Make the various from_str functions return options

So that they can be used with user input without causing task
failures.

Closes #1335

4 files changed, 9 insertions, 14 deletions

diff --git a/src/comp/metadata/decoder.rs b/src/comp/metadata/decoder.rs
index 867497f37fd..06b0acdf4a1 100644
--- a/src/comp/metadata/decoder.rs
+++ b/src/comp/metadata/decoder.rs
@@ -95,13 +95,8 @@ fn variant_enum_id(d: ebml::doc) -> ast::def_id {
 }
 
 fn variant_disr_val(d: ebml::doc) -> option<int> {
-    alt ebml::maybe_get_doc(d, tag_disr_val) {
-      some(val_doc) {
-        let val_buf = ebml::doc_data(val_doc);
-        let val = int::parse_buf(val_buf, 10u);
-        ret some(val);
-      }
-      _ { ret none;}
+    option::chain(ebml::maybe_get_doc(d, tag_disr_val)) {|val_doc|
+        int::parse_buf(ebml::doc_data(val_doc), 10u)
     }
 }
 
diff --git a/src/comp/metadata/tydecode.rs b/src/comp/metadata/tydecode.rs
index 9bd7ee75512..5d97777c0fb 100644
--- a/src/comp/metadata/tydecode.rs
+++ b/src/comp/metadata/tydecode.rs
@@ -390,8 +390,8 @@ fn parse_def_id(buf: [u8]) -> ast::def_id {
     for b: u8 in crate_part { crate_part_vec += [b]; }
     for b: u8 in def_part { def_part_vec += [b]; }
 
-    let crate_num = uint::parse_buf(crate_part_vec, 10u) as int;
-    let def_num = uint::parse_buf(def_part_vec, 10u) as int;
+    let crate_num = option::get(uint::parse_buf(crate_part_vec, 10u)) as int;
+    let def_num = option::get(uint::parse_buf(def_part_vec, 10u)) as int;
     ret {crate: crate_num, node: def_num};
 }
 
diff --git a/src/comp/syntax/ast_util.rs b/src/comp/syntax/ast_util.rs
index 09242f40c42..b9d48cb5fb0 100644
--- a/src/comp/syntax/ast_util.rs
+++ b/src/comp/syntax/ast_util.rs
@@ -301,7 +301,7 @@ fn lit_to_const(lit: @lit) -> const_val {
       lit_str(s) { const_str(s) }
       lit_int(n, _) { const_int(n) }
       lit_uint(n, _) { const_uint(n) }
-      lit_float(n, _) { const_float(float::from_str(n)) }
+      lit_float(n, _) { const_float(option::get(float::from_str(n))) }
       lit_nil { const_int(0i64) }
       lit_bool(b) { const_int(b as i64) }
     }
diff --git a/src/comp/syntax/parse/lexer.rs b/src/comp/syntax/parse/lexer.rs
index aa989cb0f61..113ca056ed4 100644
--- a/src/comp/syntax/parse/lexer.rs
+++ b/src/comp/syntax/parse/lexer.rs
@@ -174,8 +174,8 @@ fn scan_digits(rdr: reader, radix: uint) -> str {
     while true {
         let c = rdr.curr;
         if c == '_' { rdr.bump(); cont; }
-        alt char::maybe_digit(c) {
-          some(d) if (d as uint) < radix {
+        alt char::to_digit(c, radix) {
+          some(d) {
             str::push_char(rslt, c);
             rdr.bump();
           }
@@ -229,7 +229,7 @@ fn scan_number(c: char, rdr: reader) -> token::token {
         if str::len_bytes(num_str) == 0u {
             rdr.fatal("no valid digits found for number");
         }
-        let parsed = u64::from_str(num_str, base as u64);
+        let parsed = option::get(u64::from_str(num_str, base as u64));
         alt tp {
           either::left(t) { ret token::LIT_INT(parsed as i64, t); }
           either::right(t) { ret token::LIT_UINT(parsed, t); }
@@ -276,7 +276,7 @@ fn scan_number(c: char, rdr: reader) -> token::token {
         if str::len_bytes(num_str) == 0u {
             rdr.fatal("no valid digits found for number");
         }
-        let parsed = u64::from_str(num_str, base as u64);
+        let parsed = option::get(u64::from_str(num_str, base as u64));
         ret token::LIT_INT(parsed as i64, ast::ty_i);
     }
 }