lang: ast: re-factor condition group parser

this parser now only handles if-else statements, and uses the state init callback argument to receive any pre-existing inline expressions

lang/ast/cond.c

@@ -1,11 +1,22 @@
-#include "cond.h"
 #include "block.h"
 #include "expr/expr.h"
 
+struct cond_group_parser_state {
+	struct parser_state s_base;
+	bool s_inline;
+	unsigned int s_prev_token;
+
+	struct ivy_ast_cond_node *s_cur_branch;
+	b_queue s_branches;
+
+	struct ivy_ast_node *s_prev_node;
+};
+
 static void init_state(struct ivy_parser *ctx, struct parser_state *sp, uintptr_t arg)
 {
 	struct cond_group_parser_state *state
 		= (struct cond_group_parser_state *)sp;
+	state->s_prev_node = (struct ivy_ast_node *)arg;
 }
 
 struct token_parse_result parse_if(
@@ -26,11 +37,11 @@ struct token_parse_result parse_if(
 
 	if (state->s_prev_node) {
 		/* this is an inline if-else */
-		state->s_type = COND_GROUP_INLINE_IF_ELSE;
+		state->s_inline = true;
 		state->s_cur_branch->n_body = state->s_prev_node;
 		state->s_prev_node = NULL;
 	} else {
-		state->s_type = COND_GROUP_IF_ELSE;
+		state->s_inline = false;
 	}
 
 	struct expr_parser_state *expr
@@ -63,7 +74,6 @@ static enum ivy_status flush_current_branch(struct cond_group_parser_state *stat
 
 struct token_parse_result parse_then(struct ivy_parser *ctx, struct ivy_token *tok)
 {
-	enum ivy_status status;
 	struct cond_group_parser_state *state
 		= parser_get_state(ctx, struct cond_group_parser_state);
 
@@ -71,7 +81,7 @@ struct token_parse_result parse_then(struct ivy_parser *ctx, struct ivy_token *t
 		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
 	}
 
-	if (state->s_type != COND_GROUP_IF_ELSE) {
+	if (state->s_inline) {
 		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
 	}
 
@@ -89,7 +99,7 @@ struct token_parse_result parse_then(struct ivy_parser *ctx, struct ivy_token *t
 
 	/* next component will be a block. */
 	struct block_parser_state *block
-		= (struct expr_parser_state *)parser_push_state(
+		= (struct block_parser_state *)parser_push_state(
 			ctx, IVY_AST_BLOCK, 0);
 	/* set the sub-expression depth to be non-zero so the expression parser doesn't consume the expression separator. */
 	block->s_terminator = IVY_KW_END;
@@ -108,8 +118,7 @@ struct token_parse_result parse_else(struct ivy_parser *ctx, struct ivy_token *t
 		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
 	}
 
-	switch (state->s_type) {
+	if (!state->s_inline) {
-	case COND_GROUP_IF_ELSE:
 		/* previous component was either an expression or a block, and is the if branch body. */
 		if (!state->s_prev_node) {
 			return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
@@ -128,8 +137,7 @@ struct token_parse_result parse_else(struct ivy_parser *ctx, struct ivy_token *t
 		}
 
 		/* next component should either be an if keyword or a block. */
-		break;
+	} else {
-	case COND_GROUP_INLINE_IF_ELSE:
 		/* previous component was the if-condition. */
 		if (!state->s_prev_node) {
 			return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
@@ -153,9 +161,6 @@ struct token_parse_result parse_else(struct ivy_parser *ctx, struct ivy_token *t
 				ctx, IVY_AST_EXPR, 0);
 		/* set the sub-expression depth to be non-zero so the expression parser doesn't consume the expression separator. */
 		expr->s_subexpr_depth = 1;
-		break;
-	default:
-		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
 	}
 
 	state->s_prev_token = IVY_KW_ELSE;
@@ -182,8 +187,7 @@ static enum ivy_status finalise_cond_group(struct cond_group_parser_state* state
 	struct ivy_ast_cond_group_node *group
 		= (struct ivy_ast_cond_group_node *)state->s_base.s_node;
 
-	switch (state->s_type) {
+	if (state->s_inline) {
-	case COND_GROUP_INLINE_IF_ELSE:
 		/* we have just reached the end of either the 'if' or the 'else' expression. */
 		if (!state->s_cur_branch) {
 			/* not currently parsing a conditional branch. */
@@ -209,7 +213,7 @@ static enum ivy_status finalise_cond_group(struct cond_group_parser_state* state
 		group->n_branches = state->s_branches;
 		state->s_branches = B_QUEUE_INIT;
 		return IVY_OK;
-	case COND_GROUP_IF_ELSE:
+	} else {
 		/* we have just reached the 'end' keyword. */
 		if (!state->s_cur_branch) {
 			/* not currently parsing a conditional branch. */
@@ -228,8 +232,6 @@ static enum ivy_status finalise_cond_group(struct cond_group_parser_state* state
 		group->n_branches = state->s_branches;
 		state->s_branches = B_QUEUE_INIT;
 		return IVY_OK;
-	default:
-		return IVY_ERR_NOT_SUPPORTED;
 	}
 }
 
@@ -239,7 +241,7 @@ struct token_parse_result parse_punct_terminator(
 	struct cond_group_parser_state *state
 		= parser_get_state(ctx, struct cond_group_parser_state);
 
-	if (state->s_type != COND_GROUP_INLINE_IF_ELSE) {
+	if (!state->s_inline) {
 		/* only inline conditional can be ended with punctuation. */
 		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
 	}
@@ -258,8 +260,8 @@ struct token_parse_result parse_end(struct ivy_parser *ctx, struct ivy_token *to
 	struct cond_group_parser_state *state
 		= parser_get_state(ctx, struct cond_group_parser_state);
 
-	if (state->s_type == COND_GROUP_INLINE_IF_ELSE) {
+	if (state->s_inline) {
-		/* inline if-else must be terminateed with punctuation. */
+		/* inline if-else must be terminated with punctuation. */
 		return PARSE_RESULT(IVY_ERR_BAD_SYNTAX, 0);
 	}
 

lang/ast/cond.h

@@ -1,25 +0,0 @@
-#ifndef _AST_COND_H_
-#define _AST_COND_H_
-
-#include "ctx.h"
-#include "node.h"
-
-enum cond_group_type {
-	COND_GROUP_NONE = 0,
-	COND_GROUP_IF_ELSE,
-	COND_GROUP_INLINE_IF_ELSE,
-	COND_GROUP_MATCH,
-};
-
-struct cond_group_parser_state {
-	struct parser_state s_base;
-	enum cond_group_type s_type;
-	unsigned int s_prev_token;
-
-	struct ivy_ast_cond_node *s_cur_branch;
-	b_queue s_branches;
-
-	struct ivy_ast_node *s_prev_node;
-};
-
-#endif

lang/ast/expr/stmt.c

@@ -1,6 +1,5 @@
 #include "../node.h"
 #include "expr.h"
-#include "../cond.h"
 
 #include <blue/object/string.h>
 #include <ivy/lang/lex.h>
@@ -35,13 +34,12 @@ struct token_parse_result stmt_parse_if(
 		parser_pop_state(ctx, 0);
 	}
 
-	struct cond_group_parser_state *cond
-		= (struct cond_group_parser_state *)parser_push_state(
-			ctx, IVY_AST_COND_GROUP, 0);
-
 	/* if expr is NULL, this is an if-then-else-end statement,
 	 * otherwise, this is an expr-if-else-expr. */
-	cond->s_prev_node = expr;
+	struct cond_group_parser_state *cond
+		= (struct cond_group_parser_state *)parser_push_state(
+			ctx, IVY_AST_COND_GROUP, (uintptr_t)expr);
+
 	return PARSE_RESULT(IVY_OK, PARSE_REPEAT_TOKEN);
 }