1 files changed, 95 insertions, 0 deletions
diff --git a/cljcc-compiler/src/cljcc/lexer.clj b/cljcc-compiler/src/cljcc/lexer.clj
new file mode 100644
index 0000000..0bfa12f
--- /dev/null
+++ b/cljcc-compiler/src/cljcc/lexer.clj
@@ -0,0 +1,95 @@
+(ns cljcc.lexer
+  (:require
+   [cljcc.util :refer [newline? whitespace? read-number digit? letter-digit? letter? letter-digit-period?]]
+   [cljcc.core.exception :as exc]
+   [cljcc.token :as t]))
+
+(defn- lexer-ctx []
+  {:tokens []
+   :line 1
+   :col 1})
+
+(defn lex
+  ([source]
+   (lex source (lexer-ctx)))
+  ([[ch pk th :as source] {:keys [line col] :as ctx}]
+   (cond
+     (empty? source) (update ctx :tokens #(conj % (t/create :eof line col)))
+     (newline? ch) (recur (next source)
+                          (-> ctx
+                              (update :line inc)
+                              (update :col (fn [_] 1))))
+     (whitespace? ch) (recur (next source)
+                             (-> ctx
+                                 (update :col inc)))
+     (contains?
+      t/chrs-kind-map (str ch pk th)) (recur (next (next (next source)))
+                                             (-> ctx
+                                                 (update :col #(+ % 3))
+                                                 (update :tokens #(conj % (t/create (get t/chrs-kind-map (str ch pk th)) line col)))))
+     (contains?
+      t/chrs-kind-map (str ch pk)) (recur (next (next source))
+                                          (-> ctx
+                                              (update :col #(+ % 2))
+                                              (update :tokens #(conj % (t/create (get t/chrs-kind-map (str ch pk)) line col)))))
+     (contains?
+      t/chrs-kind-map ch) (recur (next source)
+                                 (-> ctx
+                                     (update :col inc)
+                                     (update :tokens #(conj % (t/create (get t/chrs-kind-map ch) line col)))))
+     (or (= \. ch) (digit? ch)) (let [[number rst] (read-number (apply str source) line col)
+                                      cnt (count number)
+                                      token (t/create :number line col number)]
+                                  (recur rst
+                                         (-> ctx
+                                             (update :col #(+ % cnt))
+                                             (update :tokens #(conj % token)))))
+     (letter? ch) (let [[chrs rst] (split-with letter-digit? source)
+                        lexeme (apply str chrs)
+                        cnt (count chrs)
+                        kind (t/identifier->kind lexeme)
+                        token (if (= :identifier kind)
+                                (t/create kind line col lexeme)
+                                (t/create kind line col))]
+                    (recur (apply str rst) (-> ctx
+                                               (update :col #(+ % cnt))
+                                               (update :tokens #(conj % token)))))
+     :else (exc/lex-error {:line line :col col}))))
+
+(comment
+
+  (-> "./test-programs/example.c"
+      slurp)
+
+  (-> "./test-programs/example.c"
+      slurp
+      lex)
+
+  (lex "int x = 100l;")
+
+  (lex "
+    if (!sign_extend(10, 10l)) {
+        return 1;
+    }
+")
+
+  (lex
+   "
+int main(void) {
+    if (!sign_extend(10, 10l)) {
+        return 1;
+    }
+
+    if (!sign_extend(-10, -10l)) {
+        return 2;
+    }
+
+    long l = (long) 100;
+    if (l != 100l) {
+        return 3;
+    }
+    return 0;
+}
+")
+
+  ())