Begin implementing #fmt in rustc

1 files changed, 84 insertions, 0 deletions

diff --git a/src/comp/front/extfmt.rs b/src/comp/front/extfmt.rs
new file mode 100644
index 00000000..cb70805a
--- /dev/null
+++ b/src/comp/front/extfmt.rs
@@ -0,0 +1,84 @@
+/* The 'fmt' extension is modeled on the posix printf system.
+ * 
+ * A posix conversion ostensibly looks like this:
+ * 
+ * %[parameter][flags][width][.precision][length]type
+ * 
+ * Given the different numeric type bestiary we have, we omit the 'length'
+ * parameter and support slightly different conversions for 'type':
+ * 
+ * %[parameter][flags][width][.precision]type
+ * 
+ * we also only support translating-to-rust a tiny subset of the possible
+ * combinations at the moment.
+ */
+
+use std;
+
+import std.option;
+
+tag signedness {
+    signed;
+    unsigned;
+}
+
+tag caseness {
+    case_upper;
+    case_lower;
+}
+
+tag ty {
+    ty_bool;
+    ty_str;
+    ty_char;
+    ty_int(signedness);
+    ty_bits;
+    ty_hex(caseness);
+    // FIXME: More types
+}
+
+tag flag {
+    flag_left_justify;
+    flag_left_zero_pad;
+    flag_left_space_pad;
+    flag_plus_if_positive;
+    flag_alternate;
+}
+
+tag count {
+    count_is(int);
+    count_is_param(int);
+    count_is_next_param;
+    count_implied;
+}
+
+// A formatted conversion from an expression to a string
+tag conv {
+    conv_param(option.t[int]);
+    conv_flags(vec[flag]);
+    conv_width(count);
+    conv_precision(count);
+    conv_ty(ty);
+}
+
+// A fragment of the output sequence
+tag piece {
+    piece_string(str);
+    piece_conv(str);
+}
+
+fn expand_syntax_ext(vec[@ast.expr] args,
+                     option.t[@ast.expr] body) -> @ast.expr {
+    fail;
+}
+
+//
+// Local Variables:
+// mode: rust
+// fill-column: 78;
+// indent-tabs-mode: nil
+// c-basic-offset: 4
+// buffer-file-coding-system: utf-8-unix
+// compile-command: "make -k -C ../.. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
+// End:
+//