lang: lex: start implementing strings and interpolation

lang/lex.c

@@ -15,6 +15,17 @@
 		.id = (i), .name = (n)                                         \
 	}
 
+enum lexer_state_type {
+	STATE_NORMAL,
+	STATE_STRING,
+	STATE_FSTRING,
+	STATE_INTERPOLATION,
+};
+
+struct lexer_state {
+	enum lexer_state_type s_type;
+};
+
 struct ivy_lexer_symbol_node {
 	char s_char;
 	enum ivy_symbol s_id;
@@ -55,6 +66,8 @@ static const size_t nr_keywords = sizeof keywords / sizeof keywords[0];
 
 static struct lex_token_def symbols[] = {
 	LEX_TOKEN_DEF(IVY_SYM_DOT, "."),
+	LEX_TOKEN_DEF(IVY_SYM_SQUOTE, "'"),
+	LEX_TOKEN_DEF(IVY_SYM_DQUOTE, "\""),
 	LEX_TOKEN_DEF(IVY_SYM_LEFT_BRACE, "{"),
 	LEX_TOKEN_DEF(IVY_SYM_RIGHT_BRACE, "}"),
 	LEX_TOKEN_DEF(IVY_SYM_LEFT_BRACKET, "["),
@@ -130,6 +143,8 @@ static enum ivy_status put_symbol(
 			return IVY_ERR_NO_MEMORY;
 		}
 
+		memset(child, 0x0, sizeof *child);
+
 		child->s_id = IVY_SYM_NONE;
 		child->s_char = c;
 
@@ -403,6 +418,46 @@ static enum ivy_status push_linefeed(struct ivy_lexer *lex)
 	return push_token(lex, tok);
 }
 
+static enum ivy_status push_string_start(struct ivy_lexer *lex)
+{
+	struct ivy_token *tok = malloc(sizeof *tok);
+	if (!tok) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(tok, 0x0, sizeof *tok);
+
+	tok->t_type = IVY_TOK_STR_START;
+	return push_token(lex, tok);
+}
+
+static enum ivy_status push_string_end(struct ivy_lexer *lex)
+{
+	struct ivy_token *tok = malloc(sizeof *tok);
+	if (!tok) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(tok, 0x0, sizeof *tok);
+
+	tok->t_type = IVY_TOK_STR_END;
+	return push_token(lex, tok);
+}
+
+static enum ivy_status push_string_content(struct ivy_lexer *lex, char *s)
+{
+	struct ivy_token *tok = malloc(sizeof *tok);
+	if (!tok) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(tok, 0x0, sizeof *tok);
+
+	tok->t_type = IVY_TOK_STRING;
+	tok->t_str = s;
+	return push_token(lex, tok);
+}
+
 static enum ivy_status push_symbol(struct ivy_lexer *lex, enum ivy_symbol sym)
 {
 	struct ivy_token *tok = malloc(sizeof *tok);
@@ -480,10 +535,72 @@ static enum ivy_status read_block_comment(struct ivy_lexer *lex)
 	return IVY_OK;
 }
 
+static enum ivy_status read_squote_marker(struct ivy_lexer *lex)
+{
+	enum ivy_status status = IVY_OK;
+
+	if (lex->lex_state & STATE_FSTRING) {
+		/* already within an fstring */
+		lex->lex_state &= ~STATE_FSTRING;
+		return push_string_end(lex);	
+	} else {
+		/* start of a new fstring */
+		status = push_string_start(lex);
+		lex->lex_state |= STATE_FSTRING;
+	}
+}
+
+static enum ivy_status read_dquote_marker(struct ivy_lexer *lex)
+{
+
+}
+
+static enum ivy_status read_string_content(struct ivy_lexer *lex)
+{
+	int c;
+	b_string *str = b_string_create();
+
+	if (!str) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	while (true) {
+		c = peek(lex);
+
+		if (c == '{') {
+			break;
+		}
+
+		if ((lex->lex_state & STATE_FSTRING) && c == '\'') {
+			break;
+		}
+
+		if ((lex->lex_state & STATE_STRING) && c == '"') {
+			break;
+		}
+
+		char s[2] = {c, 0};
+		b_string_append_cstr(str, s);
+	}
+
+	if (b_string_get_size(str, B_STRLEN_NORMAL) == 0) {
+		b_string_release(str);
+		return IVY_OK;
+	}
+
+	char *s = b_string_steal(str);
+	b_string_release(str);
+
+	enum ivy_status status = push_string_content(lex, s);
+	if (status != IVY_OK) {
+		free(s);
+	}
+
+	return status;
+}
+
 static enum ivy_status read_symbol(struct ivy_lexer *lex)
 {
-	char sym_buf[32];
-	unsigned int sym_len = 0;
 	struct ivy_lexer_symbol_node *node = lex->lex_sym_tree;
 
 	while (true) {
@@ -502,14 +619,19 @@ static enum ivy_status read_symbol(struct ivy_lexer *lex)
 		return IVY_ERR_BAD_SYNTAX;
 	}
 
-	if (node->s_id == IVY_SYM_FORWARD_SLASH_ASTERISK) {
+	switch (node->s_id) {
+	case IVY_SYM_SQUOTE:
+		return read_squote_marker(lex);
+	case IVY_SYM_DQUOTE:
+		return read_dquote_marker(lex);
+	case IVY_SYM_FORWARD_SLASH_ASTERISK:
 		return read_block_comment(lex);
-	} else if (node->s_id == IVY_SYM_DOUBLE_HYPHEN) {
+	case IVY_SYM_DOUBLE_HYPHEN:
 		return read_line_comment(lex);
+	default:
+		push_symbol(lex, node->s_id);
+		return IVY_OK;
 	}
-
-	push_symbol(lex, node->s_id);
-	return IVY_OK;
 }
 
 static enum ivy_status read_ident(struct ivy_lexer *lex)
@@ -568,6 +690,14 @@ static enum ivy_status pump_tokens(struct ivy_lexer *lex)
 		return c;
 	}
 
+	if (lex->lex_state & STATE_STRING && c != '"') {
+		return read_string_content(lex);
+	}
+
+	if ((lex->lex_state & STATE_FSTRING) && !(lex->lex_state & STATE_INTERPOLATION)) {
+		return read_string_content(lex);
+	}
+
 	if (c == '\n') {
 		while (c == '\n') {
 			advance(lex);