Convert many loops to range-for or std algorithms. NFC.

Also add comments about indexing and when we don't use range-for.

Author: rpavlik

src/bsp.cpp

@@ -12,13 +12,8 @@ SBsp2 *SBsp2::Alloc() { return (SBsp2 *)AllocTemporary(sizeof(SBsp2)); }
 SBsp3 *SBsp3::Alloc() { return (SBsp3 *)AllocTemporary(sizeof(SBsp3)); }
 
 SBsp3 *SBsp3::FromMesh(const SMesh *m) {
-    SBsp3 *bsp3 = NULL;
-    int i;
-
     SMesh mc = {};
-    for(i = 0; i < m->l.n; i++) {
-        mc.AddTriangle(&(m->l.elem[i]));
-    }
+    for(auto const &elt : m->l) { mc.AddTriangle(&elt); }
 
     srand(0); // Let's be deterministic, at least!
     int n = mc.l.n;
@@ -28,10 +23,8 @@ SBsp3 *SBsp3::FromMesh(const SMesh *m) {
         swap(mc.l.elem[k], mc.l.elem[n]);
     }
 
-    for(i = 0; i < mc.l.n; i++) {
-        bsp3 = InsertOrCreate(bsp3, &(mc.l.elem[i]), NULL);
-    }
-
+    SBsp3 *bsp3 = NULL;
+    for(auto &elt : mc.l) { bsp3 = InsertOrCreate(bsp3, &elt, NULL); }
     mc.Clear();
     return bsp3;
 }

src/constraint.cpp

@@ -59,8 +59,8 @@ std::string Constraint::DescriptionString() const {
 void Constraint::DeleteAllConstraintsFor(Constraint::Type type, hEntity entityA, hEntity ptA)
 {
     SK.constraint.ClearTags();
-    for(int i = 0; i < SK.constraint.n; i++) {
-        ConstraintBase *ct = &(SK.constraint.elem[i]);
+    for(auto &constraint : SK.constraint) {
+        ConstraintBase *ct = &constraint;
         if(ct->type != type) continue;
 
         if(ct->entityA != entityA) continue;

src/dsc.h

@@ -434,10 +434,7 @@ class IdList {
     }
 
     void ClearTags() {
-        int i;
-        for(i = 0; i < n; i++) {
-            elem[i].tag = 0;
-        }
+        for(auto &elt : *this) { elt.tag = 0; }
     }
 
     void Tag(H h, int tag) {

src/entity.cpp

@@ -922,19 +922,16 @@ void EntityBase::GenerateEquations(IdList<Equation,hEquation> *l) const {
             // If the two endpoints of the arc are constrained coincident
             // (to make a complete circle), then our distance constraint
             // would be redundant and therefore overconstrain things.
-            int i;
-            for(i = 0; i < SK.constraint.n; i++) {
-                ConstraintBase *c = &(SK.constraint.elem[i]);
-                if(c->group != group) continue;
-                if(c->type != Constraint::Type::POINTS_COINCIDENT) continue;
-
-                if((c->ptA == point[1] && c->ptB == point[2]) ||
-                   (c->ptA == point[2] && c->ptB == point[1]))
-                {
-                    break;
-                }
+            auto it = std::find_if(SK.constraint.begin(), SK.constraint.end(),
+                                   [&](ConstraintBase const &con) {
+                                       return (con.group == group) &&
+                                              (con.type == Constraint::Type::POINTS_COINCIDENT) &&
+                                              ((con.ptA == point[1] && con.ptB == point[2]) ||
+                                               (con.ptA == point[2] && con.ptB == point[1]));
+                                   });
+            if(it != SK.constraint.end()) {
+                break;
             }
-            if(i < SK.constraint.n) break;
 
             Expr *ra = Constraint::Distance(workplane, point[0], point[1]);
             Expr *rb = Constraint::Distance(workplane, point[0], point[2]);

src/export.cpp

@@ -96,9 +96,8 @@ void SolveSpaceUI::ExportSectionTo(const Platform::Path &filename) {
     bl.CullIdenticalBeziers(/*both=*/true);
 
     // Collect lines and beziers with custom style & export.
-    int i;
-    for(i = 0; i < SK.entity.n; i++) {
-        Entity *e = &(SK.entity.elem[i]);
+    for(auto &ent : SK.entity) {
+        Entity *e = &ent;
         if (!e->IsVisible()) continue;
         if (e->style.v < Style::FIRST_CUSTOM) continue;
         if (!Style::Exportable(e->style.v)) continue;
@@ -186,7 +185,6 @@ class GetEdgesCanvas : public Canvas {
 };
 
 void SolveSpaceUI::ExportViewOrWireframeTo(const Platform::Path &filename, bool exportWireframe) {
-    int i;
     SEdgeList edges = {};
     SBezierList beziers = {};
 
@@ -206,8 +204,8 @@ void SolveSpaceUI::ExportViewOrWireframeTo(const Platform::Path &filename, bool
         sm = NULL;
     }
 
-    for(i = 0; i < SK.entity.n; i++) {
-        Entity *e = &(SK.entity.elem[i]);
+    for(auto &entity : SK.entity) {
+        Entity *e = &entity;
         if(!e->IsVisible()) continue;
         if(e->construction) continue;
 

src/exportvector.cpp

@@ -1027,8 +1027,9 @@ void SvgFileWriter::StartFile() {
     double sw = max(ptMax.x - ptMin.x, ptMax.y - ptMin.y) / 1000;
     fprintf(f, "stroke-width:%f;\r\n", sw);
     fprintf(f, "}\r\n");
-    for(int i = 0; i < SK.style.n; i++) {
-        Style *s = &SK.style.elem[i];
+    for(auto &style : SK.style) {
+        Style *s = &style;
+
         RgbaColor strokeRgb = Style::Color(s->h, /*forExport=*/true);
         StipplePattern pattern = Style::PatternType(s->h);
         double stippleScale = Style::StippleScaleMm(s->h);

src/file.cpp

@@ -20,8 +20,8 @@ void SolveSpaceUI::ClearExisting() {
     UndoClearStack(&redo);
     UndoClearStack(&undo);
 
-    for(int i = 0; i < SK.groupOrder.n; i++) {
-        Group *g = SK.GetGroup(SK.groupOrder.elem[i]);
+    for(hGroup hg : SK.groupOrder) {
+        Group *g = SK.GetGroup(hg);
         g->Clear();
     }
 
@@ -301,39 +301,39 @@ bool SolveSpaceUI::SaveToFile(const Platform::Path &filename) {
     fprintf(fh, "%s\n\n\n", VERSION_STRING);
 
     int i, j;
-    for(i = 0; i < SK.group.n; i++) {
-        sv.g = SK.group.elem[i];
+    for(auto &g : SK.group) {
+        sv.g = g;
         SaveUsingTable(filename, 'g');
         fprintf(fh, "AddGroup\n\n");
     }
 
-    for(i = 0; i < SK.param.n; i++) {
-        sv.p = SK.param.elem[i];
+    for(auto &p : SK.param) {
+        sv.p = p;
         SaveUsingTable(filename, 'p');
         fprintf(fh, "AddParam\n\n");
     }
 
-    for(i = 0; i < SK.request.n; i++) {
-        sv.r = SK.request.elem[i];
+    for(auto &r : SK.request) {
+        sv.r = r;
         SaveUsingTable(filename, 'r');
         fprintf(fh, "AddRequest\n\n");
     }
 
-    for(i = 0; i < SK.entity.n; i++) {
-        (SK.entity.elem[i]).CalculateNumerical(/*forExport=*/true);
-        sv.e = SK.entity.elem[i];
+    for(auto &e : SK.entity) {
+        e.CalculateNumerical(/*forExport=*/true);
+        sv.e = e;
         SaveUsingTable(filename, 'e');
         fprintf(fh, "AddEntity\n\n");
     }
 
-    for(i = 0; i < SK.constraint.n; i++) {
-        sv.c = SK.constraint.elem[i];
+    for(auto &c : SK.constraint) {
+        sv.c = c;
         SaveUsingTable(filename, 'c');
         fprintf(fh, "AddConstraint\n\n");
     }
 
-    for(i = 0; i < SK.style.n; i++) {
-        sv.s = SK.style.elem[i];
+    for(auto &s : SK.style) {
+        sv.s = s;
         if(sv.s.h.v >= Style::FIRST_CUSTOM) {
             SaveUsingTable(filename, 's');
             fprintf(fh, "AddStyle\n\n");