commit c22cc3608a9459db36d5b71a93613da05cf30b30
parent bcdbe9902d119248d090a75530d9a60b127bca2e
Author: kocotian <kocotian@kocotian.pl>
Date: Fri, 26 Feb 2021 21:06:00 +0100
finally a grammar, fixes, removed puts()'s, temporary expressions
Diffstat:
| M | grammar.c | | | 65 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++----------- |
1 file changed, 54 insertions(+), 11 deletions(-)
diff --git a/grammar.c b/grammar.c
@@ -26,6 +26,18 @@ g_expecttype(Token token, TokenType type)
}
size_t
+g_expression(Token *tokens, size_t toksize)
+{
+ size_t i;
+ i = 0;
+
+ /* temporarily, expression can be a number only; TODO */
+ g_expecttype(tokens[i++], TokenNumber);
+
+ return i;
+}
+
+size_t
g_statement(Token *tokens, size_t toksize)
{
size_t i;
@@ -33,14 +45,45 @@ g_statement(Token *tokens, size_t toksize)
if (tokens[i].type == TokenOpeningBrace) { /* compound */
++i;
while (tokens[i].type != TokenClosingBrace && i < toksize) {
- g_statement(tokens + i, toksize - i); ++i;
+ i += g_statement(tokens + i, toksize - i); ++i;
}
} else if (tokens[i].type == TokenKeyword) {
if (!strncmp(contents + tokens[i].off, "if", 2)) { /* conditional */
+ g_expecttype(tokens[++i], TokenOpeningParenthesis);
+ ++i;
+ i += g_expression(tokens + i, toksize - i);
+ g_expecttype(tokens[i++], TokenClosingParenthesis);
+ i += g_statement(tokens + i, toksize - i);
} else if (!strncmp(contents + tokens[i].off, "while", 5)) { /* loop */
+ g_expecttype(tokens[++i], TokenOpeningParenthesis);
+ ++i;
+ i += g_expression(tokens + i, toksize - i);
+ g_expecttype(tokens[i++], TokenClosingParenthesis);
+ i += g_statement(tokens + i, toksize - i);
} else if (!strncmp(contents + tokens[i].off, "return", 6)) { /* return */
+ ++i;
+ i += g_expression(tokens + i, toksize - i);
+ g_expecttype(tokens[i], TokenSemicolon);
} else if (!strncmp(contents + tokens[i].off, "var", 3)) { /* variable */
+ do {
+ ++i;
+ g_expecttype(tokens[i++], TokenIdentifier);
+ if (tokens[i].type == TokenEqualSign) {
+ ++i;
+ i += g_expression(tokens + i, toksize - i);
+ }
+ } while (tokens[i].type == TokenComma);
+ g_expecttype(tokens[i], TokenSemicolon);
} else if (!strncmp(contents + tokens[i].off, "const", 5)) { /* constant */
+ do {
+ ++i;
+ g_expecttype(tokens[i++], TokenIdentifier);
+ if (tokens[i].type == TokenEqualSign) {
+ ++i;
+ i += g_expression(tokens + i, toksize - i);
+ }
+ } while (tokens[i].type == TokenComma);
+ g_expecttype(tokens[i], TokenSemicolon);
} else {
char buf[128];
snprintf(buf, tokens[i].len + 1, "%s", contents + tokens[i].off);
@@ -49,10 +92,13 @@ g_statement(Token *tokens, size_t toksize)
}
} else if (!strncmp(contents + tokens[i].off, "void", 4)) { /* expression */
} else if (tokens[i].type == TokenSemicolon) { /* noop */
+ ++i;
} else {
- errwarn("unexpected token \033[1m%s\033[0m, in place of a statement", 1,
- tokens[i], g_typetostr(tokens[i].type));
+ i += g_expression(tokens + i, toksize - i);
+ g_expecttype(tokens[i], TokenSemicolon);
}
+
+ return i;
}
size_t
@@ -60,24 +106,19 @@ g_function(Token *tokens, size_t toksize)
{
size_t i;
i = 0;
- fputs("identifier\n", stderr);
g_expecttype(tokens[i++], TokenIdentifier);
- fputs("parenthesis (opening)\n", stderr);
g_expecttype(tokens[i], TokenOpeningParenthesis);
- fputs("loop:\n", stderr);
if (tokens[i + 1].type == TokenKeyword
&& !strncmp(contents + tokens[i + 1].off, "void", 4))
i += 2;
else do {
++i;
- fputs("\tidentifier\n", stderr);
g_expecttype(tokens[i++], TokenIdentifier);
} while (tokens[i].type == TokenComma);
- fputs("parenthesis (closing)\n", stderr);
g_expecttype(tokens[i++], TokenClosingParenthesis);
- g_statement(tokens + i, toksize - i);
- ++i;
- return i;
+ i += g_statement(tokens + i, toksize - i);
+
+ return ++i;
}
size_t
@@ -87,4 +128,6 @@ g_main(Token *tokens, size_t toksize)
for (i = 0; i < toksize; ++i) {
i += g_function(tokens + i, toksize - i);
}
+
+ return i;
}
