diff options
Diffstat (limited to 'prolog')
| -rw-r--r-- | prolog/parser.py | 68 |
1 files changed, 25 insertions, 43 deletions
diff --git a/prolog/parser.py b/prolog/parser.py index ec42b5b..456539f 100644 --- a/prolog/parser.py +++ b/prolog/parser.py @@ -3,6 +3,7 @@ import ply.yacc as yacc from .lexer import operators, tokens from .util import Token +from monkey.graph import Node # PARSER precedence = ( @@ -20,22 +21,9 @@ precedence = ( ('nonassoc', 'LBRACKET', 'RBRACKET', 'LPAREN', 'RPAREN', 'COMMA', 'SEMI', 'PIPE', 'LBRACE', 'RBRACE') ) -class Node: - def __init__(self, type, children=None, data=None): - self.type = type - self.data = data - self.children = children if children else [] - - def __str__(self): - val = self.type - if self.children: - val += ' ' + ' '.join([str(c) for c in self.children]) - val = '({})'.format(val) - return val - def make_token(p, n): lextoken = p.slice[n] - return Token(lextoken.type, lextoken.value, lextoken.lexpos) + return Node(data=Token(lextoken.type, lextoken.value, lextoken.lexpos)) def p_text_empty(p): 'text : ' @@ -43,7 +31,7 @@ def p_text_empty(p): def p_text_clause(p): 'text : text clause' p[0] = p[1] - p[0].children.append(p[2]) + p[0].eout.append(p[2]) def p_clause_head(p): 'clause : head PERIOD' @@ -53,7 +41,7 @@ def p_clause_rule(p): p[0] = Node('clause', [p[1], make_token(p, 2), p[3], make_token(p, 4)]) def p_clause_error(p): 'clause : error PERIOD' - p[0] = Node('error') + p[0] = Node('clause', [Node('error'), make_token(p, 2)]) def p_head(p): 'head : term' @@ -64,12 +52,12 @@ def p_or_single(p): p[0] = p[1] def p_or_if(p): 'or : or SEMI if' - if p[1].type == 'or': + if p[1].data == 'or': p[0] = p[1] else: p[0] = Node('or', [p[1]]) - p[0].children.append(make_token(p, 2)) - p[0].children.append(p[3]) + p[0].eout.append(make_token(p, 2)) + p[0].eout.append(p[3]) def p_if_single(p): 'if : and' @@ -83,18 +71,18 @@ def p_and_single(p): p[0] = p[1] def p_and_term(p): 'and : and COMMA term' - if p[1].type == 'and': + if p[1].data == 'and': p[0] = p[1] else: p[0] = Node('and', [p[1]]) - p[0].children.append(make_token(p, 2)) - p[0].children.append(p[3]) + p[0].eout.append(make_token(p, 2)) + p[0].eout.append(p[3]) def p_term_functor(p): 'term : functor LPAREN args RPAREN' # No whitespace allowed between functor and LPAREN. t2 = make_token(p, 2) - if p[1].children[0].pos + len(p[1].children[0].val) < t2.pos: + if p[1].eout[0].data.pos + len(p[1].eout[0].data.val) < t2.data.pos: raise SyntaxError('whitespace before ' + str(t2)) p[0] = Node('term', [p[1], t2, p[3], make_token(p, 4)]) def p_term_or(p): @@ -152,31 +140,25 @@ def p_args_single(p): def p_args_term(p): 'args : args COMMA term' p[0] = p[1] - p[0].children.append(make_token(p, 2)) - p[0].children.append(p[3]) - -def p_list_empty(p): - 'list : LBRACKET RBRACKET' - p[0] = Node('list', [make_token(p, 1), make_token(p, 2)]) -def p_list_term(p): - 'list : LBRACKET listexpr RBRACKET' - p[0] = Node('list', [make_token(p, 1), p[2], make_token(p, 3)]) -def p_listexpr_single(p): - 'listexpr : term' - p[0] = Node('listexpr', [p[1]]) -def p_listexpr_term(p): - 'listexpr : term COMMA listexpr' - p[0] = Node('listexpr', [p[1], make_token(p, 2), p[3]]) -def p_listexpr_pipe(p): - 'listexpr : term PIPE term' - p[0] = Node('listexpr', [p[1], make_token(p, 2), p[3]]) + p[0].eout.append(make_token(p, 2)) + p[0].eout.append(p[3]) + +def p_list(p): + 'list : LBRACKET args RBRACKET' + p[0] = Node('list', [make_token(p, 1)] + p[2].eout + [make_token(p, 3)]) +def p_list_tail(p): + 'list : LBRACKET args PIPE term RBRACKET' + p[0] = Node('list', [make_token(p, 1)] + p[2].eout + [make_token(p, 3), p[4], make_token(p, 5)]) def p_functor(p): 'functor : NAME' p[0] = Node('functor', [make_token(p, 1)]) -def p_error(p): - print('Syntax error in input: ' + str(p)) +def p_error(t): + if t is None: + print('unexpected end of file') + else: + print('{}: unexpected {}'.format(t.lexpos, t.value)) parser = yacc.yacc() |