add tests for stdlib/ascii.jou (#407)

self_hosted/runs_wrong.txt

@@ -43,3 +43,4 @@ tests/wrong_type/assert.jou
 tests/wrong_type/cannot_be_indexed.jou
 tests/wrong_type/index.jou
 stdlib/ascii.jou
+tests/should_succeed/ascii_test.jou

src/print.c

@@ -19,7 +19,7 @@ static void print_string(const char *s, int len)
         else if (s[i] == '\n')
             printf("\\n");
         else
-            printf("\\x%02x", s[i]);     // TODO: \x is not yet recognized by the tokenizer
+            printf("\\x%02x", (unsigned char)s[i]);     // TODO: \x is not yet recognized by the tokenizer
     }
     putchar('"');
 }

stdlib/ascii.jou

@@ -2,27 +2,23 @@ import "stdlib/str.jou"
 import "stdlib/mem.jou"
 
 # Test if a string is ASCII only.
-# TODO: test
 def is_ascii(s: byte*) -> bool:
     for p = s; *p != '\0'; p++:
         if *p >= 128:
             return False
     return True
 
 # Check for '0', '1', ..., '9'.
-# TODO: test
 def is_ascii_digit(b: byte) -> bool:
     return '0' <= b and b <= '9'
 
 # Checks if the given byte is an ASCII punctuation character, such as '*' or '_' or '"'.
-# TODO: test
 def is_ascii_punctuation(b: byte) -> bool:
-    return strchr("!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~", b) != NULL
+    return b != '\0' and strchr("!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~", b) != NULL
 
 # Checks if the given byte is an ASCII whitespace character, such as ' ' or '\n'.
-# TODO: test
 def is_ascii_whitespace(b: byte) -> bool:
-    return strchr("\t\n\x0b\x0c\r\x1c\x1d\x1e\x1f ", b) != NULL
+    return b != '\0' and strchr("\t\n\x0b\x0c\r\x1c\x1d\x1e\x1f ", b) != NULL
 
 # Removes ASCII whitespace from both ends of a string in-place.
 # Similar to .strip() in Python or .trim() in JavaScript.

tests/should_succeed/ascii_test.jou

@@ -0,0 +1,35 @@
+import "stdlib/ascii.jou"
+import "stdlib/str.jou"
+
+def main() -> int:
+    assert is_ascii("hello")
+    assert is_ascii("hello world test!!! @$!")
+    assert is_ascii("")
+    assert not is_ascii("örkkimörkki")
+
+    assert is_ascii_digit('0')
+    assert is_ascii_digit('7')
+    assert is_ascii_digit('9')
+    assert not is_ascii_digit('x')
+    assert not is_ascii_digit('\0')
+
+    assert is_ascii_punctuation('!')
+    assert is_ascii_punctuation('_')
+    assert not is_ascii_punctuation('a')
+    assert not is_ascii_punctuation('2')
+    assert not is_ascii_punctuation('\0')
+
+    assert is_ascii_whitespace(' ')
+    assert is_ascii_whitespace('\t')
+    assert is_ascii_whitespace('\r')
+    assert is_ascii_whitespace('\n')
+    assert not is_ascii_whitespace('a')
+    assert not is_ascii_whitespace('.')
+    assert not is_ascii_whitespace('\0')
+
+    s: byte[100]
+    strcpy(s, "  hello world \r\n  \t ")
+    trim_ascii_whitespace(s)
+    assert strcmp(s, "hello world") == 0
+
+    return 0