Re-merge 'devel' into 'master'.

.gitignore

@@ -1,3 +1,2 @@
+.nimcache/
 nimcache/
-nimblecache/
-htmldocs/

.travis.yml

@@ -7,15 +7,38 @@ language: c
 
 os: linux
 dist: bionic
-
 sudo: required
 
 services:
   - docker
 
-before_install:
-  - docker pull nimlang/nim
 
-script:
-  - docker run nimlang/nim nim --version
-  - docker run -v "$(pwd):/project" -w /project nimlang/nim sh -c "nimble install -dy && nimble test"
+env:
+  global:
+    - DOCKER_IMG='nimlang/nim:latest-alpine'
+
+
+_shared_job: &shared_job
+  before_install:
+    - docker pull "$DOCKER_IMG"
+  script:
+    - docker run "$DOCKER_IMG" nim --version
+    - docker run -v "$(pwd):/project" -w /project -e NIM_BACKEND="$NIM_BACKEND" "$DOCKER_IMG" sh -c "nimble install -dy && nimble test"
+
+
+jobs:
+  include:
+    - name: Test suite (C)
+      env: NIM_BACKEND='cc'
+      <<: *shared_job
+
+    - name: Test suite (C++)
+      env: NIM_BACKEND='cpp'
+      <<: *shared_job
+
+    - name: Test suite (Node.js)
+      env: NIM_BACKEND='js'
+      <<: *shared_job
+
+  allow_failures:
+    - env: NIM_BACKEND='js'

README.md

@@ -1,2 +1,3 @@
 # nim-iterator-stream-experiment
+
 An attempt at providing a replacement for iterators in Nim with an API similar to Java 8 Stream.

nim_iterator_stream_experiment.nimble

@@ -1,32 +1,155 @@
-# Package
+version = "0.1.0"
+author = "thenjip"
+description = "An attempt at providing a replacement for closure iterators in Nim with an API similar to Java 8 Stream."
+license = "MIT"
+srcDir = "src"
 
-version       = "0.1.0"
-author        = "thenjip"
-description   = "An attempt at providing a replacement for closure iterators in Nim with an API similar to Java 8 Stream."
-license       = "MIT"
-srcDir        = "src"
+requires "nim >= 1.2.0"
 
 
 
-# Dependencies
+import std/[options, os, sequtils, strformat, strutils, sugar]
+
+
+
+type
+  AbsolutePath = string
+  RelativePath = string
+
+  Backend {.pure.} = enum
+    C
+    Cxx
+    Js
+
+  InvalidEnvVarValueError = object of CatchableError
+
+
+
+func newInvalidEnvVarValueError (
+  name: string;
+  value: string
+): ref InvalidEnvVarValueError =
+  InvalidEnvVarValueError.newException(fmt"""{name}="{value}"""")
+
+
+func findFirst [I, T](a: array[I, T]; predicate: I -> bool): Option[I] =
+  result = I.none()
+
+  for i, item in a:
+    if i.predicate():
+      return i.some()
+
+
+
+func projectName (): string =
+  const name = "nim_iterator_stream_experiment"
+
+  name
+
+
+
+proc moduleDir (): RelativePath =
+  srcDir / projectName()
+
+
+func nimcacheDirName (): string =
+  const name = ".nimcache"
+
+  name
+
+
+func nimcacheDir (): AbsolutePath =
+  const dir = projectDir() / nimcacheDirName()
+
+  dir
 
-requires "nim >= 1.2.0"
 
 
+func backendEnvVarName (): string =
+  const name = "NIM_BACKEND"
 
-import std/[os, sequtils, strformat, strutils]
+  name
 
 
+func nimCmdNames (): array[Backend, string] =
+  const names = ["cc", "cpp", "js"]
 
-task test, "":
-  withDir srcDir:
+  names
+
+
+func nimCmdName (backend: Backend): string =
+  nimCmdNames()[backend]
+
+
+proc readBackendFromEnv (): Option[Backend] {.
+  raises: [InvalidEnvVarValueError, ValueError]
+.} =
+  let envVarName = backendEnvVarName()
+
+  if envVarName.existsEnv():
     let
-      projectName = "nim_iterator_stream_experiment"
-      cmdElements =
-        [
-          "c",
-          "-r",
-          projectDir() / srcDir / fmt"{projectName}{ExtSep}nim"
-        ]
-
-    cmdElements.foldl([a, b.quoteShell()].join($' '), "").selfExec()
+      envVarValue = envVarName.getEnv()
+      backendFound = nimCmdNames().findFirst(b => b.nimCmdName() == envVarValue)
+
+    if backendFound.isSome():
+      backendFound
+    else:
+      raise newInvalidEnvVarValueError(envVarName, envVarValue)
+  else:
+    Backend.none()
+
+
+
+func testTaskDescription (): string =
+  func backendChoice (): string =
+    nimCmdNames().`@`().foldl(a & '|' & b)
+
+  @[
+    fmt"""Build the test suite in "{nimcacheDir()}{DirSep}" and run it.""",
+    fmt"""The backend can be specified in the environment variable "{backendEnvVarName()}=({backendChoice()})"."""
+  ].foldl(a & ' ' & b)
+
+
+
+task test, testTaskDescription():
+  func buildGenDir (module: RelativePath; backend: Backend): AbsolutePath =
+    let (dir, file) = module.splitPath()
+
+    nimcacheDir() / backend.nimCmdName() / dir / file
+
+
+  proc buildCmdLineParts (
+    module: RelativePath;
+    backendSupplier: () -> Option[Backend]
+  ): seq[string] =
+    func handleJsFlags (backend: Backend): seq[string] =
+      if backend == Backend.Js:
+        @["-d:nodejs"]
+      else:
+        @[]
+
+    let
+      backend = backendSupplier().get(Backend.C)
+      genDir = module.buildGenDir(backend).quoteShell()
+      nimCmd = backend.nimCmdName()
+      shortOptions = @["-r"] & backend.handleJsFlags()
+      longOptions = @[fmt"--nimcache:{genDir}", fmt"--outdir:{genDir}"]
+
+    @[nimCmd].concat(shortOptions, longOptions, @[module])
+
+
+  withDir moduleDir():
+    for file in system.getCurrentDir().walkDirRec(relative = true):
+      if file.endsWith(fmt"{ExtSep}nim"):
+        file
+          .buildCmdLineParts(readBackendFromEnv)
+          .foldl(a & $' ' & b.quoteShell())
+          .selfExec()
+
+
+
+task clean_test, """Remove the build directory of the "test" task.""":
+  let buildDir = nimcacheDir()
+
+  if system.existsDir(buildDir):
+    buildDir.rmDir()