Add modules, open port for reading

1 files changed, 31 insertions, 0 deletions

diff --git a/src/modules/lexer/lexer.scm b/src/modules/lexer/lexer.scm
new file mode 100644
index 0000000..0661fa6
--- /dev/null
+++ b/src/modules/lexer/lexer.scm
@@ -0,0 +1,31 @@
+(define-module (modules lexer lexer)
+  #:export (read-tokens-from-port))
+
+(define (read-tokens-from-port port)
+  ""
+  (display (read-char port)))
+
+(define (read-token)
+
+  (define (read-token-loop first-char)
+    (cond
+
+     ((or (char-whitespace? first-char))
+      (read-token)
+
+      ((eq? first-char #\()
+       (cons 'left-paren #\())
+      ((eq? first-char #\))
+       (cons 'right-paren #\)))
+      ((eq? first-char #\{)
+       (cons 'right-bracket #\{))
+      ((eq? first-char #\})
+       (cons 'right-bracket #\}))
+
+      (#t
+       (error "illegal lexical syntax")))))
+
+  (let ((first-char (read-char)))
+    (if (eof-object? first-char)
+        '()
+        (cons (read-token-loop first-char) '()))))