Start refactoring the YAML printer

I was never really happy with the sqltoaster::printer_t struct and the
use of iomanips to control indentation levels and list construction. So,
I'm going to rewrite the YAML printing to instead use a stack push/pop
system of generic YAML node elements.

The first step to this is to get rid of storing the output format in an
iomanip xalloc bucket, which was just sill to begin with.

Issue #104

Author: jaypipes

sqltoaster/main.cc

@@ -63,7 +63,7 @@ int main (int argc, char *argv[])
     auto dur = measure<std::chrono::nanoseconds>::execution(p);
     sqltoaster::printer ptr(p.res, std::cout);
     if (use_yaml)
-        ptr.set_yaml(std::cout);
+        ptr.output_format = sqltoaster::OUTPUT_FORMAT_YAML;
     if (p.res.code == sqltoast::PARSE_OK)
         std::cout << ptr << std::endl;
     else if (p.res.code == sqltoast::PARSE_INPUT_ERROR)

sqltoaster/printer.cc

@@ -10,7 +10,7 @@
 namespace sqltoaster {
 
 std::ostream& operator<< (std::ostream& out, printer_t& ptr) {
-    if (! ptr.use_yaml(out)) {
+    if (ptr.output_format == OUTPUT_FORMAT_DEFAULT) {
         unsigned int x = 0;
         for (auto stmt_ptr_it = ptr.res.statements.cbegin();
                 stmt_ptr_it != ptr.res.statements.cend();

sqltoaster/printer.h

@@ -14,37 +14,35 @@
 
 namespace sqltoaster {
 
+typedef enum output_format {
+    OUTPUT_FORMAT_DEFAULT,
+    OUTPUT_FORMAT_YAML
+} output_format_t;
+
 const long LIST_ITEM_OFF = 0;
 const long LIST_ITEM_ON = 1;
 
-const long OUTPUT_FORMAT_DEFAULT = 1;
-const long OUTPUT_FORMAT_YAML = 2;
-
-const int OUTPUT_FORMAT_XALLOC_INDEX = 0;
-const int INDENT_LEVEL_XALLOC_INDEX = 1;
+const int INDENT_LEVEL_XALLOC_INDEX = 0;
 // Informs the printer whether the current item to be printed is a list item
-const int LIST_ITEM_XALLOC_INDEX = 2;
+const int LIST_ITEM_XALLOC_INDEX = 1;
 
 typedef struct printer {
-    int iomanip_indexes[3];
+    int iomanip_indexes[2];
     sqltoast::parse_result_t& res;
-    printer(sqltoast::parse_result_t& res, std::ostream& out) : res(res)
+    output_format_t output_format;
+    printer(
+            sqltoast::parse_result_t& res,
+            std::ostream& out) :
+        res(res),
+        output_format(OUTPUT_FORMAT_DEFAULT)
     {
-        iomanip_indexes[OUTPUT_FORMAT_XALLOC_INDEX] = std::ios_base::xalloc();
         iomanip_indexes[INDENT_LEVEL_XALLOC_INDEX] = std::ios_base::xalloc();
         iomanip_indexes[LIST_ITEM_XALLOC_INDEX] = std::ios_base::xalloc();
         int idx_indent = iomanip_indexes[INDENT_LEVEL_XALLOC_INDEX];
         out.iword(idx_indent) = 0;
         int idx_list_item = iomanip_indexes[LIST_ITEM_XALLOC_INDEX];
         out.iword(idx_list_item) = LIST_ITEM_OFF;
     }
-    inline void set_yaml(std::ostream& out) {
-        int idx_format = iomanip_indexes[OUTPUT_FORMAT_XALLOC_INDEX];
-        out.iword(idx_format) = OUTPUT_FORMAT_YAML;
-    }
-    inline bool use_yaml(std::ostream& out) const {
-        return (out.iword(iomanip_indexes[OUTPUT_FORMAT_XALLOC_INDEX]) == OUTPUT_FORMAT_YAML);
-    }
     inline void indent_push(std::ostream& out) {
         int idx_indent = iomanip_indexes[INDENT_LEVEL_XALLOC_INDEX];
         long cur_indent = out.iword(idx_indent);