From a6ef548c49538d9397fc9df1dd55ea04e9b95024 Mon Sep 17 00:00:00 2001
From: nocturn9x <hackhab@gmail.com>
Date: Mon, 2 Nov 2020 21:39:57 +0100
Subject: [PATCH] Moved main.nim to japl.nim

---
 src/japl.nim | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)
 create mode 100644 src/japl.nim

diff --git a/src/japl.nim b/src/japl.nim
new file mode 100644
index 0000000..66bb948
--- /dev/null
+++ b/src/japl.nim
@@ -0,0 +1,126 @@
+# Copyright 2020 Mattia Giambirtone
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+## Main entry point for the JAPL language
+
+
+import strformat
+import parseopt
+import os
+import config
+import vm
+
+
+proc repl() =
+    var bytecodeVM = initVM()
+    echo JAPL_VERSION_STRING
+    echo &"[Nim {NimVersion} on {hostOs} ({hostCPU})]"
+    when DEBUG_TRACE_VM:
+        echo "Debugger enabled, expect verbose output\n"
+        echo "==== Runtime Constants ====\n"
+        echo &"- FRAMES_MAX -> {FRAMES_MAX}"
+        echo "==== Debugger started ====\n"
+    var source: string = ""
+    while true:
+        try:
+            stdout.write("=> ")
+            source = readLine(stdin)
+        except IOError:
+            echo ""
+            bytecodeVM.freeVM()
+            break
+        except KeyboardInterrupt:
+            echo ""
+            bytecodeVM.freeVM()
+            break
+        if source == "//clear" or source == "// clear":
+            echo "\x1Bc"
+            echo JAPL_VERSION_STRING
+            echo &"[Nim {NimVersion} on {hostOs} ({hostCPU})]"
+            continue
+        elif source != "":
+            var result = bytecodeVM.interpret(source, true, "stdin")
+            when DEBUG_TRACE_VM:
+                echo &"Result: {result}"
+    when DEBUG_TRACE_VM:
+        echo "==== Debugger exits ===="
+
+
+proc main(file: string = "") =
+    if file == "":
+        repl()
+    else:
+        var sourceFile: File
+        try:
+            sourceFile = open(filename=file)
+        except IOError:
+            echo &"Error: '{file}' could not be opened, probably the file doesn't exist or you don't have permission to read it"
+            return
+        var source: string
+        try:
+            source = readAll(sourceFile)
+        except IOError:
+            echo &"Error: '{file}' could not be read, probably you don't have the permission to read it"
+        var bytecodeVM = initVM()
+        when DEBUG_TRACE_VM:
+            echo "Debugger enabled, expect verbose output\n"
+            echo "==== VM Constants ====\n"
+            echo &"- FRAMES_MAX -> {FRAMES_MAX}"
+            echo "==== Code starts ====\n"
+        var result = bytecodeVM.interpret(source, false, file)
+        bytecodeVM.freeVM()
+        when DEBUG_TRACE_VM:
+            echo &"Result: {result}"
+        when DEBUG_TRACE_VM:
+            echo "==== Code ends ===="
+
+
+when isMainModule:
+    var optParser = initOptParser(commandLineParams())
+    var file: string = ""
+    if paramCount() > 0:
+        if paramCount() notin 1..<2:
+            echo "usage: japl [filename]"
+            quit()
+    for kind, key, value in optParser.getopt():
+        case kind:
+            of cmdArgument:
+                file = key
+            of cmdLongOption:
+                case key:
+                    of "help":
+                        echo HELP_MESSAGE
+                        quit()
+                    of "version":
+                        echo JAPL_VERSION_STRING
+                        quit()
+                    else:
+                        echo &"error: unkown option '{key}'"
+                        quit()
+            of cmdShortOption:
+                case key:
+                    of "h":
+                        echo HELP_MESSAGE
+                        quit()
+                    of "v":
+                        echo JAPL_VERSION_STRING
+                        quit()
+                    else:
+                        echo &"error: unkown option '{key}'"
+                        quit()   
+            else:
+                echo "usage: japl [filename]"
+                quit()
+    main(file)
+