lang: ast: re-factor expression parser into multiple files

lang/ast/expr/expr.h

@@ -0,0 +1,97 @@
+#ifndef _AST_EXPR_EXPR_H_
+#define _AST_EXPR_EXPR_H_
+
+#include "../ctx.h"
+#include "../node.h"
+
+#include <blue/core/queue.h>
+
+struct ivy_ast_node;
+struct ivy_ast_msg_node;
+
+enum expr_type {
+	EXPR_TYPE_NONE = 0,
+	/* if-else, while/for, match, etc (any expression that ends with an
+	 * 'end' keyword */
+	EXPR_TYPE_STMT,
+	/* arithmetic and message-sending expressions (any expression that ends
+	 * implicitly or with an expression separator */
+	EXPR_TYPE_ARITH,
+};
+
+enum expr_subtype {
+	EXPR_SUBTYPE_NONE = 0,
+	/* generic parenthesis-enclosed arithmetic expressions */
+	EXPR_SUBTYPE_PAREN,
+	/* keyword messages */
+	EXPR_SUBTYPE_KEYWORD_MSG,
+	/* expression delimited by labels */
+	EXPR_SUBTYPE_KEYWORD_ARG,
+	/* complex messages */
+	EXPR_SUBTYPE_COMPLEX_MSG,
+};
+
+enum expr_component {
+	EXPR_CMP_NONE = 0,
+	EXPR_CMP_OPERATOR,
+	EXPR_CMP_OPERAND,
+	EXPR_CMP_MSG,
+};
+
+struct expr_parser_state {
+	struct parser_state s_base;
+	enum expr_type s_type;
+	/* for arithmetic expressions, this records whether the previous
+	 * component (either a token or parenthesised group of tokens) is an
+	 * operator, operand, or message */
+	enum expr_component s_prev_component;
+	/* the token type/keyword type/symbol type of the last token that was
+	 * encountered */
+	unsigned int s_prev_token;
+	/* if this is an arithmetic expression, this variable is the depth
+	 * of parentheses that this sub-expression is at */
+	unsigned int s_paren_depth;
+
+	/* when this is set, the expression will be terminated when the
+	 * specified token is encountered. the token that terminated the
+	 * expression will not be consumed. */
+	unsigned int s_terminator;
+
+	/* all sub-expressions (i.e. those conatained within brackets,
+	 * keyword-messages and keyword-message args, etc) will have this set/ */
+	enum expr_subtype s_subexpr;
+
+	b_queue s_output_queue;
+	b_queue s_operator_stack;
+
+	/* these variables are for keyword-message expressions */
+	struct ivy_ast_node *s_recipient;
+	struct ivy_ast_msg_node *s_msg;
+	b_queue s_labels;
+	b_queue s_args;
+};
+
+extern void arith_push_operator(
+	struct expr_parser_state *state, struct ivy_ast_node *node);
+extern void arith_push_operand(
+	struct expr_parser_state *state, struct ivy_token *tok);
+
+extern enum ivy_status arith_add_child(
+	struct parser_state *parent, struct ivy_ast_node *child);
+
+extern struct token_parse_result arith_parse_ident(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+extern struct token_parse_result arith_parse_operand(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+extern struct token_parse_result arith_parse_operator(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+extern struct token_parse_result arith_parse_label(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+extern struct token_parse_result arith_parse_left_paren(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+extern struct token_parse_result arith_parse_right_paren(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+extern struct token_parse_result arith_parse_dot(
+	struct ivy_parser *ctx, struct ivy_token *tok);
+
+#endif