Experiments/libabacus
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Complete the "rearrange" part of Shunting Yard in the parser.

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This commit is contained in:
Danila Fedorin 2018-02-17 16:01:04 -08:00
parent b1aa2a4bf5
commit 68b4fb5807
1 changed files with 84 additions and 13 deletions
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93
src/parser.c
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@ -77,29 +77,41 @@ int _parser_match_is_op(libab_lexer_match* match) {
match->type == TOKEN_OP_POSTFIX;
}
libab_result _parser_construct_op_node(struct parser_state* state, libab_lexer_match* match, libab_tree** into) {
libab_result _parser_construct_node_string(struct parser_state* state, libab_lexer_match* match, libab_tree** into) {
libab_result result = LIBAB_SUCCESS;
if((*into = malloc(sizeof(**into)))) {
if(((*into) = malloc(sizeof(**into)))) {
result = _parser_extract_token(state, &(*into)->string_value, match);
} else {
result = LIBAB_MALLOC;
}
if(result == LIBAB_SUCCESS) {
result = libab_convert_ds_result(vec_init(&(*into)->children));
if(result == LIBAB_SUCCESS) {
(*into)->variant = OP;
if(result != LIBAB_SUCCESS) {
free(*into);
*into = NULL;
} else {
(*into)->from = match->from;
(*into)->to = match->to;
(*into)->line = match->line;
(*into)->line_from = match->line_from;
}
return result;
}
libab_result _parser_construct_op_node(struct parser_state* state, libab_lexer_match* match, libab_tree** into) {
libab_result result = _parser_construct_node_string(state, match, into);
if(result == LIBAB_SUCCESS) {
result = libab_convert_ds_result(vec_init(&(*into)->children));
if(result == LIBAB_SUCCESS) {
(*into)->variant = OP;
} else {
free((*into)->string_value);
}
} else {
free(*into);
*into = NULL;
}
}
return result;
}
libab_result _parser_append_op_node(struct parser_state* state, libab_lexer_match* match, ll* append_to) {
@ -122,7 +134,6 @@ libab_result _parser_pop_brackets(struct parser_state* state, ll* pop_from, ll*
while(result == LIBAB_SUCCESS && _parser_match_is_op(pop_from->tail->data)) {
libab_lexer_match* new_match = ll_poptail(pop_from);
result = _parser_append_op_node(state, new_match, push_to);
free(new_match);
}
remaining_match = (pop_from->tail) ? pop_from->tail->data : NULL;
*success = remaining_match && (remaining_match->type == TOKEN_CHAR) && (state->string[remaining_match->from] == bracket);
@ -147,6 +158,43 @@ int _parser_can_postfix_follow(enum parser_expression_type type) {
return type == EXPR_CLOSE_PARENTH || type == EXPR_ATOM || type == EXPR_OP_POSTFIX;
}
libab_operator* _parser_find_operator(struct parser_state* state, libab_lexer_match* match) {
char op_buffer[8];
size_t token_size = match->to - match->from;
size_t buffer_length = (token_size < 7) ? token_size : 7;
strncpy(op_buffer, state->string + match->from, buffer_length);
op_buffer[buffer_length] = '\0';
return libab_table_search_operator(state->base_table, op_buffer);
}
libab_result _parse_atom(struct parser_state* state, libab_tree** store_into) {
libab_result result = LIBAB_SUCCESS;
if(_parser_is_type(state, TOKEN_NUM) || _parser_is_type(state, TOKEN_ID)) {
result = _parser_construct_node_string(state, state->current_match, store_into);
if(result == LIBAB_SUCCESS) {
(*store_into)->variant = (state->current_match->type == TOKEN_NUM) ? NUM : ID;
}
_parser_state_step(state);
} else {
result = LIBAB_UNEXPECTED;
}
return result;
}
libab_result _parser_append_atom(struct parser_state* state, ll* append_to) {
libab_result result = LIBAB_SUCCESS;
libab_tree* tree;
result = _parse_atom(state, &tree);
if(result == LIBAB_SUCCESS) {
result = libab_convert_ds_result(ll_append(append_to, tree));
if(result != LIBAB_SUCCESS) {
libab_tree_free(tree);
free(tree);
}
}
return result;
}
libab_result _parse_expression(struct parser_state* state, libab_tree** store_into) {
libab_result result = LIBAB_SUCCESS;
ll out_stack;
@ -170,7 +218,7 @@ libab_result _parse_expression(struct parser_state* state, libab_tree** store_in
} else if(current_char == ')') {
result = _parser_pop_brackets(state, &op_stack, &out_stack, '(', &pop_success);
if(result != LIBAB_SUCCESS || !pop_success) break;
free(ll_poptail(&op_stack));
ll_poptail(&op_stack);
_parser_state_step(state);
new_type = EXPR_CLOSE_PARENTH;
} else {
@ -184,9 +232,32 @@ libab_result _parse_expression(struct parser_state* state, libab_tree** store_in
} else if(new_token->type == TOKEN_OP_POSTFIX && _parser_can_postfix_follow(last_type)) {
result = _parser_append_op_node(state, new_token, &out_stack);
} else if(new_token->type == TOKEN_OP_INFIX) {
libab_operator* operator = _parser_find_operator(state, new_token);
_parser_state_step(state);
while(result == LIBAB_SUCCESS && op_stack.tail &&
_parser_match_is_op(op_stack.tail->data)) {
libab_operator* other_operator = _parser_find_operator(state, new_token);
if(new_token->type == TOKEN_OP_PREFIX ||
(operator->associativity == -1 &&
operator->precedence <= other_operator->precedence) ||
(operator->associativity == 1 &&
operator->precedence < other_operator->precedence)) {
libab_lexer_match* match = ll_poptail(&op_stack);
result = _parser_append_op_node(state, match, &out_stack);
} else {
break;
}
}
if(result == LIBAB_SUCCESS) {
result = libab_convert_ds_result(ll_append(&op_stack, new_token));
}
new_type = EXPR_OP_INFIX;
} else {
if(last_type == EXPR_ATOM) break;
result = _parser_append_atom(state, &out_stack);
new_type = EXPR_ATOM;
}
last_type = new_type;
}