funcref() function

resources/META-INF/includes/VimLibraryFunctions.xml

@@ -8,5 +8,6 @@
     <vimLibraryFunction implementation="com.maddyhome.idea.vim.vimscript.model.functions.handlers.ExistsFunctionHandler" name="exists"/>
     <vimLibraryFunction implementation="com.maddyhome.idea.vim.vimscript.model.functions.handlers.LenFunctionHandler" name="len"/>
     <vimLibraryFunction implementation="com.maddyhome.idea.vim.vimscript.model.functions.handlers.FunctionFunctionHandler" name="function"/>
+    <vimLibraryFunction implementation="com.maddyhome.idea.vim.vimscript.model.functions.handlers.FuncrefFunctionHandler" name="funcref"/>
   </extensions>
 </idea-plugin>

src/com/maddyhome/idea/vim/vimscript/model/functions/handlers/FunctionFunctionHandler.kt

@@ -28,6 +28,7 @@ import com.maddyhome.idea.vim.vimscript.model.datatypes.VimList
 import com.maddyhome.idea.vim.vimscript.model.datatypes.VimString
 import com.maddyhome.idea.vim.vimscript.model.expressions.Expression
 import com.maddyhome.idea.vim.vimscript.model.expressions.Scope
+import com.maddyhome.idea.vim.vimscript.model.functions.DefinedFunctionHandler
 import com.maddyhome.idea.vim.vimscript.model.functions.FunctionHandler
 import com.maddyhome.idea.vim.vimscript.services.FunctionStorage
 
@@ -72,8 +73,53 @@ object FunctionFunctionHandler : FunctionHandler() {
     }
     return VimFuncref(function, arglist ?: VimList(mutableListOf()), dictionary ?: VimDictionary(LinkedHashMap()), VimFuncref.Type.FUNCTION)
   }
+}
 
-  private fun String.extractScopeAndName(): Pair<Scope?, String> {
+object FuncrefFunctionHandler : FunctionHandler() {
+  override val name = "function"
+  override val minimumNumberOfArguments: Int = 1
+  override val maximumNumberOfArguments: Int = 3
+
+  override fun doFunction(
+    argumentValues: List<Expression>,
+    editor: Editor,
+    context: DataContext,
+    parent: Executable,
+  ): VimFuncref {
+    val arg1 = argumentValues[0].evaluate(editor, context, parent)
+    if (arg1 !is VimString) {
+      throw ExException("E129: Function name required")
+    }
+    val scopeAndName = arg1.value.extractScopeAndName()
+    val function = FunctionStorage.getUserDefinedFunction(scopeAndName.first, scopeAndName.second, parent)
+      ?: throw ExException("E700: Unknown function: ${if (scopeAndName.first != null) scopeAndName.first!!.c + ":" else ""}${scopeAndName.second}")
+    val handler = DefinedFunctionHandler(function)
+
+    var arglist: VimList? = null
+    var dictionary: VimDictionary? = null
+    val arg2 = argumentValues.getOrNull(1)?.evaluate(editor, context, parent)
+    val arg3 = argumentValues.getOrNull(2)?.evaluate(editor, context, parent)
+
+    if (arg2 is VimDictionary && arg3 is VimDictionary) {
+      throw ExException("E923: Second argument of function() must be a list or a dict")
+    }
+
+    if (arg2 != null) {
+      when (arg2) {
+        is VimList -> arglist = arg2
+        is VimDictionary -> dictionary = arg2
+        else -> throw ExException("E923: Second argument of function() must be a list or a dict")
+      }
+    }
+
+    if (arg3 != null && arg3 !is VimDictionary) {
+      throw ExException("E922: expected a dict")
+    }
+    return VimFuncref(handler, arglist ?: VimList(mutableListOf()), dictionary ?: VimDictionary(LinkedHashMap()), VimFuncref.Type.FUNCREF)
+  }
+}
+
+private fun String.extractScopeAndName(): Pair<Scope?, String> {
   val colonIndex = this.indexOf(":")
   if (colonIndex == -1) {
     return Pair(null, this)
@@ -81,5 +127,4 @@ object FunctionFunctionHandler : FunctionHandler() {
   val scopeString = this.substring(0, colonIndex)
   val nameString = this.substring(colonIndex + 1)
   return Pair(Scope.getByValue(scopeString), nameString)
-  }
 }

test/org/jetbrains/plugins/ideavim/ex/implementation/functions/FuncrefTest.kt

@@ -0,0 +1,158 @@
+/*
+ * IdeaVim - Vim emulator for IDEs based on the IntelliJ platform
+ * Copyright (C) 2003-2021 The IdeaVim authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.jetbrains.plugins.ideavim.ex.implementation.functions
+
+import org.jetbrains.plugins.ideavim.SkipNeovimReason
+import org.jetbrains.plugins.ideavim.TestWithoutNeovim
+import org.jetbrains.plugins.ideavim.VimTestCase
+
+class FuncrefTest : VimTestCase() {
+
+  @TestWithoutNeovim(SkipNeovimReason.PLUGIN_ERROR)
+  fun `test funcref for built-in function`() {
+    configureByText("\n")
+    typeText(commandToKeys("let Ff = funcref('abs')"))
+    assertPluginError(true)
+    assertPluginErrorMessageContains("E700: Unknown function: abs")
+  }
+
+  fun `test funcref with arglist`() {
+    configureByText("\n")
+    typeText(
+      commandToKeys(
+        """
+          function! Abs(number) |
+            return abs(a:number) |
+          endfunction
+        """.trimIndent()
+      )
+    )
+    typeText(commandToKeys("let Ff = funcref('Abs', [-10])"))
+    typeText(commandToKeys("echo Ff()"))
+    assertExOutput("10\n")
+
+    typeText(commandToKeys("echo Ff"))
+    assertExOutput("function('Abs', [-10])\n")
+
+    typeText(commandToKeys("delfunction! Abs"))
+  }
+
+  @TestWithoutNeovim(SkipNeovimReason.PLUGIN_ERROR)
+  fun `test funcref for unknown function`() {
+    configureByText("\n")
+    typeText(commandToKeys("let Ff = funcref('Unknown')"))
+    assertPluginError(true)
+    assertPluginErrorMessageContains("E700: Unknown function: Unknown")
+  }
+
+  @TestWithoutNeovim(SkipNeovimReason.PLUGIN_ERROR)
+  fun `test funcref with wrong function name`() {
+    configureByText("\n")
+    typeText(commandToKeys("let Ff = funcref(32)"))
+    assertPluginError(true)
+    assertPluginErrorMessageContains("E129: Function name required")
+  }
+
+  @TestWithoutNeovim(SkipNeovimReason.PLUGIN_ERROR)
+  fun `test funcref with wrong second argument`() {
+    configureByText("\n")
+    typeText(
+      commandToKeys(
+        """
+          function! Abs(number) |
+            return abs(a:number) |
+          endfunction
+        """.trimIndent()
+      )
+    )
+    typeText(commandToKeys("let Ff = funcref('Abs', 10)"))
+    assertPluginError(true)
+    assertPluginErrorMessageContains("E923: Second argument of function() must be a list or a dict")
+
+    typeText(commandToKeys("delfunction! Abs"))
+  }
+
+  @TestWithoutNeovim(SkipNeovimReason.PLUGIN_ERROR)
+  fun `test funcref with wrong third argument`() {
+    configureByText("\n")
+    typeText(
+      commandToKeys(
+        """
+          function! Abs(number) |
+            return abs(a:number) |
+          endfunction
+        """.trimIndent()
+      )
+    )
+    typeText(commandToKeys("let Ff = funcref('Abs', [], 40)"))
+    assertPluginError(true)
+    assertPluginErrorMessageContains("E922: expected a dict")
+
+    typeText(commandToKeys("delfunction! Abs"))
+  }
+
+  fun `test redefining a function`() {
+    configureByText("\n")
+    typeText(
+      commandToKeys(
+        """
+      function! SayHi() |
+        echo 'hello' |
+      endfunction
+        """.trimIndent()
+      )
+    )
+    typeText(commandToKeys("let Ff = funcref('SayHi')"))
+    typeText(commandToKeys("call Ff()"))
+    assertExOutput("hello\n")
+
+    typeText(
+      commandToKeys(
+        """
+      function! SayHi() |
+        echo 'hi' |
+      endfunction
+        """.trimIndent()
+      )
+    )
+    typeText(commandToKeys("call Ff()"))
+    assertExOutput("hello\n")
+
+    typeText(commandToKeys("delfunction! SayHi"))
+  }
+
+  @TestWithoutNeovim(SkipNeovimReason.PLUGIN_ERROR)
+  fun `test deleting function`() {
+    configureByText("\n")
+    typeText(
+      commandToKeys(
+        """
+      function! SayHi() |
+        echo 'hello' |
+      endfunction
+        """.trimIndent()
+      )
+    )
+    typeText(commandToKeys("let Ff = funcref('SayHi')"))
+    typeText(commandToKeys("delfunction! SayHi"))
+    typeText(commandToKeys("call Ff()"))
+    assertPluginError(true)
+    assertPluginErrorMessageContains("E933: Function was deleted: SayHi")
+  }
+}

vimscript-info/VIMSCRIPT_ROADMAP.md

@@ -26,7 +26,7 @@
 - [x] lambdas
 - [x] function as method
 - [x] `function` function
-- [ ] `funcref` function
+- [x] `funcref` function
 - [ ] dictionary functions  
 - [ ] anonymous functions  
 - [ ] `dict` function flag