parse: implement parsing of arithmetic expressions and data structures
This commit is contained in:
+883
-8
@@ -1,27 +1,902 @@
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#include "../../debug.h"
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#include "../../operator.h"
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#include "../syntax.h"
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#include <fx/queue.h>
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enum expr_component {
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EXPR_C_NONE = 0,
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EXPR_C_OPERAND,
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EXPR_C_BINARY_OP,
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EXPR_C_UNARY_OP,
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};
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struct expr_parse_ctx {
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fx_queue expr_operator_stack, expr_out_queue;
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enum expr_component expr_prev;
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unsigned int expr_prev_symbol;
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enum operator_precedence expr_minimum_precedence;
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bool expr_done, expr_fail;
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};
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static bool op_node_is_complete(struct op_ast_node *node)
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{
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if (!node->n_op) {
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return false;
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}
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switch (node->n_op->op_arity) {
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case OPA_UNARY:
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return node->n_right != NULL;
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case OPA_BINARY:
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return (node->n_left != NULL && node->n_right != NULL);
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default:
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return false;
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}
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}
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static bool finalise_expr(
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struct expr_parse_ctx *ctx,
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struct ast_node **out,
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enum operator_precedence minimum_precedence)
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{
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fx_queue_entry *entry = NULL;
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while (true) {
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entry = fx_queue_pop_back(&ctx->expr_operator_stack);
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if (!entry) {
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break;
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}
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struct op_ast_node *node
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= fx_unbox(struct op_ast_node, entry, n_base.n_entry);
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if (!node) {
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/* this should never happen */
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return false;
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}
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const struct operator_info *op = node->n_op;
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/* if we aren't processing operators below a certain precedence
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* then leave them on the stack and stop here. */
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if (op->op_precedence < minimum_precedence) {
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fx_queue_push_back(&ctx->expr_operator_stack, entry);
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break;
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}
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fx_queue_push_back(&ctx->expr_out_queue, entry);
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}
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fx_queue q = FX_QUEUE_INIT;
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fx_queue_entry *tmp = NULL;
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entry = fx_queue_first(&ctx->expr_out_queue);
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int i = 0;
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while (entry) {
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struct ast_node *item
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= fx_unbox(struct ast_node, entry, n_entry);
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fx_queue_entry *next = fx_queue_next(entry);
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fx_queue_delete(&ctx->expr_out_queue, entry);
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/* if the node is an operand, just push it to a
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* temporary queue and come back to it later. */
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if (item->n_type != AST_OP) {
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/* operand */
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fx_queue_push_back(&q, &item->n_entry);
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goto next;
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}
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const struct operator_info *op = NULL;
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struct op_ast_node *op_node = (struct op_ast_node *)item;
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/* if an operator node is already complete (i.e. it
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* already has all the operands it needs, it can be
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* pushed to the operand queue as-is */
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if (op_node_is_complete(op_node)) {
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fx_queue_push_back(&q, &item->n_entry);
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goto next;
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}
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/* otherwise, pop the relevant operands from the operand
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* queue... */
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op = op_node->n_op;
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tmp = fx_queue_pop_back(&q);
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op_node->n_right = fx_unbox(struct ast_node, tmp, n_entry);
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if (op_node->n_right) {
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op_node->n_right->n_parent = (struct ast_node *)op_node;
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#if 0
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ast_node_extend_bounds_recursive(
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(struct ivy_ast_node *)op_node,
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(struct ivy_ast_node *)tmp);
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#endif
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}
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if (op->op_arity == OPA_BINARY) {
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tmp = fx_queue_pop_back(&q);
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op_node->n_left
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= fx_unbox(struct ast_node, tmp, n_entry);
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if (op_node->n_left) {
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op_node->n_left->n_parent
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= (struct ast_node *)op_node;
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#if 0
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ast_node_extend_bounds_recursive(
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(struct ivy_ast_node *)op_node,
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(struct ivy_ast_node *)tmp);
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#endif
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}
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}
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/* ...and push the newly-completed operator node to the
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* operand queue */
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fx_queue_push_back(&q, &op_node->n_base.n_entry);
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next:
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entry = next;
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}
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#if 0
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debug_printf("** after hierarchisation:\n");
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print_expr_queues(state);
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#endif
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/* if we are not processing operators below a certain precedence,
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* i.e. when determining the recipient of a keyword-message), these
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* operators will still be on the parser state's operator stack, but
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* their operands have just been moved to the temporary operand stack
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* used above. move them back to the parser state's output queue here
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* so they can be used later. */
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entry = fx_queue_first(&ctx->expr_operator_stack);
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while (entry) {
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fx_queue_entry *entry2 = fx_queue_pop_front(&q);
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if (!entry2) {
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return false;
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}
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fx_queue_push_back(&ctx->expr_out_queue, entry2);
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entry = fx_queue_next(entry);
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}
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#if 0
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debug_printf("** after de-linearisation:\n");
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print_expr_queues(state);
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ivy_ast_node_print(*expr_tree);
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debug_printf("------\n");
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#endif
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/* the final node remaining on the temp operand stack is the
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* root node of the new expression tree */
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tmp = fx_queue_pop_back(&q);
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*out = fx_unbox(struct ast_node, tmp, n_entry);
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return true;
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}
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bool peek_arith_expr(struct parse_ctx *ctx)
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{
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switch (peek_token_type(ctx)) {
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case TOK_SYMBOL:
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switch (peek_unknown_symbol(ctx)) {
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case SYM_PLUS:
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case SYM_HYPHEN:
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return true;
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default:
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return false;
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}
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return operator_get_by_token(peek_unknown_symbol(ctx));
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case TOK_INT:
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case TOK_DOUBLE:
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case TOK_STRING:
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case TOK_VAR:
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case TOK_STR_START:
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case TOK_OPERATOR:
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return true;
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default:
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return false;
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}
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}
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bool parse_arith_expr(struct parse_ctx *ctx, struct ast_node **out)
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static bool parse_subexpr(struct parse_ctx *ctx, struct ast_node **out)
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{
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if (!parse_symbol(ctx, SYM_LEFT_PAREN)) {
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report_error(ctx, "expected `(`");
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}
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struct ast_node *v = NULL;
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if (!parse_expr(ctx, &v)) {
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report_error(ctx, "error while parsing parenthesis expression");
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return false;
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}
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if (!parse_symbol(ctx, SYM_RIGHT_PAREN)) {
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report_error(ctx, "expected `)` after parenthesis expression");
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return false;
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}
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*out = v;
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return true;
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}
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static bool parse_stmt_block(struct parse_ctx *ctx, struct ast_node **out)
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{
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if (!parse_symbol(ctx, SYM_DOLLAR_LEFT_PAREN)) {
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report_error(ctx, "expected `$(`");
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return false;
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}
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if (parse_symbol(ctx, SYM_RIGHT_PAREN)) {
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*out = ast_node_create(AST_NULL);
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return true;
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}
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struct ast_node *v = NULL;
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if (!parse_statement_list(ctx, &v)) {
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return false;
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}
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if (!parse_symbol(ctx, SYM_RIGHT_PAREN)) {
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report_error(ctx, "expected ')' after subexpression");
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ast_node_destroy(v);
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return false;
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}
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*out = v;
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return true;
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}
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static bool parse_hashtable(struct parse_ctx *ctx, struct ast_node **out)
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{
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if (!parse_symbol(ctx, SYM_AT_LEFT_BRACE)) {
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report_error(ctx, "expected `@{`");
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return false;
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}
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parse_linefeed(ctx);
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struct hashtable_ast_node *table
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= (struct hashtable_ast_node *)ast_node_create(AST_HASHTABLE);
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if (!table) {
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ctx->p_status = BSHELL_ERR_NO_MEMORY;
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return false;
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}
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size_t nr_items = 0;
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bool ok = true;
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while (ok) {
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if (parse_symbol(ctx, SYM_RIGHT_BRACE)) {
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break;
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}
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parse_linefeed(ctx);
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struct hashtable_item_ast_node *item
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= (struct hashtable_item_ast_node *)ast_node_create(
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AST_HASHTABLE_ITEM);
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struct lex_token *tok = NULL;
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if (parse_word(ctx, &tok)) {
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struct string_ast_node *v
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= (struct string_ast_node *)ast_node_create(
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AST_STRING);
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v->n_value = tok;
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item->n_key = (struct ast_node *)v;
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} else if (!parse_arith_value(ctx, &item->n_key)) {
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report_error(ctx, "failed to parse hashtable key");
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ast_node_destroy((struct ast_node *)item);
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ok = false;
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break;
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}
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if (!parse_symbol(ctx, SYM_EQUAL)) {
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report_error(ctx, "expected `=` after hashtable key");
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ast_node_destroy((struct ast_node *)item);
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ok = false;
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break;
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}
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if (!parse_expr(ctx, &item->n_value)) {
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report_error(ctx, "failed to parse hashtable value");
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ast_node_destroy((struct ast_node *)item);
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ok = false;
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break;
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}
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fx_queue_push_back(&table->n_items, &item->n_base.n_entry);
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nr_items++;
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if (parse_symbol(ctx, SYM_RIGHT_BRACE)) {
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break;
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}
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if (!parse_linefeed(ctx) && !parse_symbol(ctx, SYM_SEMICOLON)) {
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report_error(
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ctx,
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"expected `;`, `}`, or linefeed after "
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"hashtable value");
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ok = false;
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break;
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}
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}
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if (!ok) {
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ast_node_destroy((struct ast_node *)table);
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return false;
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}
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*out = (struct ast_node *)table;
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return true;
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}
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static bool parse_array(struct parse_ctx *ctx, struct ast_node **out)
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{
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if (!parse_symbol(ctx, SYM_AT_LEFT_PAREN)) {
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report_error(ctx, "expected `@(`");
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return false;
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}
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struct array_ast_node *array
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= (struct array_ast_node *)ast_node_create(AST_ARRAY);
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if (!array) {
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ctx->p_status = BSHELL_ERR_NO_MEMORY;
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return false;
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}
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size_t nr_items = 0;
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bool ok = true;
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while (ok) {
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if (parse_symbol(ctx, SYM_RIGHT_PAREN)) {
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break;
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}
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if (nr_items && !parse_symbol(ctx, SYM_COMMA)) {
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report_error(
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ctx,
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"expected `,` or `)` after array value");
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ok = false;
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}
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struct ast_node *item = NULL;
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if (!parse_arith_value(ctx, &item)) {
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report_error(ctx, "failed to parse array item");
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ok = false;
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break;
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}
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fx_queue_push_back(&array->n_items, &item->n_entry);
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nr_items++;
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}
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if (!ok) {
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ast_node_destroy((struct ast_node *)array);
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return false;
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}
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*out = (struct ast_node *)array;
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return true;
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}
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bool parse_fstring(struct parse_ctx *ctx, struct ast_node **out)
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{
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if (peek_token_type(ctx) != TOK_STR_START) {
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return false;
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}
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discard_token(ctx);
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struct fstring_ast_node *fstring
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= (struct fstring_ast_node *)ast_node_create(AST_FSTRING);
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if (!fstring) {
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ctx->p_status = BSHELL_ERR_NO_MEMORY;
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return false;
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}
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bool ok = true;
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while (ok) {
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if (peek_token_type(ctx) == TOK_STR_END) {
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discard_token(ctx);
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break;
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}
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struct ast_node *item = NULL;
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if (!parse_arith_value(ctx, &item)) {
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ok = false;
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break;
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}
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fx_queue_push_back(&fstring->n_elements, &item->n_entry);
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}
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if (!ok) {
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ast_node_destroy((struct ast_node *)fstring);
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fstring = NULL;
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}
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*out = (struct ast_node *)fstring;
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return ok;
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}
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bool parse_arith_value(struct parse_ctx *ctx, struct ast_node **out)
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{
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struct lex_token *tok = peek_token(ctx);
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switch (tok->tok_type) {
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case TOK_INT: {
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struct int_ast_node *v
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= (struct int_ast_node *)ast_node_create(AST_INT);
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v->n_value = claim_token(ctx);
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*out = (struct ast_node *)v;
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return true;
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}
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case TOK_DOUBLE: {
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struct double_ast_node *v
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= (struct double_ast_node *)ast_node_create(AST_DOUBLE);
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v->n_value = claim_token(ctx);
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*out = (struct ast_node *)v;
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return true;
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}
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case TOK_STRING: {
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struct string_ast_node *v
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= (struct string_ast_node *)ast_node_create(AST_STRING);
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v->n_value = claim_token(ctx);
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*out = (struct ast_node *)v;
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return true;
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}
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case TOK_VAR: {
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struct var_ast_node *v
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= (struct var_ast_node *)ast_node_create(AST_VAR);
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v->n_ident = claim_token(ctx);
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*out = (struct ast_node *)v;
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return true;
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}
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case TOK_STR_START:
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return parse_fstring(ctx, out);
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case TOK_SYMBOL:
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switch (tok->tok_symbol) {
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case SYM_LEFT_PAREN:
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return parse_subexpr(ctx, out);
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case SYM_DOLLAR_LEFT_PAREN:
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return parse_stmt_block(ctx, out);
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case SYM_AT_LEFT_BRACE:
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return parse_hashtable(ctx, out);
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case SYM_AT_LEFT_PAREN:
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return parse_array(ctx, out);
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case SYM_LEFT_BRACE:
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return parse_block(ctx, out);
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default:
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report_error(ctx, "token is not a valid operand");
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return false;
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}
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break;
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default:
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report_error(ctx, "token is not a valid operand");
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return false;
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}
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}
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static bool parse_operand(struct parse_ctx *ctx, struct expr_parse_ctx *expr)
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{
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if (expr->expr_prev == EXPR_C_OPERAND) {
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report_error(ctx, "encountered two operands in a row");
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return false;
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}
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expr->expr_prev = EXPR_C_OPERAND;
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struct ast_node *v = NULL;
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if (!parse_arith_value(ctx, &v)) {
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return false;
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}
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fx_queue_push_back(&expr->expr_out_queue, &v->n_entry);
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return true;
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}
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void arith_push_operator(struct expr_parse_ctx *state, struct op_ast_node *node)
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{
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const struct operator_info *op = node->n_op;
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if (!op) {
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return;
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}
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while (true) {
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fx_queue_entry *top
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= fx_queue_last(&state->expr_operator_stack);
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if (!top) {
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break;
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}
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struct ast_node *top_node
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= fx_unbox(struct ast_node, top, n_entry);
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const struct operator_info *top_op = NULL;
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switch (top_node->n_type) {
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case AST_OP: {
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struct op_ast_node *op_node
|
||||
= (struct op_ast_node *)top_node;
|
||||
top_op = op_node->n_op;
|
||||
break;
|
||||
}
|
||||
default:
|
||||
return;
|
||||
}
|
||||
|
||||
if (top_op->op_precedence < op->op_precedence
|
||||
|| (top_op->op_precedence == op->op_precedence
|
||||
&& op->op_associativity != ASSOCIATIVITY_LEFT)) {
|
||||
break;
|
||||
}
|
||||
|
||||
fx_queue_delete(&state->expr_operator_stack, top);
|
||||
fx_queue_push_back(&state->expr_out_queue, top);
|
||||
}
|
||||
|
||||
fx_queue_push_back(&state->expr_operator_stack, &node->n_base.n_entry);
|
||||
}
|
||||
|
||||
static bool parse_unary_operator(
|
||||
struct parse_ctx *ctx,
|
||||
struct expr_parse_ctx *expr)
|
||||
{
|
||||
struct lex_token *tok = peek_token(ctx);
|
||||
|
||||
const struct operator_info *op = NULL;
|
||||
switch (tok->tok_type) {
|
||||
case TOK_SYMBOL:
|
||||
op = operator_get_by_token(tok->tok_symbol);
|
||||
break;
|
||||
case TOK_OPERATOR:
|
||||
switch (tok->tok_operator) {
|
||||
case TKOP_SPLIT:
|
||||
op = operator_get_by_id(OP_USPLIT);
|
||||
break;
|
||||
case TKOP_JOIN:
|
||||
op = operator_get_by_id(OP_USPLIT);
|
||||
break;
|
||||
default:
|
||||
op = operator_get_by_token(tok->tok_operator);
|
||||
break;
|
||||
}
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
if (expr->expr_prev == EXPR_C_OPERAND
|
||||
&& op->op_location == OPL_PREFIX) {
|
||||
report_error(
|
||||
ctx,
|
||||
"unexpected operand before unary "
|
||||
"operator");
|
||||
return false;
|
||||
}
|
||||
|
||||
if (!op) {
|
||||
report_error(ctx, "unknown unary operator");
|
||||
return false;
|
||||
}
|
||||
|
||||
if (op->op_precedence < expr->expr_minimum_precedence) {
|
||||
expr->expr_done = true;
|
||||
return true;
|
||||
}
|
||||
|
||||
expr->expr_prev = EXPR_C_BINARY_OP;
|
||||
|
||||
struct op_ast_node *op_node
|
||||
= (struct op_ast_node *)ast_node_create(AST_OP);
|
||||
if (!op_node) {
|
||||
return false;
|
||||
}
|
||||
|
||||
op_node->n_op = op;
|
||||
discard_token(ctx);
|
||||
arith_push_operator(expr, op_node);
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool parse_binary_operator(
|
||||
struct parse_ctx *ctx,
|
||||
struct expr_parse_ctx *expr)
|
||||
{
|
||||
struct lex_token *tok = peek_token(ctx);
|
||||
|
||||
const struct operator_info *op = NULL;
|
||||
switch (tok->tok_type) {
|
||||
case TOK_SYMBOL:
|
||||
op = operator_get_by_token(tok->tok_symbol);
|
||||
break;
|
||||
case TOK_OPERATOR:
|
||||
switch (tok->tok_operator) {
|
||||
case TKOP_SPLIT:
|
||||
op = operator_get_by_id(OP_BSPLIT);
|
||||
break;
|
||||
case TKOP_JOIN:
|
||||
op = operator_get_by_id(OP_BJOIN);
|
||||
break;
|
||||
default:
|
||||
op = operator_get_by_token(tok->tok_operator);
|
||||
break;
|
||||
}
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
if (!op) {
|
||||
report_error(ctx, "unknown binary operator");
|
||||
return false;
|
||||
}
|
||||
|
||||
if (op->op_precedence < expr->expr_minimum_precedence) {
|
||||
expr->expr_done = true;
|
||||
return true;
|
||||
}
|
||||
|
||||
if (expr->expr_prev != EXPR_C_OPERAND) {
|
||||
switch (op->op_id) {
|
||||
case OP_PAREN:
|
||||
break;
|
||||
default:
|
||||
report_error(
|
||||
ctx,
|
||||
"expected operand before binary "
|
||||
"operator");
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
expr->expr_prev = EXPR_C_BINARY_OP;
|
||||
|
||||
struct op_ast_node *op_node
|
||||
= (struct op_ast_node *)ast_node_create(AST_OP);
|
||||
if (!op_node) {
|
||||
return false;
|
||||
}
|
||||
|
||||
op_node->n_op = op;
|
||||
discard_token(ctx);
|
||||
arith_push_operator(expr, op_node);
|
||||
return true;
|
||||
}
|
||||
|
||||
static bool parse_call(struct parse_ctx *ctx, struct expr_parse_ctx *expr)
|
||||
{
|
||||
return false;
|
||||
}
|
||||
|
||||
static bool parse_comma(struct parse_ctx *ctx, struct expr_parse_ctx *expr)
|
||||
{
|
||||
if (PRECEDENCE_ARRAY < expr->expr_minimum_precedence) {
|
||||
expr->expr_done = true;
|
||||
return true;
|
||||
}
|
||||
|
||||
struct ast_node *item = NULL;
|
||||
if (!finalise_expr(expr, &item, PRECEDENCE_ARRAY)) {
|
||||
report_error(ctx, "failed to collect first array item.");
|
||||
return false;
|
||||
}
|
||||
|
||||
struct array_ast_node *array
|
||||
= (struct array_ast_node *)ast_node_create(AST_ARRAY);
|
||||
if (!array) {
|
||||
ctx->p_status = BSHELL_ERR_NO_MEMORY;
|
||||
ast_node_destroy(item);
|
||||
return false;
|
||||
}
|
||||
|
||||
if (item) {
|
||||
fx_queue_push_back(&array->n_items, &item->n_entry);
|
||||
}
|
||||
|
||||
while (1) {
|
||||
if (!parse_symbol(ctx, SYM_COMMA)) {
|
||||
break;
|
||||
}
|
||||
|
||||
if (!parse_arith_expr(ctx, PRECEDENCE_ARRAY + 1, &item)) {
|
||||
report_error(ctx, "failed to parse array item.");
|
||||
ast_node_destroy((struct ast_node *)array);
|
||||
return false;
|
||||
}
|
||||
|
||||
fx_queue_push_back(&array->n_items, &item->n_entry);
|
||||
}
|
||||
|
||||
fx_queue_push_back(&expr->expr_out_queue, &array->n_base.n_entry);
|
||||
expr->expr_prev = EXPR_C_OPERAND;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static void dump_expr_ctx(struct expr_parse_ctx *expr)
|
||||
{
|
||||
printf("op stack:\n");
|
||||
fx_queue_entry *entry = fx_queue_first(&expr->expr_operator_stack);
|
||||
while (entry) {
|
||||
struct ast_node *node
|
||||
= fx_unbox(struct ast_node, entry, n_entry);
|
||||
print_ast_node(node);
|
||||
entry = fx_queue_next(entry);
|
||||
}
|
||||
|
||||
printf("out queue:\n");
|
||||
entry = fx_queue_first(&expr->expr_out_queue);
|
||||
while (entry) {
|
||||
struct ast_node *node
|
||||
= fx_unbox(struct ast_node, entry, n_entry);
|
||||
print_ast_node(node);
|
||||
entry = fx_queue_next(entry);
|
||||
}
|
||||
}
|
||||
|
||||
static bool can_use_command(struct expr_parse_ctx *ctx)
|
||||
{
|
||||
switch (ctx->expr_prev_symbol) {
|
||||
case TOK_NONE:
|
||||
case SYM_EQUAL:
|
||||
case SYM_PLUS_EQUAL:
|
||||
case SYM_HYPHEN_EQUAL:
|
||||
case SYM_ASTERISK_EQUAL:
|
||||
case SYM_FORWARD_SLASH_EQUAL:
|
||||
case SYM_PERCENT_EQUAL:
|
||||
return true;
|
||||
default:
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
bool parse_arith_expr(
|
||||
struct parse_ctx *ctx,
|
||||
enum operator_precedence minimum_precedence,
|
||||
struct ast_node **out)
|
||||
{
|
||||
struct expr_parse_ctx expr = {
|
||||
.expr_minimum_precedence = minimum_precedence,
|
||||
};
|
||||
|
||||
while (!expr.expr_fail && !expr.expr_done) {
|
||||
struct lex_token *tok = peek_token(ctx);
|
||||
if (!tok) {
|
||||
break;
|
||||
}
|
||||
|
||||
switch (tok->tok_type) {
|
||||
case TOK_LINEFEED:
|
||||
expr.expr_done = true;
|
||||
break;
|
||||
case TOK_WORD: {
|
||||
if (!can_use_command(&expr)) {
|
||||
report_error(
|
||||
ctx,
|
||||
"expected a value expression");
|
||||
expr.expr_fail = true;
|
||||
break;
|
||||
}
|
||||
|
||||
struct ast_node *value = NULL;
|
||||
if (!parse_command(ctx, &value)) {
|
||||
expr.expr_fail = true;
|
||||
break;
|
||||
}
|
||||
|
||||
fx_queue_push_back(
|
||||
&expr.expr_out_queue,
|
||||
&value->n_entry);
|
||||
break;
|
||||
}
|
||||
|
||||
case TOK_VAR:
|
||||
case TOK_INT:
|
||||
case TOK_DOUBLE:
|
||||
case TOK_STRING:
|
||||
case TOK_STR_START:
|
||||
expr.expr_fail = !parse_operand(ctx, &expr);
|
||||
expr.expr_prev_symbol = tok->tok_type;
|
||||
break;
|
||||
case TOK_OPERATOR:
|
||||
switch (tok->tok_operator) {
|
||||
/* these two are special cases, as they are both
|
||||
* unary AND binary operators */
|
||||
case TKOP_SPLIT:
|
||||
case TKOP_JOIN:
|
||||
if (expr.expr_prev == EXPR_C_OPERAND) {
|
||||
expr.expr_fail = !parse_binary_operator(
|
||||
ctx,
|
||||
&expr);
|
||||
} else {
|
||||
expr.expr_fail = !parse_unary_operator(
|
||||
ctx,
|
||||
&expr);
|
||||
}
|
||||
|
||||
break;
|
||||
case TKOP_BNOT:
|
||||
case TKOP_NOT:
|
||||
expr.expr_fail
|
||||
= !parse_unary_operator(ctx, &expr);
|
||||
break;
|
||||
default:
|
||||
expr.expr_fail
|
||||
= !parse_binary_operator(ctx, &expr);
|
||||
break;
|
||||
}
|
||||
expr.expr_prev_symbol = tok->tok_operator;
|
||||
break;
|
||||
case TOK_SYMBOL:
|
||||
switch (tok->tok_symbol) {
|
||||
case SYM_SEMICOLON:
|
||||
case SYM_AMPERSAND:
|
||||
case SYM_PIPE:
|
||||
case SYM_RIGHT_PAREN:
|
||||
case SYM_RIGHT_BRACE:
|
||||
case SYM_RIGHT_BRACKET:
|
||||
expr.expr_done = true;
|
||||
break;
|
||||
case SYM_COMMA:
|
||||
expr.expr_fail = !parse_comma(ctx, &expr);
|
||||
break;
|
||||
case SYM_LEFT_PAREN: {
|
||||
if (expr.expr_prev == EXPR_C_OPERAND) {
|
||||
return parse_call(ctx, &expr);
|
||||
}
|
||||
|
||||
struct ast_node *v = NULL;
|
||||
expr.expr_fail = !parse_subexpr(ctx, &v);
|
||||
if (expr.expr_fail) {
|
||||
break;
|
||||
}
|
||||
|
||||
fx_queue_push_back(
|
||||
&expr.expr_out_queue,
|
||||
&v->n_entry);
|
||||
expr.expr_prev = EXPR_C_OPERAND;
|
||||
break;
|
||||
}
|
||||
case SYM_DOLLAR_LEFT_PAREN:
|
||||
case SYM_AT_LEFT_PAREN:
|
||||
case SYM_AT_LEFT_BRACE:
|
||||
expr.expr_fail = !parse_operand(ctx, &expr);
|
||||
break;
|
||||
default: {
|
||||
const struct operator_info *op
|
||||
= operator_get_by_token(
|
||||
tok->tok_symbol);
|
||||
if (op->op_arity == OPA_BINARY) {
|
||||
expr.expr_fail = !parse_binary_operator(
|
||||
ctx,
|
||||
&expr);
|
||||
} else {
|
||||
expr.expr_fail = !parse_unary_operator(
|
||||
ctx,
|
||||
&expr);
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
expr.expr_prev_symbol = tok->tok_symbol;
|
||||
break;
|
||||
default:
|
||||
report_error(
|
||||
ctx,
|
||||
"unexpected token in arithmetic "
|
||||
"expression");
|
||||
expr.expr_fail = true;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (expr.expr_fail) {
|
||||
/* TODO cleanup */
|
||||
return false;
|
||||
}
|
||||
|
||||
struct ast_node *value = NULL;
|
||||
if (!finalise_expr(&expr, &value, PRECEDENCE_ASSIGN)) {
|
||||
report_error(ctx, "failed to convert expression to AST");
|
||||
/* TODO cleanup */
|
||||
return false;
|
||||
}
|
||||
|
||||
if (PRECEDENCE_PIPELINE >= expr.expr_minimum_precedence) {
|
||||
if (peek_symbol(ctx, SYM_PIPE)) {
|
||||
return parse_pipeline(ctx, value, out);
|
||||
}
|
||||
}
|
||||
|
||||
*out = value;
|
||||
return true;
|
||||
}
|
||||
|
||||
@@ -0,0 +1,15 @@
|
||||
#include "../syntax.h"
|
||||
|
||||
bool parse_expr(struct parse_ctx *ctx, struct ast_node **out)
|
||||
{
|
||||
bool ok = false;
|
||||
if (!ok && peek_arith_expr(ctx)) {
|
||||
ok = parse_arith_expr(ctx, PRECEDENCE_MINIMUM, out);
|
||||
}
|
||||
|
||||
if (!ok && peek_command(ctx)) {
|
||||
ok = parse_command(ctx, out);
|
||||
}
|
||||
|
||||
return ok;
|
||||
}
|
||||
Reference in New Issue
Block a user