common: First pass at IdStringList methods

Signed-off-by: D. Shah <dave@ds0.me>

common/nextpnr.cc

@@ -69,6 +69,41 @@ void IdString::initialize_add(const BaseCtx *ctx, const char *s, int idx)
     ctx->idstring_idx_to_str->push_back(&insert_rc.first->first);
 }
 
+IdStringList IdStringList::parse(Context *ctx, const std::string &str)
+{
+    char delim = ctx->getNameDelimiter();
+    size_t id_count = std::count(str.begin(), str.end(), delim) + 1;
+    IdStringList list(id_count);
+    size_t start = 0;
+    for (size_t i = 0; i < id_count; i++) {
+        size_t end = str.find(delim, start);
+        NPNR_ASSERT((i == (id_count - 1)) || (end != std::string::npos));
+        list.ids[i] = ctx->id(str.substr(start, end - start));
+        start = end + 1;
+    }
+    return list;
+}
+
+void IdStringList::build_str(const Context *ctx, std::string &str) const
+{
+    char delim = ctx->getNameDelimiter();
+    bool first = true;
+    str.clear();
+    for (auto entry : ids) {
+        if (!first)
+            str += delim;
+        str += entry.str(ctx);
+        first = false;
+    }
+}
+
+std::string IdStringList::str(const Context *ctx) const
+{
+    std::string s;
+    build_str(ctx, s);
+    return s;
+}
+
 TimingConstrObjectId BaseCtx::timingWildcardObject()
 {
     TimingConstrObjectId id;

common/nextpnr.h

@@ -156,7 +156,7 @@ template <typename T, size_t N> class SSOArray
     size_t m_size;
 
   private:
-    inline bool is_heap() { return (m_size > N); }
+    inline bool is_heap() const { return (m_size > N); }
     void alloc()
     {
         if (is_heap()) {
@@ -165,8 +165,8 @@ template <typename T, size_t N> class SSOArray
     }
 
   public:
-    T *data() { return is_heap() ? data_heap : &data_static; }
+    T *data() { return is_heap() ? data_heap : data_static; }
-    const T *data() const { return is_heap() ? data_heap : &data_static; }
+    const T *data() const { return is_heap() ? data_heap : data_static; }
     size_t size() const { return m_size; }
 
     T *begin() { return data(); }
@@ -174,6 +174,8 @@ template <typename T, size_t N> class SSOArray
     const T *begin() const { return data(); }
     const T *end() const { return data() + m_size; }
 
+    SSOArray() : m_size(0){};
+
     SSOArray(size_t size, const T &init = T()) : m_size(size)
     {
         alloc();
@@ -205,11 +207,35 @@ template <typename T, size_t N> class SSOArray
             return true;
         return !std::equal(begin(), end(), other.begin());
     }
+    T &operator[](size_t idx)
+    {
+        NPNR_ASSERT(idx < m_size);
+        return data()[idx];
+    }
+    const T &operator[](size_t idx) const
+    {
+        NPNR_ASSERT(idx < m_size);
+        return data()[idx];
+    }
 };
 
 struct IdStringList
 {
     SSOArray<IdString, 4> ids;
+
+    IdStringList(){};
+    explicit IdStringList(size_t n) : ids(n, IdString()){};
+    explicit IdStringList(IdString id) : ids(1, id){};
+    template <typename Tlist> IdStringList(const Tlist &list) : ids(list){};
+
+    static IdStringList parse(Context *ctx, const std::string &str);
+    void build_str(const Context *ctx, std::string &str) const;
+    std::string str(const Context *ctx) const;
+
+    size_t size() const { return ids.size(); }
+    const IdString *begin() const { return ids.begin(); }
+    const IdString *end() const { return ids.end(); }
+    const IdString &operator[](size_t idx) const { return ids[idx]; }
 };
 
 struct GraphicElement