diff options
Diffstat (limited to 'example/yply/yparse.py')
| -rw-r--r-- | example/yply/yparse.py | 153 |
1 files changed, 90 insertions, 63 deletions
diff --git a/example/yply/yparse.py b/example/yply/yparse.py index ab5b884..fff887a 100644 --- a/example/yply/yparse.py +++ b/example/yply/yparse.py @@ -9,13 +9,15 @@ tokens = ylex.tokens from ply import * tokenlist = [] -preclist = [] +preclist = [] emit_code = 1 + def p_yacc(p): '''yacc : defsection rulesection''' + def p_defsection(p): '''defsection : definitions SECTION | SECTION''' @@ -25,37 +27,43 @@ def p_defsection(p): print "precedence = ", repr(preclist) print print "# -------------- RULES ----------------" - print + print + def p_rulesection(p): '''rulesection : rules SECTION''' print "# -------------- RULES END ----------------" - print_code(p[2],0) + print_code(p[2], 0) + def p_definitions(p): '''definitions : definitions definition | definition''' + def p_definition_literal(p): '''definition : LITERAL''' - print_code(p[1],0) + print_code(p[1], 0) + def p_definition_start(p): '''definition : START ID''' print "start = '%s'" % p[2] + def p_definition_token(p): '''definition : toktype opttype idlist optsemi ''' for i in p[3]: - if i[0] not in "'\"": - tokenlist.append(i) + if i[0] not in "'\"": + tokenlist.append(i) if p[1] == '%left': preclist.append(('left',) + tuple(p[3])) elif p[1] == '%right': preclist.append(('right',) + tuple(p[3])) elif p[1] == '%nonassoc': - preclist.append(('nonassoc',)+ tuple(p[3])) + preclist.append(('nonassoc',) + tuple(p[3])) + def p_toktype(p): '''toktype : TOKEN @@ -64,10 +72,12 @@ def p_toktype(p): | NONASSOC''' p[0] = p[1] + def p_opttype(p): '''opttype : '<' ID '>' | empty''' + def p_idlist(p): '''idlist : idlist optcomma tokenid | tokenid''' @@ -77,141 +87,158 @@ def p_idlist(p): p[0] = p[1] p[1].append(p[3]) + def p_tokenid(p): '''tokenid : ID | ID NUMBER | QLITERAL | QLITERAL NUMBER''' p[0] = p[1] - + + def p_optsemi(p): '''optsemi : ';' | empty''' + def p_optcomma(p): '''optcomma : ',' | empty''' + def p_definition_type(p): '''definition : TYPE '<' ID '>' namelist optsemi''' # type declarations are ignored + def p_namelist(p): '''namelist : namelist optcomma ID | ID''' + def p_definition_union(p): '''definition : UNION CODE optsemi''' # Union declarations are ignored + def p_rules(p): '''rules : rules rule | rule''' if len(p) == 2: - rule = p[1] + rule = p[1] else: - rule = p[2] + rule = p[2] # Print out a Python equivalent of this rule - embedded = [ ] # Embedded actions (a mess) + embedded = [] # Embedded actions (a mess) embed_count = 0 rulename = rule[0] rulecount = 1 for r in rule[1]: # r contains one of the rule possibilities - print "def p_%s_%d(p):" % (rulename,rulecount) + print "def p_%s_%d(p):" % (rulename, rulecount) prod = [] prodcode = "" for i in range(len(r)): - item = r[i] - if item[0] == '{': # A code block - if i == len(r) - 1: - prodcode = item - break - else: - # an embedded action - embed_name = "_embed%d_%s" % (embed_count,rulename) - prod.append(embed_name) - embedded.append((embed_name,item)) - embed_count += 1 - else: - prod.append(item) + item = r[i] + if item[0] == '{': # A code block + if i == len(r) - 1: + prodcode = item + break + else: + # an embedded action + embed_name = "_embed%d_%s" % (embed_count, rulename) + prod.append(embed_name) + embedded.append((embed_name, item)) + embed_count += 1 + else: + prod.append(item) print " '''%s : %s'''" % (rulename, " ".join(prod)) # Emit code - print_code(prodcode,4) + print_code(prodcode, 4) print rulecount += 1 - for e,code in embedded: + for e, code in embedded: print "def p_%s(p):" % e print " '''%s : '''" % e - print_code(code,4) + print_code(code, 4) print + def p_rule(p): - '''rule : ID ':' rulelist ';' ''' - p[0] = (p[1],[p[3]]) + '''rule : ID ':' rulelist ';' ''' + p[0] = (p[1], [p[3]]) + def p_rule2(p): - '''rule : ID ':' rulelist morerules ';' ''' - p[4].insert(0,p[3]) - p[0] = (p[1],p[4]) + '''rule : ID ':' rulelist morerules ';' ''' + p[4].insert(0, p[3]) + p[0] = (p[1], p[4]) + def p_rule_empty(p): - '''rule : ID ':' ';' ''' - p[0] = (p[1],[[]]) + '''rule : ID ':' ';' ''' + p[0] = (p[1], [[]]) + def p_rule_empty2(p): - '''rule : ID ':' morerules ';' ''' - - p[3].insert(0,[]) - p[0] = (p[1],p[3]) + '''rule : ID ':' morerules ';' ''' + + p[3].insert(0, []) + p[0] = (p[1], p[3]) + def p_morerules(p): - '''morerules : morerules '|' rulelist - | '|' rulelist - | '|' ''' - - if len(p) == 2: - p[0] = [[]] - elif len(p) == 3: - p[0] = [p[2]] - else: - p[0] = p[1] - p[0].append(p[3]) + '''morerules : morerules '|' rulelist + | '|' rulelist + | '|' ''' + + if len(p) == 2: + p[0] = [[]] + elif len(p) == 3: + p[0] = [p[2]] + else: + p[0] = p[1] + p[0].append(p[3]) # print "morerules", len(p), p[0] + def p_rulelist(p): - '''rulelist : rulelist ruleitem - | ruleitem''' + '''rulelist : rulelist ruleitem + | ruleitem''' - if len(p) == 2: + if len(p) == 2: p[0] = [p[1]] - else: + else: p[0] = p[1] p[1].append(p[2]) + def p_ruleitem(p): - '''ruleitem : ID - | QLITERAL - | CODE - | PREC''' - p[0] = p[1] + '''ruleitem : ID + | QLITERAL + | CODE + | PREC''' + p[0] = p[1] + def p_empty(p): '''empty : ''' + def p_error(p): pass yacc.yacc(debug=0) -def print_code(code,indent): - if not emit_code: return + +def print_code(code, indent): + if not emit_code: + return codelines = code.splitlines() for c in codelines: - print "%s# %s" % (" "*indent,c) - + print "%s# %s" % (" " * indent, c) |