step: deal with parenthesis
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015ee9595f
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495418dadc
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src/mumble.c
20
src/mumble.c
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@ -23,6 +23,11 @@ long evaluate_operation(char* op, long x, long y)
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return 0;
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}
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int is_ignorable(mpc_ast_t* t){
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int is_regex = !strcmp(t->tag, "regex");
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int is_parenthesis = !strcmp(t->tag, "char") && !strcmp(t->contents, "(");
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return is_regex || is_parenthesis;
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}
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long evaluate_ast(mpc_ast_t* t)
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{
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// Base case #1: It's a number
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@ -41,24 +46,25 @@ long evaluate_ast(mpc_ast_t* t)
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printf("\nCase #2, %s", t->children[0]->contents);
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return atoi(t->children[0]->contents);
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}
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// Case #3: Parenthesis case
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if (t->children_num == 2 && !strcmp(t->children[0]->tag, "expr|>") && strstr(t->children[1]->tag, "regex")) {
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return evaluate_ast(t->children[0]);
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// Base case #3: Top level parenthesis
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if (t->children_num == 2 && strstr(t->children[0]->tag, "expr|>") && !strcmp(t->children[1]->tag, "regex")) {
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if (VERBOSE)
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printf("\nCase #3, top level parenthesis");
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return evaluate_ast(t->children[0]);
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}
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// Case #4: Unary operations case
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// Case #4: Unary operations case
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// Case #5: Binary (or more) operations case
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long x;
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char* operation;
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if (t->children_num > 3 && !strcmp(t->children[0]->tag, "regex") && strstr(t->children[1]->tag, "operator")) {
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if (t->children_num > 3 && is_ignorable(t->children[0]) && strstr(t->children[1]->tag, "operator")) {
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operation = t->children[1]->contents;
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if (VERBOSE)
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printf("\nCase #5, %s", operation);
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x = evaluate_ast(t->children[2]);
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int i = 3;
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while ((i < t->children_num) && strstr(t->children[i]->tag, "expr")) {
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// note that when reaching a closing parenthesis, ^ returns false
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long y = evaluate_ast(t->children[i]);
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x = evaluate_operation(operation, x, y);
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i++;
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