renamed prog to begin and added basics for the manual

src/parse.cpp

@@ -161,21 +161,25 @@ namespace Parser {
 
         // okay so the first letter was not actually closing the string...
         int string_length = 0;
-        while (text[*index_in_text+string_length] != '"' ||
-               text[*index_in_text+string_length] == '\\')
+        bool escaping = false;
+        while (!(text[*index_in_text+string_length] == '"' && !escaping))
         {
+            if (escaping)
+                escaping = false;
+            else
+                if (text[*index_in_text+string_length] == '\\')
+                    escaping = true;
+
             ++string_length;
         }
 
         // we found the end of the string
         text[*index_in_text+string_length] = '\0';
 
-        if (!unescape_string(text+(*index_in_text))) {
-            create_parsing_error(
-                "The string '%s' at %s:%d:%d could not be unescaped.",
-                text+(*index_in_text), parser_file, parser_line, parser_col);
-            return nullptr;
-        }
+        // NOTE(Felix): Tactic: Through unescaping the string will
+        // only get shorter, so we replace it inplace and later jump
+        // to the original end of the string.
+        try unescape_string(text+(*index_in_text));
 
         String* string = Memory::create_string("", string_length);
 
@@ -415,9 +419,9 @@ namespace Parser {
                 }
 
                 // we are now in the function body, just wrap it in an
-                // implicit prog
+                // implicit begin
                 try macro->value.function.body = Memory::create_lisp_object_pair(
-                    Memory::get_or_create_lisp_object_symbol("prog"),
+                    Memory::get_or_create_lisp_object_symbol("begin"),
                     body);
 
                 // macro->value.function = function;