[vm, misc] Removed completely unnecessary and unused vm @source, and added help and clean makefile rules.

.gitignore

@@ -5,6 +5,8 @@
 /bin/
 /.shards/
 
+# Crystal generated docs
+/docs/
 # The myst executable
 /myst
 # DWARF file from compiling on macOS

Makefile

@@ -1,13 +1,22 @@
-.PHONY: spec
-spec:
+.PHONY: help clean spec mystspec
+
+spec:      ## Runs all specs
 	crystal spec
 	crystal run src/myst_cli.cr -- spec/myst/spec.mt
 
-mystspec:
+myst-spec: ## Runs just the in-language specs
 	crystal run src/myst_cli.cr -- spec/myst/spec.mt
 
-default:
+build:     ## Builds myst into an executable
 	shards build
 
-check:
+check:     ## Runs all crystal specs
 	crystal spec/
+
+clean:     ## Cleans (deletes) docs and executables
+	rm -rf docs
+	rm bin/*
+
+# https://gist.github.com/prwhite/8168133 "Help target"
+help:      ## Show this help.
+	@fgrep -h "##" $(MAKEFILE_LIST) | fgrep -v fgrep | sed -e 's/\\$$//' | sed -e 's/##//'

src/myst/vm.cr

@@ -13,9 +13,7 @@ module Myst
       # Just telling warn() we're not in test mode (test  declaration in
       # spec/spec_helper.cr)
       ENV["MYST_ENV"] = product? ? "prod" : "test"
-
-
-      @source = source
+
       @interpreter = Interpreter.new
       @semantic_visitor = Semantic::Visitor.new
 
@@ -31,7 +29,7 @@ module Myst
       @program = uninitialized Expressions
       # Parse the program into an AST
       # This can throw an error (ParseError)
-      @program = Parser.new(@source, source_name).parse
+      @program = Parser.new(source, source_name).parse
     end
 
     def self.for_file(source_file : String, *, with_stdlib? : Bool = true, use_stdios? : Bool = false, product? : Bool = true)
@@ -93,7 +91,7 @@ module Myst
       end
     end
 
-    # Runs the `@source` io
+    # Runs the `@program` property
     def run
       # Interpret the program
       run(@program.not_nil!)