began working on state machine for parse_input()

parse-input.cc

@@ -1,6 +1,51 @@
 
 #include <iostream>
+#include <stdio.h>
+#include <ctype.h>  /* isspace() */
+#include "parse-input.h"
+using namespace std;
+
+#define SET_ERROR(err, args...) \
+    sprintf(errstr, err " at line %d, column %d", ##args, lineno, colno)
 
 void parse_input(refptr< vector<unichar_t> > ucs)
 {
+    enum State { INITIAL, LB, SECTION_NAME, RB };
+    State state = INITIAL;
+    int lineno = 1;
+    int colno = 1;
+    bool error = false;
+    char errstr[200];
+
+    for (int i = 0, sz = ucs->size(); i < sz; i++)
+    {
+        unichar_t c = (*ucs)[i];
+        if (c == '\n')
+        {
+            lineno++;
+            colno = 1;
+        }
+        else
+        {
+            colno++;
+        }
+        switch (state)
+        {
+            case INITIAL:
+                if (c == '[')
+                {
+                    state = LB;
+                }
+                else if (isspace(c))
+                {
+                }
+                else
+                {
+                    error = true;
+                    SET_ERROR("Unexpected character 0x%x (%c) in input file",
+                            c, c);
+                }
+                break;
+        }
+    }
 }