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/* */
/* TOKENISER */
/* */
/******************************************************************************/
enum token_type {
TOK_NONE,
TOK_PAREN_OPEN, TOK_PAREN_CLOSE, TOK_NEWLINE, TOK_EOF,
TOK_PAREN_OPEN, TOK_PAREN_CLOSE, TOK_COMMA, TOK_NEWLINE, TOK_EOF,
TOK_FUN, TOK_END,
TOK_IDENT, TOK_LITERAL_INT
};
struct token {
enum token_type type;
char* str;
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next_ch();
skip_ws();
}
else if(ch == ')') {
add_token(TOK_PAREN_CLOSE, 0);
next_ch();
skip_ws();
}
else if(ch == ',') {
add_token(TOK_COMMA, 0);
next_ch();
skip_ws();
}
else if(ch == '\n' || ch == '\r') {
add_token(TOK_NEWLINE, 0);
next_ch();
/* collapse all versions, and multiples to a single token */
while(ch == '\n' || ch == '\r') next_ch();
skip_ws();
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enum node_type { NODE_ROOT, NODE_FUNDEF, NODE_FUNCALL, NODE_LITERAL_INT };
struct node {
struct node** childs;
int child_count;
char* name;
enum node_type type;
char* val;
};
struct node* node_new(enum node_type type) {
struct node* node = malloc(sizeof(struct node));
node->childs = 0;
node->child_count = 0;
node->name = 0;
node->type = type;
node->val = 0;
return node;
}
void node_add_child(struct node* parent, struct node* child) {
int new_size = sizeof(struct node*) * (++parent->child_count);
parent->childs = realloc(parent->childs, new_size);
parent->childs[parent->child_count-1] = child;
}
struct token* expect(enum token_type type) {
if(type == tokens[parse_pos].type) {
++parse_pos;
return &tokens[parse_pos-1];
}
else {
printf("expected (%d), got (%d)\n", type, tokens[parse_pos].type);
printf("expected (%d), got (%d), at (%d)\n",
type, tokens[parse_pos].type, parse_pos);
exit(-1);
}
}
int is_next_tok(enum token_type type) {
return tokens[parse_pos].type == type;
}
struct node* p_expr();
struct node* p_func_call() {
struct node* node = node_new(NODE_FUNCALL);
node->name = expect(TOK_IDENT)->str;
expect(TOK_PAREN_OPEN);
printf("1\n");
if(tokens[parse_pos].type != TOK_PAREN_CLOSE) {
printf("2\n");
node_add_child(node, p_expr());
printf("3\n");
while(tokens[parse_pos].type == TOK_COMMA) {
printf("4\n");
expect(TOK_LITERAL_INT);
expect(TOK_COMMA);
node_add_child(node, p_expr());
}
}
expect(TOK_PAREN_CLOSE);
return node;
}
struct node* p_statement() {
struct node* node;
struct node* p_var_use() {
/* todo: implement */
}
struct node* p_expr() {
switch(tokens[parse_pos].type) {
case TOK_IDENT:
if(tokens[parse_pos+1].type == TOK_PAREN_OPEN)
node = p_func_call();
expect(TOK_NEWLINE);
break;
return p_func_call();
else
return p_var_use();
case TOK_LITERAL_INT:
{
struct node* node = node_new(NODE_LITERAL_INT);
node->val = expect(TOK_LITERAL_INT)->str;
return node;
}
default:
printf("can't parse statement, (%d)\n", tokens[parse_pos].type);
printf("can't parse expression, (%d)\n", tokens[parse_pos].type);
exit(-1);
}
}
struct node* p_statement() {
printf("p_statement\n");
struct node* node;
switch(tokens[parse_pos].type) {
default:
node = p_expr();
expect(TOK_NEWLINE);
}
return node;
}
struct node* p_fun() {
printf("p_fun\n");
struct node* node = node_new(NODE_FUNDEF);
expect(TOK_FUN);
node->name = expect(TOK_IDENT)->str;
expect(TOK_PAREN_OPEN);
expect(TOK_PAREN_CLOSE);
expect(TOK_NEWLINE);
while(!is_next_tok(TOK_END)) {
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}
printf("}\n");
break;
case NODE_FUNCALL:
print_indent(indent);
printf("%s(\n", node->name);
for(int j = 0; j < node->child_count; ++j) {
print_tree(node->childs[j], indent);
if(j < node->child_count) printf(",\n");
print_tree(node->childs[j], indent+1);
if(j < node->child_count-1)
printf(",\n");
else
printf("\n");
}
print_indent(indent);
printf(")");
break;
case NODE_LITERAL_INT:
print_indent(indent);
printf("%s", node->val);
break;
default:
printf("(UNKNOWN TOKEN)");
}
}
int main() {
tokenise();
print_tokens();
struct node* node = parse();
print_tree(node, 0);
return 0;
}
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