diff --git a/grammar/hxml.bnf b/grammar/hxml.bnf
index 157899236..a044940cc 100644
--- a/grammar/hxml.bnf
+++ b/grammar/hxml.bnf
@@ -31,8 +31,16 @@ private line_recovery ::= !(eol_)
 private option_ ::= (lib | define | classpath | main | property | COMMENT)
 
 property ::= option value? {pin=1}
-define ::= '-D' value {pin=1}
-lib ::= '-lib' value (':' value)? {pin=1}
-classpath ::= '-cp' value {pin=1}
-main ::= '-main' qualifiedName {pin=1}
+define ::= ('-D'|'--define') value {pin=1}
 
+lib ::= (libHx3|libHx4) value (':' value)? {pin=1}
+private libHx3 ::= '-lib'
+private libHx4 ::= '-L'|'--library'
+
+classpath ::= (classpathHx3|classpathHx4) value {pin=1}
+private classpathHx3 ::= '-cp'
+private classpathHx4 ::= '-p'
+
+main ::= (mainHx3| mainHx4) qualifiedName {pin=1}
+private mainHx3 ::= '-main'
+private mainHx4 ::= '-m'| '--main'
diff --git a/src/META-INF/plugin.xml b/src/META-INF/plugin.xml
index 0fc2a3536..22eda0a38 100644
--- a/src/META-INF/plugin.xml
+++ b/src/META-INF/plugin.xml
@@ -85,6 +85,8 @@
   <![CDATA[
       <p>Unreleased changes</p>
       <ul>
+        <li>Add HXML completion for Haxe 4</li>
+        <li>Fixed issue where IDE would freeze when writing HXML files</li>
         <li>Add HashLink target</li>
         <li>improved block-statement parsing and added quickfix for missing semicolon</li>
         <li>Add support for import.hx</li>
diff --git a/src/common/com/intellij/plugins/haxe/haxelib/HaxelibCommandUtils.java b/src/common/com/intellij/plugins/haxe/haxelib/HaxelibCommandUtils.java
index 3c7c301ef..da78a2058 100644
--- a/src/common/com/intellij/plugins/haxe/haxelib/HaxelibCommandUtils.java
+++ b/src/common/com/intellij/plugins/haxe/haxelib/HaxelibCommandUtils.java
@@ -39,6 +39,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Scanner;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Utilities to run the haxelib command and capture its output.
@@ -180,86 +181,30 @@ public static List<String> getProcessStdout(@NotNull ArrayList<String> commandLi
       Process process = builder.start();
       InputStreamReader reader = new InputStreamReader(process.getInputStream());
       Scanner scanner = new Scanner(reader);
+      process.waitFor(100, TimeUnit.MILLISECONDS);
 
-      while (scanner.hasNextLine()) {
-        String nextLine = scanner.nextLine();
-        strings.add(nextLine);
+      if(reader.ready()) {
+        while (scanner.hasNextLine()) {
+          String nextLine = scanner.nextLine();
+          strings.add(nextLine);
+        }
       }
-      process.waitFor();
 
-      /*
-      try {
-        Thread.sleep(250);
-        try {
-          process.exitValue();
-        }
-        catch (IllegalThreadStateException e) {
+      if(process.isAlive()) {
+        if(!process.waitFor(10, TimeUnit.MILLISECONDS)) {
           process.destroy();
         }
       }
-      catch (InterruptedException e) {
-        e.printStackTrace();
-      }
-      */
-    }
-    catch (IOException e) {
-      e.printStackTrace();
-    }
-    catch (InterruptedException e) {
-      e.printStackTrace();
-    }
-
-    return strings;
-  }
-
-
-  //private static Logger log = Logger.getInstance(HaxelibCommandUtils.class);
-
-  public static List<String> getProcessStderr(ArrayList<String> commandLineArguments, File dir, @Nullable HaxeSdkAdditionalDataBase haxeSdkData) {
-    List<String> strings = new ArrayList<String>();
-
-    try {
-      ProcessBuilder builder = HaxeSdkUtilBase.createProcessBuilder(commandLineArguments, dir, haxeSdkData);
-      Process process = builder.start();
-      InputStreamReader reader = new InputStreamReader(process.getErrorStream());
-      Scanner scanner = new Scanner(reader);
-
-      while (scanner.hasNextLine()) {
-        String nextLine = scanner.nextLine();
-        strings.add(nextLine);
-      }
 
-      //log.error(StringUtil.join(strings, "\n"));
-      process.waitFor();
 
-      /*
-      try {
-        Thread.sleep(250);
-        try {
-          process.exitValue();
-        }
-        catch (IllegalThreadStateException e) {
-          process.destroy();
-        }
-      }
-      catch (InterruptedException e) {
-        e.printStackTrace();
-      }
-      */
-    }
-    catch (IOException e) {
-      e.printStackTrace();
-      //log.error(StringUtil.getMessage(e));
     }
-    catch (InterruptedException e) {
+    catch (IOException | InterruptedException e) {
       e.printStackTrace();
-      //log.error(StringUtil.getMessage(e));
     }
 
     return strings;
   }
 
-
   /**
    * Run a shell command in the (IDEA's) current directory, capturing its standard output.
    *
@@ -271,8 +216,4 @@ public static List<String> getProcessStdout(@NotNull ArrayList<String> commandLi
     return getProcessStdout(commandLineArguments, null, haxeSdkData);
   }
 
-  public static List<String> getProcessStderr(ArrayList<String> commandLineArguments, @Nullable HaxeSdkAdditionalDataBase haxeSdkData) {
-    return getProcessStderr(commandLineArguments, null, haxeSdkData);
-  }
-
 }
diff --git a/src/common/com/intellij/plugins/haxe/ide/HXMLCompilerArgumentsCompletionContributor.java b/src/common/com/intellij/plugins/haxe/ide/HXMLCompilerArgumentsCompletionContributor.java
index c4786d7d6..0d027b3cc 100644
--- a/src/common/com/intellij/plugins/haxe/ide/HXMLCompilerArgumentsCompletionContributor.java
+++ b/src/common/com/intellij/plugins/haxe/ide/HXMLCompilerArgumentsCompletionContributor.java
@@ -33,6 +33,7 @@
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.StringJoiner;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -41,54 +42,99 @@
  */
 public class HXMLCompilerArgumentsCompletionContributor extends CompletionContributor {
 
-  public static List<HXMLCompletionItem> COMPILER_ARGUMENTS = null;
-  public static List<HXMLCompletionItem> COMPILER_ARGUMENTS2 = null;
-  public static final Pattern PATTERN = Pattern.compile("-([a-z-_0-9]+)[\\s](<[^>]+>)?[^:]+:[\\t\\s]+([^\\r\\n]+)");
-  public static final Pattern PATTERN2 = Pattern.compile("--([a-z-_0-9]+)[^:]+:[\\t\\s]+([^\\r\\n]+)");
+  public static List<HXMLCompletionItem> COMPILER_ARGUMENTS =  new ArrayList<>();;
+  public static List<HXMLCompletionItem> COMPILER_ARGUMENTS2 =  new ArrayList<>();;
+  public static final Pattern HAXE3_PATTERN = Pattern.compile("-([a-z-_0-9]+)[\\s](<[^>]+>)?[^:]+:[\\t\\s]+([^\\r\\n]+)");
+  public static final Pattern HAXE3_PATTERN2 = Pattern.compile("--([a-z-_0-9]+)[^:]+:[\\t\\s]+([^\\r\\n]+)");
+
+  public static final Pattern HAXE4_PATTERN = Pattern.compile("(-((?<short>([a-z_0-9]+)),\\s))?--(?<long>[a-z-_0-9]+)[\\s](?<param><[^>]+>)?\\s*(?<param2>\\[.*\\])?\\s+[\\t\\s]+(?<description>[^\\r\\n]+)", Pattern.CASE_INSENSITIVE);
 
   private void getCompilerArguments() {
-    List<HXMLCompletionItem> compilerArguments = new ArrayList<HXMLCompletionItem>();
-    List<HXMLCompletionItem> compilerArguments2 = new ArrayList<HXMLCompletionItem>();
-    ArrayList<String> commandLine = new ArrayList<String>();
+    ArrayList<String> commandLine = new ArrayList<>();
     List<String> strings = getStrings(commandLine);
 
-    Matcher matcher;
+    addHaxe4CompilerArguments(strings);
+    addHaxe3CompilerArguments(strings);
+  }
+
+  private void addHaxe3CompilerArguments(List<String> strings) {
     for (int i = 0; i < strings.size(); i++) {
       String text = strings.get(i);
-      matcher = PATTERN2.matcher(text);
+      Matcher matcher = HAXE3_PATTERN2.matcher(text);
 
       if (matcher.find()) {
         String group = matcher.group(1);
 
-        if (!compilerArguments2.contains(group)) {
-          compilerArguments2.add(new HXMLCompletionItem(group, matcher.group(2)));
+        if (!COMPILER_ARGUMENTS2.contains(group)) {
+          COMPILER_ARGUMENTS2.add(new HXMLCompletionItem(group, matcher.group(2)));
         }
       }
       else
       {
-        matcher = PATTERN.matcher(text);
+        matcher = HAXE3_PATTERN.matcher(text);
 
         if (matcher.find()) {
           String group = matcher.group(1);
 
-          if (!compilerArguments.contains(group)) {
+          if (!COMPILER_ARGUMENTS.contains(group)) {
             String description = matcher.group(3);
             String group2 = matcher.group(2);
             if (group2 != null) {
               group2 = group + " " + group2;
             }
-            compilerArguments.add(new HXMLCompletionItem(group, description, group2));
+            COMPILER_ARGUMENTS.add(new HXMLCompletionItem(group, description, group2));
           }
         }
       }
     }
 
-    if (!compilerArguments.contains("D")) {
-      compilerArguments.add(new HXMLCompletionItem("D"));
+    if (!COMPILER_ARGUMENTS.contains("D")) {
+      COMPILER_ARGUMENTS.add(new HXMLCompletionItem("D"));
     }
+  }
+  private void addHaxe4CompilerArguments(List<String> strings) {
+    for (int i = 0; i < strings.size(); i++) {
+      String text = strings.get(i);
+
+      Matcher matcher = HAXE4_PATTERN.matcher(text);
 
-    COMPILER_ARGUMENTS = compilerArguments;
-    COMPILER_ARGUMENTS2 = compilerArguments2;
+        if (matcher.find()) {
+          String shortCmd = getTextFromGroup(matcher, "short");
+          String longCmd = getTextFromGroup(matcher, "long");
+
+          if (shortCmd != null && !COMPILER_ARGUMENTS.contains(shortCmd)) {
+            String description = getTextFromGroup(matcher, "description");
+            StringJoiner presentation = new StringJoiner(" ");
+            String params = getTextFromGroup(matcher, "params");
+            String params2 = getTextFromGroup(matcher, "params2");
+            presentation.add(shortCmd);
+            if (params != null)  presentation.add(params);
+            if (params2 != null)  presentation.add(params2);
+            COMPILER_ARGUMENTS.add(new HXMLCompletionItem(shortCmd, description,  presentation.toString()));
+          }
+
+          if (longCmd != null && !COMPILER_ARGUMENTS2.contains(longCmd)) {
+            String description = getTextFromGroup(matcher, "description");
+            StringJoiner presentation = new StringJoiner(" ");
+            String params = getTextFromGroup(matcher, "params");
+            String params2 = getTextFromGroup(matcher, "params2");
+            presentation.add(longCmd);
+            if (params != null)  presentation.add(params);
+            if (params2 != null)  presentation.add(params2);
+
+            COMPILER_ARGUMENTS2.add(new HXMLCompletionItem(longCmd, description, presentation.toString()));
+          }
+        }
+      }
+  }
+
+  private String getTextFromGroup(Matcher matcher, String groupName) {
+    try {
+      return matcher.group(groupName);
+    }catch (IllegalArgumentException e) {
+      // group not found
+      return null;
+    }
   }
 
   private List<String> getStrings(ArrayList<String> commandLine) {
@@ -96,7 +142,7 @@ private List<String> getStrings(ArrayList<String> commandLine) {
     commandLine.add(HaxeHelpUtil.getHaxePath(module));
     commandLine.add("--help");
 
-    List<String> strings = HaxelibCommandUtils.getProcessStderr(commandLine, HaxeSdkUtilBase.getSdkData(module));
+    List<String> strings = HaxelibCommandUtils.getProcessStdout(commandLine, HaxeSdkUtilBase.getSdkData(module));
     if (strings.size() > 0) {
       strings.remove(0);
     }
@@ -104,10 +150,10 @@ private List<String> getStrings(ArrayList<String> commandLine) {
   }
 
   public HXMLCompilerArgumentsCompletionContributor() {
-    if (COMPILER_ARGUMENTS == null) {
+    if (COMPILER_ARGUMENTS.isEmpty()) {
       getCompilerArguments();
     }
-    extend(CompletionType.BASIC, PlatformPatterns.psiElement(HXMLTypes.OPTION).withLanguage(HXMLLanguage.INSTANCE),
+    extend(CompletionType.BASIC, PlatformPatterns.psiElement(HXMLTypes.KEY_TOKEN).withLanguage(HXMLLanguage.INSTANCE),
            new CompletionProvider<CompletionParameters>() {
              @Override
              protected void addCompletions(@NotNull CompletionParameters parameters,
diff --git a/src/common/com/intellij/plugins/haxe/ide/HXMLDefineCompletionContributor.java b/src/common/com/intellij/plugins/haxe/ide/HXMLDefineCompletionContributor.java
index 1b838091e..508161dbe 100644
--- a/src/common/com/intellij/plugins/haxe/ide/HXMLDefineCompletionContributor.java
+++ b/src/common/com/intellij/plugins/haxe/ide/HXMLDefineCompletionContributor.java
@@ -22,29 +22,40 @@
 import com.intellij.patterns.PlatformPatterns;
 import com.intellij.plugins.haxe.hxml.psi.HXMLDefine;
 import com.intellij.plugins.haxe.hxml.psi.HXMLTypes;
+import com.intellij.plugins.haxe.hxml.psi.HXMLValue;
 import com.intellij.plugins.haxe.util.HaxeHelpCache;
 import com.intellij.util.ProcessingContext;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
 
+import static com.intellij.patterns.PlatformPatterns.psiElement;
+
 /**
  * Created by as3boyan on 19.11.14.
  */
 public class HXMLDefineCompletionContributor extends CompletionContributor {
   public HXMLDefineCompletionContributor() {
     final List<HXMLCompletionItem> defines = HaxeHelpCache.getInstance().getDefines();
-    extend(CompletionType.BASIC, PlatformPatterns.psiElement(HXMLTypes.VALUE).withParent(HXMLDefine.class),
-           new CompletionProvider<CompletionParameters>() {
-             @Override
-             protected void addCompletions(@NotNull CompletionParameters parameters,
-                                           ProcessingContext context,
-                                           @NotNull CompletionResultSet result) {
-               for (int i = 0; i < defines.size(); i++) {
-                 HXMLCompletionItem completionItem = defines.get(i);
-                 result.addElement(LookupElementBuilder.create(completionItem.name).withTailText(" " + completionItem.description, true));
-               }
-             }
-           });
+
+    // intelliJ 2018 and older
+    extend(CompletionType.BASIC, PlatformPatterns.psiElement(HXMLTypes.VALUE).withParent(HXMLDefine.class), getProvider(defines));
+    // intelliJ 2019 and newer
+    extend(CompletionType.BASIC, PlatformPatterns.psiElement().withParent(HXMLValue.class).withSuperParent(2, HXMLDefine.class), getProvider(defines));
+  }
+
+  @NotNull
+  private CompletionProvider<CompletionParameters> getProvider(List<HXMLCompletionItem> defines) {
+    return new CompletionProvider<CompletionParameters>() {
+      @Override
+      protected void addCompletions(@NotNull CompletionParameters parameters,
+                                    ProcessingContext context,
+                                    @NotNull CompletionResultSet result) {
+        for (int i = 0; i < defines.size(); i++) {
+          HXMLCompletionItem completionItem = defines.get(i);
+          result.addElement(LookupElementBuilder.create(completionItem.name).withTailText(" " + completionItem.description, true));
+        }
+      }
+    };
   }
 }
diff --git a/src/common/com/intellij/plugins/haxe/ide/HXMLHaxelibCompletionContributor.java b/src/common/com/intellij/plugins/haxe/ide/HXMLHaxelibCompletionContributor.java
index 9740278fc..afa1386f1 100644
--- a/src/common/com/intellij/plugins/haxe/ide/HXMLHaxelibCompletionContributor.java
+++ b/src/common/com/intellij/plugins/haxe/ide/HXMLHaxelibCompletionContributor.java
@@ -20,10 +20,13 @@
 import com.intellij.codeInsight.completion.*;
 import com.intellij.codeInsight.lookup.LookupElementBuilder;
 import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.patterns.PlatformPatterns;
 import com.intellij.plugins.haxe.haxelib.HaxelibCache;
 import com.intellij.plugins.haxe.hxml.HXMLLanguage;
 import com.intellij.plugins.haxe.hxml.psi.HXMLLib;
+import com.intellij.plugins.haxe.hxml.psi.HXMLTokenType;
 import com.intellij.plugins.haxe.hxml.psi.HXMLTypes;
+import com.intellij.plugins.haxe.hxml.psi.HXMLValue;
 import com.intellij.util.ProcessingContext;
 import org.jetbrains.annotations.NotNull;
 
@@ -46,22 +49,29 @@ public HXMLHaxelibCompletionContributor() {
     availableHaxelibs = haxelibCache.getAvailableHaxelibs();
     localHaxelibs = haxelibCache.getLocalHaxelibs();
 
-    extend(CompletionType.BASIC, psiElement(HXMLTypes.VALUE).withParent(HXMLLib.class).withLanguage(HXMLLanguage.INSTANCE),
-           new CompletionProvider<CompletionParameters>() {
-             @Override
-             protected void addCompletions(@NotNull CompletionParameters parameters,
-                                           ProcessingContext context,
-                                           @NotNull CompletionResultSet result) {
-               for (int i = 0; i < availableHaxelibs.size(); i++) {
-                 result.addElement(LookupElementBuilder.create(availableHaxelibs.get(i))
-                                     .withTailText(" available at haxelib", true));
-               }
+    // intelliJ 2018 and older
+    extend(CompletionType.BASIC, psiElement(HXMLTypes.VALUE).withParent(HXMLLib.class).withLanguage(HXMLLanguage.INSTANCE),  getProvider());
+    // intelliJ 2019 and newer
+    extend(CompletionType.BASIC, PlatformPatterns.psiElement().withParent(HXMLValue.class).withSuperParent(2, HXMLLib.class).withLanguage(HXMLLanguage.INSTANCE), getProvider());
+  }
+
+  @NotNull
+  private CompletionProvider<CompletionParameters> getProvider() {
+    return new CompletionProvider<CompletionParameters>() {
+      @Override
+      protected void addCompletions(@NotNull CompletionParameters parameters,
+                                    ProcessingContext context,
+                                    @NotNull CompletionResultSet result) {
+        for (int i = 0; i < availableHaxelibs.size(); i++) {
+          result.addElement(LookupElementBuilder.create(availableHaxelibs.get(i))
+                              .withTailText(" available at haxelib", true));
+        }
 
-               for (int i = 0; i < localHaxelibs.size(); i++) {
-                 result.addElement(LookupElementBuilder.create(localHaxelibs.get(i))
-                                     .withTailText(" installed", true));
-               }
-             }
-           });
+        for (int i = 0; i < localHaxelibs.size(); i++) {
+          result.addElement(LookupElementBuilder.create(localHaxelibs.get(i))
+                              .withTailText(" installed", true));
+        }
+      }
+    };
   }
 }