parser: add comments and [...]; main: add file mode

parser/parser.go

@@ -2,6 +2,7 @@ package parser
 
 import (
   "errors"
+  "regexp"
   "strconv"
   "strings"
 
@@ -18,8 +19,18 @@ func withoutEmpty(input []string) []string {
     return r
 }
 
+var comments = regexp.MustCompile(";.*")
+var whitespace = regexp.MustCompile("\\s")
+
+func explode(s string, start string, end string) string {
+  return strings.Replace(strings.Replace(s, start, " "+start+" ", -1), end, " "+end+" ", -1)
+}
+
 func tokenize(input string) []string {
-  return withoutEmpty(strings.Split(strings.Replace(strings.Replace(input, "(", " ( ", -1), ")", " ) ", -1), " "))
+  withoutComments := string(comments.ReplaceAll([]byte(input), []byte("")))
+  explodedParens := explode(withoutComments, "(", ")")
+  explodedBrackets := explode(explodedParens, "[", "]")
+  return withoutEmpty(whitespace.Split(explodedBrackets, -1))
 }
 
 func parseValue(input []string) (*ast.AST, error, []string) {
@@ -53,9 +64,16 @@ func parseValue(input []string) (*ast.AST, error, []string) {
   return &res, nil, input[1:]
 }
 
+func makeFn(bodyStatements []ast.AST) ast.AST {
+      body := ast.AST{ast.List, bodyStatements}
+      args := ast.AST{ast.List, []ast.AST{ast.AST{ast.Symbol, "_"}}}
+
+      return ast.AST{ast.List, []ast.AST{ast.AST{ast.Symbol, "fn"}, args, body}}
+}
+
 func parseToken(input []string) (*ast.AST, error, []string) {
   if len(input) == 0 {
-    return nil, errors.New("Unmatched '('"), input
+    return nil, errors.New("Unmatched '(' or '['"), input
   }
 
   if input[0][0] == '\'' {
@@ -94,6 +112,25 @@ func parseToken(input []string) (*ast.AST, error, []string) {
     case ")": {
       return nil, errors.New("Unmatched ')'"), input
     }
+    case "[": {
+      var l []ast.AST
+      input = input[1:]
+      for input[0] != "]" {
+        elem, err, newInput := parseToken(input)
+
+        if err != nil {
+          return nil, err, input
+        }
+
+        l = append(l, *elem)
+        input = newInput
+      }
+      res := makeFn(l)
+      return &res, nil, input[1:]
+    }
+    case "]": {
+      return nil, errors.New("Unmatched ']'"), input
+    }
   }
   return parseValue(input)
 }