.py @ 11700:1a1efbb43242 draft
<b_jonas> `` set -e; cd share/mtg; iconv -f cp1252 -t utf-8 MagicCompRules_20190125.txt | tr -d \\\\r > rules.txt
author | HackEso <hackeso@esolangs.org> |
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date | Sat, 26 Jan 2019 23:00:43 +0000 |
parents | 343ff337a19b |
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# ----------------------------------------------------------------------------- # yacc_prec1.py # # Tests case where precedence specifier doesn't match up to terminals # ----------------------------------------------------------------------------- import sys if ".." not in sys.path: sys.path.insert(0,"..") import ply.yacc as yacc from calclex import tokens # Parsing rules precedence = ( ('left', '+', '-'), ('left', '*', '/'), ('right','UMINUS'), ) # dictionary of names names = { } def p_statement_assign(t): 'statement : NAME EQUALS expression' names[t[1]] = t[3] def p_statement_expr(t): 'statement : expression' print(t[1]) def p_expression_binop(t): '''expression : expression PLUS expression | expression MINUS expression | expression TIMES expression | expression DIVIDE expression''' if t[2] == '+' : t[0] = t[1] + t[3] elif t[2] == '-': t[0] = t[1] - t[3] elif t[2] == '*': t[0] = t[1] * t[3] elif t[2] == '/': t[0] = t[1] / t[3] def p_expression_uminus(t): 'expression : MINUS expression %prec UMINUS' t[0] = -t[2] def p_expression_group(t): 'expression : LPAREN expression RPAREN' t[0] = t[2] def p_expression_number(t): 'expression : NUMBER' t[0] = t[1] def p_expression_name(t): 'expression : NAME' try: t[0] = names[t[1]] except LookupError: print("Undefined name '%s'" % t[1]) t[0] = 0 def p_error(t): print("Syntax error at '%s'" % t.value) yacc.yacc()