Updated structure

tests/sprint2/other/calc.h

@@ -0,0 +1,48 @@
+/* Function type. */
+typedef double (func_t) (double);
+/* Data type for links in the chain of symbols. */
+struct symrec
+{
+  char *name;  /* name of symbol */
+  int type;    /* type of symbol: either VAR or FUN */
+  union
+  {
+    double var;    /* value of a VAR */
+    func_t *fun;   /* value of a FUN */
+  } value;
+  struct symrec *next;  /* link field */
+};
+typedef struct symrec symrec;
+
+/* The symbol table: a chain of 'struct symrec'. */
+extern symrec *sym_table;
+
+symrec *putsym (char const *name, int sym_type);
+symrec *getsym (char const *name);
+struct init
+{
+  char const *name;
+  func_t *fun;
+};
+struct init const funs[] =
+{
+  { "atan", atan },
+  { "cos",  cos  },
+  { "exp",  exp  },
+  { "ln",   log  },
+  { "sin",  sin  },
+  { "sqrt", sqrt },
+  { 0, 0 },
+};
+/* The symbol table: a chain of 'struct symrec'. */
+symrec *sym_table;
+/* Put functions in table. */
+static void
+init_table (void)
+{
+  for (int i = 0; funs[i].name; i++)
+    {
+      symrec *ptr = putsym (funs[i].name, FUN);
+      ptr->value.fun = funs[i].fun;
+    }
+}