1 files changed, 85 insertions, 0 deletions
diff --git a/src/parse_expr.yy b/src/parse_expr.yy
new file mode 100644
index 0000000..c2943c2
--- /dev/null
+++ b/src/parse_expr.yy
@@ -0,0 +1,85 @@
+%{
+#include "chill_run_util.hh"
+#include "parse_expr.ll.hh"
+
+extern int yydebug;
+
+void yyerror(const char*);
+int yyparse(simap_vec_t** rel);
+
+static simap_vec_t* return_rel; // used as the return value for yyparse
+
+%}
+
+%union {
+  int val;
+  char* str_val;
+  simap_t* cond_item;
+  simap_vec_t* cond;
+}
+
+%token <val> NUMBER
+%token <val> LEVEL
+%token <str_val> VARIABLE
+
+%left LE GE EQ '<' '>'
+%left '-' '+' '*' '/'
+
+/*the final output from this language should be an Omega Relation object*/
+%type <cond> cond prog
+%type <cond_item> expr add_expr mul_expr neg_expr
+
+%%
+prog : cond                      { return_rel = make_prog($1); }
+;
+
+cond : expr '>' expr             { $$ = make_cond_gt($1, $3); }
+     | expr '<' expr             { $$ = make_cond_lt($1, $3); }
+     | expr GE expr              { $$ = make_cond_ge($1, $3); }
+     | expr LE expr              { $$ = make_cond_le($1, $3); }
+     | expr EQ expr              { $$ = make_cond_eq($1, $3); }
+;
+
+expr : add_expr                  { $$ = $1; }
+;
+
+add_expr : add_expr '+' mul_expr { $$ = make_cond_item_add($1,$3); }
+         | add_expr '-' mul_expr { $$ = make_cond_item_sub($1,$3); }
+         | mul_expr              { $$ = $1; }
+;
+
+mul_expr : mul_expr '*' neg_expr { $$ = make_cond_item_mul($1,$3); }
+         | neg_expr              { $$ = $1; }
+;
+
+neg_expr : '-' neg_expr          { $$ = make_cond_item_neg($2); }
+         | '(' expr ')'          { $$ = $2; }
+         | NUMBER                { $$ = make_cond_item_number($1); }
+         | LEVEL                 { $$ = make_cond_item_level($1); }
+         | VARIABLE              { $$ = make_cond_item_variable($1); }
+;
+%%
+
+void yyerror(const char* msg) {
+  fprintf(stderr, "Parse error: %s", msg);
+}
+
+simap_vec_t* parse_relation_vector(const char* expr) {
+  yydebug=0;
+  YY_BUFFER_STATE state;
+  
+  //if(yylex_init()) {
+  //   TODO: error out or something
+  //}
+  
+  state = yy_scan_string(expr);
+  
+  if(yyparse()) {
+    // TODO: error out or something
+  }
+  
+  yy_delete_buffer(state);
+  yylex_destroy();
+  return return_rel;
+}
+