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view ply-3.8/test/yacc_error1.py @ 12508:335a2a849232 draft default tip
<wib_jonas> `` f=/hackenv/bin/dateu; >$f echo $\'#!/bin/bash\\nset -e\\nif (( 1 < $# )); then echo "dateu error: too many command-line arguments. Usage: dateu datetimestring"; exit 2; fi\\nexec date -u ${1:+-d "$1"} "+%Y-%m-%d %H:%M:%S.%3N %z %Z %B %-e %A %G-W%V-%u"\'; chmod a+x "$f"
author | HackEso <hackeso@esolangs.org> |
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date | Wed, 03 Jul 2024 18:15:24 +0100 |
parents | 343ff337a19b |
children |
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# ----------------------------------------------------------------------------- # yacc_error1.py # # Bad p_error() function # ----------------------------------------------------------------------------- import sys if ".." not in sys.path: sys.path.insert(0,"..") import ply.yacc as yacc from calclex import tokens # Parsing rules precedence = ( ('left','PLUS','MINUS'), ('left','TIMES','DIVIDE'), ('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,s): print("Syntax error at '%s'" % t.value) yacc.yacc()