node: implement switch, break, continue (basic)

fixtures/0014-switch.php

@@ -0,0 +1,16 @@
+<?php
+
+$x = true;
+switch($x) {
+	case true:
+		echo "true";
+		break;
+		echo "unreached";
+	
+	case false:
+		echo "false";
+		// fallthrough
+		
+	default:
+		echo "default";
+}

node.go

@@ -845,6 +845,69 @@ func (this *conversionState) convertNoFreeFloating(n_ node.Node) (string, error)
 
 		return ret, nil
 
+	case *stmt.Switch:
+		cond, err := this.convert(n.Cond)
+		if err != nil {
+			return "", parseErr{n, err}
+		}
+
+		cases := make([]string, 0, len(n.CaseList.Cases))
+		for _, ncase := range n.CaseList.Cases {
+			switch ncase.(type) {
+			case *stmt.Default, *stmt.Case:
+				caseStr, err := this.convert(ncase)
+				if err != nil {
+					return "", parseErr{n, err}
+				}
+				cases = append(cases, caseStr)
+
+			default:
+				return "", parseErr{ncase, fmt.Errorf("expected Case/Default")}
+			}
+		}
+
+		// TODO use dead code elimination after `break` to clean up redundant fallthrough statements
+		return "switch " + cond + " {\n" + strings.Join(cases, "\n") + "}\n", nil
+
+	case *stmt.Case:
+		// Add a `fallthrough` to the end
+		// TODO then use dead code elimination to clean them up
+		stmtBody, err := this.convert(stmt.NewStmtList(n.Stmts))
+		if err != nil {
+			return "", parseErr{n, err}
+		}
+
+		cond, err := this.convert(n.Cond)
+		if err != nil {
+			return "", parseErr{n, err}
+		}
+
+		return "case " + cond + ":\n" + stmtBody + "\nfallthrough\n", nil
+
+	case *stmt.Default:
+		// Add a `fallthrough` to the end
+		// TODO then use dead code elimination to clean them up
+		stmtBody, err := this.convert(stmt.NewStmtList(n.Stmts))
+		if err != nil {
+			return "", parseErr{n, err}
+		}
+
+		return "default: " + stmtBody + "\nfallthrough\n", nil
+
+	case *stmt.Break:
+		if n.Expr != nil {
+			return "", parseErr{n, fmt.Errorf("break {expr} is not yet supported")} // TODO implement numbered break
+		}
+
+		return "break\n", nil
+
+	case *stmt.Continue:
+		if n.Expr != nil {
+			return "", parseErr{n, fmt.Errorf("continue {expr} is not yet supported")} // TODO implement numbered continue
+		}
+
+		return "continue\n", nil
+
 	case *stmt.Try:
 
 		// Generate an if err != nil {} block that we can bring up whenever