[project @ 1998-12-02 13:17:09 by simonm]

[ghc-hetmet.git] / ghc / interpreter / charset.c

diff --git a/ghc/interpreter/charset.c b/ghc/interpreter/charset.c
new file mode 100644 (file)
index 0000000..a234a28
--- /dev/null
+++ b/ghc/interpreter/charset.c
@@ -0,0 +1,63 @@
+/* --------------------------------------------------------------------------
+ * Character set handling:
+ *
+ * Hugs follows Haskell 1.3 in assuming that input uses the ISO-8859-1
+ * character set.  The following code provides methods for classifying
+ * input characters according to the lexical structure specified by the
+ * report.  Hugs should still accept older programs because ASCII is
+ * essentially just a subset of the ISO character set.
+ *
+ * Notes: If you want to port Hugs to a machine that uses something
+ * substantially different from the ISO character set, then you will need
+ * to insert additional code to map between character sets.
+ *
+ * Relies, implicitly but for this comment, on assumption that NUM_CHARS=256.
+ * ------------------------------------------------------------------------*/
+
+#include "prelude.h"
+#include "storage.h"
+#include "connect.h"
+#include "charset.h"
+
+unsigned char   ctable[NUM_CHARS];
+
+Void initCharTab() {                    /* Initialize char decode table    */
+#define setRange(x,f,t) {Int i=f;   while (i<=t) ctable[i++] |=x;}
+#define setChars(x,s)   {char *p=s; while (*p)   ctable[(Int)*p++]|=x;}
+#define setCopy(x,c)    {Int i;                         \
+                         for (i=0; i<NUM_CHARS; ++i)    \
+                             if (isIn(i,c))             \
+                                 ctable[i]|=x;          \
+                        }
+
+    setRange(DIGIT,     '0','9');       /* ASCII decimal digits            */
+
+    setRange(SMALL,     'a','z');       /* ASCII lower case letters        */
+    setRange(SMALL,     223,246);       /* ISO lower case letters          */
+    setRange(SMALL,     248,255);       /* (omits division symbol, 247)    */
+
+    setRange(LARGE,     'A','Z');       /* ASCII upper case letters        */
+    setRange(LARGE,     192,214);       /* ISO upper case letters          */
+    setRange(LARGE,     216,222);       /* (omits multiplication, 215)     */
+
+    setRange(SYMBOL,    161,191);       /* Symbol characters + ':'         */
+    setRange(SYMBOL,    215,215);
+    setRange(SYMBOL,    247,247);
+    setChars(SYMBOL,    ":!#$%&*+./<=>?@\\^|-~");
+
+    setChars(IDAFTER,   "'_");          /* Characters in identifier        */
+    setCopy (IDAFTER,   (DIGIT|SMALL|LARGE));
+
+    setRange(SPACE,     ' ',' ');       /* ASCII space character           */
+    setRange(SPACE,     160,160);       /* ISO non breaking space          */
+    setRange(SPACE,     9,13);          /* special whitespace: \t\n\v\f\r  */
+
+    setChars(PRINT,     "(),;[]_`{}");  /* Special characters              */
+    setChars(PRINT,     " '\"");        /* Space and quotes                */
+    setCopy (PRINT,     (DIGIT|SMALL|LARGE|SYMBOL));
+
+#undef setRange
+#undef setChars
+#undef setCopy
+}
+