/repo: ply-3.8/test/yacc_noerror.py comparison

<ais523> ` tar -xf ply-3.8.tar.gz

comparison

equal deleted inserted replaced

-:61a39a120dee
+:343ff337a19b
+# -----------------------------------------------------------------------------
+# yacc_noerror.py
+#
+# No p_error() rule defined.
+# -----------------------------------------------------------------------------
+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
+yacc.yacc()

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