cii: Add get_word

cii/CMakeLists.txt

@@ -49,6 +49,7 @@ if (BUILD_TESTING)
       )
 
   add_executable(cii_table_test
+      tests/table_test.c
       tests/get_word.c
       tests/get_word.h
       )

cii/tests/get_word.c

@@ -2,4 +2,50 @@
 // Use of this source is governed by GNU General Public License
 // that can be found in the LICENSE file.
 
-#include "get_word.h"
+#include "get_word.h"
+
+#include <ctype.h>
+#include <string.h>
+
+#include "cii/assert.h"
+
+int get_word(FILE* fp, char* buf, size_t buf_size,
+             int first(int c), int rest(int c)) {
+  assert(fp != NULL);
+  assert(buf != NULL);
+  assert(buf_size > 1);
+  assert(first != NULL);
+  assert(rest != NULL);
+
+  int c = getc(fp);
+  int i = 0;
+  for (/* empty */; c != EOF; c = getc(fp)) {
+    if (first(c) == 0) {
+      // store c in buffer.
+      if (i < buf_size - 1) {
+        buf[i] = (char)c;
+        i += 1;
+      }
+
+      c = getc(fp);
+      break;
+    }
+  }
+  for (/* empty */; c != EOF && rest(c) == 0; c = getc(fp)) {
+    // store c in buffer.
+    if (i < buf_size - 1) {
+      buf[i] = (char)c;
+      i += 1;
+    }
+  }
+  if (i < buf_size) {
+    buf[i] = '\0';
+  } else {
+    buf[buf_size - 1] = '\0';
+  }
+  if (c != EOF) {
+    ungetc(c, fp);
+  }
+
+  return i > 0;
+}

cii/tests/get_word.h

@@ -5,4 +5,28 @@
 #ifndef CII_TESTS_GET_WORD_H_
 #define CII_TESTS_GET_WORD_H_
 
+#include <stdio.h>
+
+/**
+ * Consumes the next word in the file opened on |fp|, stores it as a null-terminated
+ * string in |buf|, and returns one.
+ *
+ * When it reaches end of file without consuming a word, it returns zero.
+ *
+ * A word is a contiguous sequence of characters, it starts with a character for
+ * which |first| returns nonzero value followed by characters for which |rest|
+ * returns nonzero values.
+ *
+ * If a word is longer than |buf_size - 2| characters, the excess characters are
+ * discarded.
+ * @param fp must be non-null.
+ * @param buf must be non-null.
+ * @param buf_size must exceed one.
+ * @param first must be non-null.
+ * @param rest must be non-null.
+ * @return
+ */
+extern int get_word(FILE* fp, char* buf, size_t buf_size,
+                    int first(int c), int rest(int c));
+
 #endif //CII_TESTS_GET_WORD_H_

cii/tests/table_test.c

@@ -0,0 +1,9 @@
+// Copyright (c) 2023 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by GNU General Public License
+// that can be found in the LICENSE file.
+
+#include "get_word.h"
+
+int main() {
+  return 0;
+}