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README.md

+To run the parser, run `make` then run `./SQLPParser`. An example of a test input is `select s.name from student s where s.name = "John";`. Currently a syntax error will be reported when the semi-colon is read, but the parse tree that is outputted is correct.
+
+The grammar is located in `SQLPGrammar.y`, and non-keyword types (such as `INTEGER`, `IDENTIFIER`, `STRING`) are defined in `SQLPScanner.l`. `util.c` contains the functions needed to build the con cell structure.
+
 A common way of defining the behavior of a process or thread in cases where
 performance is critical is in terms of a collection of n+1 files containing
 code in the C programming language: n "module" files with a ".c" suffix that

util.h

@@ -7,52 +7,31 @@
 #include <string.h>
 #include <assert.h>
 
-struct node {
-	int type;
-	int count;
-	struct node **children;
-};
-
-
-struct linked_node {
-	int type;
-	struct linked_node *next; // siblings
-	struct linked_node *children;
-};
-
 
+// Basic building blocks that contain char values
 typedef struct atom {
 	char* val;
 } atom;
 
-
+// A linked list like structure
 // car points to element the node is holding
 // cdr points to next cons cell in list or null
+// is_atom determines if car is an atom
 typedef struct cons_cell {
     void* car;
     struct cons_cell* cdr;
 	bool is_atom;
 } cons_cell;
 
-
-enum type {
-	SQLPProgram,
-	Identifier,
-	Query,
-	Select_Query, 
-	Body,
-	TablePath,
-	Union_Query,
-	Select_List,
-	AttrPath,
-	Operator,
-	Bool,
-	Pred
-};
-
+// Creates a cons_cell
 cons_cell* create_cons_cell(void* car, cons_cell* cdr);
+// Creates an atom
 atom* create_atom(char* val);
+// Creates a cons_cell that has an atom as its car
 cons_cell* create_cons_cell_w_atom(char* val, cons_cell* cdr);
+
+// The following are all helper functions to create the 
+// various relational algebra expressions
 cons_cell* create_spcol(cons_cell* var, cons_cell* pf);
 cons_cell* create_pf(cons_cell* attr, cons_cell* next_attr);
 cons_cell* create_table(char *table);
@@ -73,14 +52,8 @@ cons_cell* create_limit_operator(cons_cell* ra1, cons_cell* ra2);
 cons_cell* create_elim_operator(cons_cell* ra1, cons_cell* ra2);
 cons_cell* create_eval_operator(cons_cell* logic, cons_cell* cross);
 
-struct node *new_node(int count, int type);
-void translate(struct linked_node *linked_tree, struct node *tree);
-
+// Prints an in order traversal of the tree
 void print_cons_tree(cons_cell *root, int indent);
-void print_tree(struct node *root, int indent);
-void print_linked_tree(struct linked_node *root, int indent);
-void destroy_tree(struct node *root);
-bool match(struct linked_node *pat, struct linked_node *tree);
 #endif