Added main.nim (finally)

src/main.nim

@@ -0,0 +1,66 @@
+# 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.
+import backend/lexer
+import backend/parser
+import backend/optimizer
+
+
+import strformat
+
+var source: string
+var filename = "test.jpl"
+var tokens: seq[Token]
+var tree: seq[ASTNode]
+var optimized: tuple[tree: seq[ASTNode], warnings: seq[Warning]]
+
+echo "NimVM REPL\n"
+while true:
+    try:
+        stdout.write(">>> ")
+        source = stdin.readLine()
+    except IOError:
+        echo ""
+        break
+
+    echo &"Processing: '{source}'\n"
+    try:
+        tokens = initLexer().lex(source, filename)
+        tree = initParser().parse(tokens, filename)
+        optimized = initOptimizer().optimize(tree)
+    except:
+        echo getCurrentExceptionMsg()
+        continue
+
+    echo "Tokenization step: "
+    for token in tokens:
+        echo "\t", token
+    echo ""
+
+    echo &"Parsing step: "
+    for node in tree:
+        echo "\t", node
+    echo ""
+
+    echo &"Optimization step:"
+    for node in optimized.tree:
+        echo "\t", node
+    echo ""
+
+    stdout.write(&"Produced warnings: ")
+    if optimized.warnings.len() > 0:
+        echo ""
+        for warning in optimized.warnings:
+            echo "\t", warning
+    else:
+        stdout.write("No warnings produced\n")