Refactored parsing code into its own module.

macros/src/error_decorator.rs

@@ -1,8 +1,7 @@
 use utils::*;
+use meta_item_parser::MetaItemParser;
 use super::{CATCH_STRUCT_PREFIX, CATCH_FN_PREFIX};
 
-use route_decorator::get_fn_decl;
-
 use syntax::codemap::{Span};
 use syntax::ast::{MetaItem};
 use syntax::ext::base::{Annotatable, ExtCtxt};
@@ -16,7 +15,7 @@ struct Params {
     code: KVSpanned<u16>,
 }
 
-fn get_error_params(ecx: &mut ExtCtxt, meta_item: &MetaItem) -> Params {
+fn get_error_params(ecx: &ExtCtxt, meta_item: &MetaItem) -> Params {
     // Ensure we've been supplied with a k = v meta item. Error out if not.
     let params = meta_item.expect_list(ecx, "Bad use. Expected: #[error(...)]");
 
@@ -49,7 +48,9 @@ fn get_error_params(ecx: &mut ExtCtxt, meta_item: &MetaItem) -> Params {
 
 pub fn error_decorator(ecx: &mut ExtCtxt, sp: Span, meta_item: &MetaItem,
           annotated: &Annotatable, push: &mut FnMut(Annotatable)) {
-    let (item, _fn_decl) = get_fn_decl(ecx, sp, annotated);
+    let parser = MetaItemParser::new(ecx, meta_item, annotated, &sp);
+    let item = parser.expect_item();
+
     let error_params = get_error_params(ecx, meta_item);
     debug!("Error parameters are: {:?}", error_params);
 

macros/src/lib.rs

@@ -13,6 +13,7 @@ mod errors_macro;
 mod route_decorator;
 mod error_decorator;
 mod derive_form;
+mod meta_item_parser;
 
 use rustc_plugin::Registry;
 use syntax::ext::base::SyntaxExtension;
@@ -39,4 +40,6 @@ pub fn plugin_registrar(reg: &mut Registry) {
         SyntaxExtension::MultiDecorator(Box::new(from_form_derive)));
     reg.register_macro("routes", routes_macro);
     reg.register_macro("errors", errors_macro);
+
+//     reg.register_macro("GET", get_macro);
 }

macros/src/meta_item_parser.rs

@@ -0,0 +1,211 @@
+use std::str::FromStr;
+
+use syntax::ext::base::{Annotatable, ExtCtxt};
+use syntax::ast::{Item, ItemKind, MetaItem, FnDecl};
+use syntax::codemap::{Span, Spanned, BytePos};
+use syntax::ptr::P;
+
+use utils::*;
+use rocket::Method;
+
+pub struct MetaItemParser<'a, 'c: 'a> {
+    attr_name: &'a str,
+    ctxt: &'a ExtCtxt<'c>,
+    meta_item: &'a MetaItem,
+    annotated: &'a Annotatable,
+    span: Span
+}
+
+pub struct ParamIter<'s, 'a, 'c: 'a> {
+    ctxt: &'a ExtCtxt<'c>,
+    span: Span,
+    string: &'s str
+}
+
+impl<'a, 'c> MetaItemParser<'a, 'c> {
+    pub fn new(ctxt: &'a ExtCtxt<'c>, meta_item: &'a MetaItem,
+               annotated: &'a Annotatable, span: &'a Span) -> MetaItemParser<'a, 'c> {
+        MetaItemParser {
+            attr_name: meta_item.name(),
+            ctxt: ctxt,
+            meta_item: meta_item,
+            annotated: annotated,
+            span: span.clone(),
+        }
+    }
+
+    fn bad_item(&self, expected: &str, got: &str, sp: Span) -> ! {
+        let msg_a = format!("Expected a {} item...", expected);
+        let msg_b = format!("...but found a {} item instead.", got);
+        self.ctxt.span_err(self.span, msg_a.as_str());
+        self.ctxt.span_fatal(sp, msg_b.as_str())
+    }
+
+
+    pub fn expect_item(&self) -> &'a P<Item> {
+        let bad_item = |name: &str, sp: Span| self.bad_item("regular", name, sp);
+
+        match *self.annotated {
+            Annotatable::Item(ref item) => item,
+            Annotatable::TraitItem(ref item) => bad_item("trait", item.span),
+            Annotatable::ImplItem(ref item) => bad_item("impl", item.span)
+        }
+    }
+
+    pub fn expect_fn_decl(&self) -> Spanned<&'a FnDecl> {
+        let item = self.expect_item();
+        let bad_item = |name: &str| self.bad_item("fn_decl", name, item.span);
+
+        let fn_decl: &P<FnDecl> = match item.node {
+             ItemKind::Fn(ref decl, _, _, _, _, _) => decl,
+             _ => bad_item("other")
+         };
+
+        span(fn_decl, item.span)
+    }
+
+    fn expect_list(&self) -> &'a Vec<P<MetaItem>> {
+        let msg = format!("Bad use. Expected: #[{}(...)]", self.attr_name);
+        self.meta_item.expect_list(self.ctxt, msg.as_str())
+    }
+
+    pub fn iter_params<'s>(&self, from: &Spanned<&'s str>) -> ParamIter<'s, 'a, 'c> {
+        ParamIter {
+            ctxt: self.ctxt,
+            span: from.span,
+            string: from.node
+        }
+    }
+}
+
+impl<'s, 'a, 'c> Iterator for ParamIter<'s, 'a, 'c> {
+    type Item = Spanned<&'s str>;
+
+    fn next(&mut self) -> Option<Spanned<&'s str>> {
+        // Find the start and end indexes for the next parameter, if any.
+        let (start, end) = match (self.string.find('<'), self.string.find('>')) {
+            (Some(i), Some(j)) => (i, j),
+            _ => return None
+        };
+
+        // Ensure we found a valid parameter.
+        if end <= start {
+            self.ctxt.span_err(self.span, "Parameter list is malformed.");
+            return None;
+        }
+
+        // Calculate the parameter and the span for the parameter.
+        let param = &self.string[(start + 1)..end];
+        let mut param_span = self.span;
+        param_span.lo = self.span.lo + BytePos(start as u32);
+        param_span.hi = self.span.lo + BytePos((end + 1) as u32);
+
+        // Check for nonemptiness and that the characters are correct.
+        if param.len() == 0 {
+            self.ctxt.span_err(param_span, "Parameter names cannot be empty.");
+            None
+        } else if param.contains(|c: char| !c.is_alphanumeric()) {
+            self.ctxt.span_err(param_span, "Parameters must be alphanumeric.");
+            None
+        } else {
+            self.string = &self.string[(end + 1)..];
+            self.span.lo = self.span.lo + BytePos((end + 1) as u32);
+            Some(span(param, param_span))
+        }
+    }
+}
+
+pub struct RouteParams {
+    pub method: Spanned<Method>,
+    pub path: KVSpanned<String>,
+    pub form: Option<KVSpanned<String>>,
+}
+
+pub trait RouteDecoratorExt {
+    fn bad_method(&self, sp: Span, message: &str);
+    fn parse_method(&self, default: Method) -> Spanned<Method>;
+    fn parse_route(&self, known_method: Option<Spanned<Method>>) -> RouteParams;
+}
+
+impl<'a, 'c> RouteDecoratorExt for MetaItemParser<'a, 'c> {
+    fn bad_method(&self, sp: Span, message: &str) {
+        let message = format!("{} Valid methods are: [GET, PUT, POST, DELETE, \
+            OPTIONS, HEAD, TRACE, CONNECT, PATCH]", message);
+        self.ctxt.span_err(sp, message.as_str());
+    }
+
+    fn parse_method(&self, default: Method) -> Spanned<Method> {
+        let params = self.expect_list();
+        if params.len() < 1 {
+            self.bad_method(self.span, "HTTP method parameter is missing.");
+            self.ctxt.span_fatal(self.span, "At least 2 arguments are required.");
+        }
+
+        // Get the method and the rest of the k = v params.
+        let method_param = params.first().unwrap();
+
+        // Check that the method parameter is a word (i.e, not a list, k/v pair).
+        if !method_param.is_word() {
+            self.bad_method(method_param.span,
+                "Expected a valid HTTP method at this position.");
+            return dummy_span(default);
+        }
+
+        // Parse the method from the string. If bad, error and return default.
+        Method::from_str(method_param.name()).ok().map_or_else(|| {
+            let message = format!("{} is not a valid method.", method_param.name());
+            self.bad_method(method_param.span, message.as_str());
+            dummy_span(default)
+        }, |method| span(method, method_param.span))
+    }
+
+    // Parses the MetaItem derived from the route(...) macro.
+   fn parse_route(&self, known_method: Option<Spanned<Method>>) -> RouteParams {
+        let list = self.expect_list();
+        let (method, kv_params) = match known_method {
+            Some(method) => (method, &list[..]),
+            None => (self.parse_method(Method::Get), list.split_first().unwrap().1)
+        };
+
+        // Now grab all of the required and optional parameters.
+        let req: [&'static str; 1] = ["path"];
+        let opt: [&'static str; 1] = ["form"];
+        let kv_pairs = get_key_values(self.ctxt, self.meta_item.span,
+                                      &req, &opt, kv_params);
+
+        // Ensure we have a path, just to keep parsing and generating errors.
+        let path = kv_pairs.get("path").map_or(KVSpanned::dummy("/".to_string()), |s| {
+            s.clone().map(String::from)
+        });
+
+        // If there's a form parameter, ensure method is POST.
+        let form = kv_pairs.get("form").map_or(None, |f| {
+            if method.node != Method::Post {
+                self.ctxt.span_err(f.p_span, "Use of `form` requires POST method...");
+                let message = format!("...but {} was found instead.", method.node);
+                self.ctxt.span_err(method.span, message.as_str());
+            }
+
+            if !(f.node.starts_with('<') && f.node.ends_with('>')) {
+                self.ctxt.struct_span_err(f.p_span,
+                                        "`form` cannot contain arbitrary text")
+                    .help("`form` must be exactly one parameter: \"<param>\"")
+                    .emit();
+            }
+
+            if f.node.chars().filter(|c| *c == '<' || *c == '>').count() != 2 {
+                self.ctxt.span_err(f.p_span,
+                                   "`form` must contain exactly one parameter");
+            }
+
+            Some(f.clone().map(String::from))
+        });
+
+        RouteParams {
+            method: method,
+            path: path,
+            form: form
+        }
+    }
+
+}

macros/src/route_decorator.rs

@@ -1,11 +1,11 @@
 use super::{ROUTE_STRUCT_PREFIX, ROUTE_FN_PREFIX};
 use utils::*;
+use meta_item_parser::{MetaItemParser, RouteDecoratorExt};
 
-use std::str::FromStr;
 use std::collections::HashMap;
 
 use syntax::codemap::{Span, BytePos, /* DUMMY_SP, */ Spanned};
-use syntax::ast::{Stmt, Item, Expr, ItemKind, MetaItem, MetaItemKind, FnDecl};
+use syntax::ast::{Stmt, Expr, MetaItem, FnDecl};
 use syntax::ext::base::{Annotatable, ExtCtxt};
 use syntax::ptr::P;
 use syntax::print::pprust::{item_to_string, stmt_to_string};
@@ -16,156 +16,16 @@ use rocket::Method;
 #[allow(dead_code)]
 const DEBUG: bool = true;
 
-struct Params {
-    method: Spanned<Method>,
-    path: KVSpanned<String>,
-    form: Option<KVSpanned<String>>,
-}
-
-fn bad_item_fatal(ecx: &mut ExtCtxt, dec_sp: Span, i_sp: Span) -> ! {
-    ecx.span_err(dec_sp, "This decorator cannot be used on non-functions...");
-    ecx.span_fatal(i_sp, "...but it was used on the item below.")
-}
-
-fn bad_method_err(ecx: &mut ExtCtxt, dec_sp: Span, message: &str) -> Method {
-    let message = format!("{} Valid methods are: [GET, PUT, POST, DELETE, \
-        OPTIONS, HEAD, TRACE, CONNECT, PATCH]", message);
-    ecx.span_err(dec_sp, message.as_str());
-    Method::Get
-}
-
-pub fn get_fn_decl<'a>(ecx: &mut ExtCtxt, sp: Span, annotated: &'a Annotatable)
-        -> (&'a P<Item>, Spanned<&'a FnDecl>) {
-    // `annotated` is the AST object for the annotated item.
-    let item: &P<Item> = match *annotated {
-        Annotatable::Item(ref item) => item,
-        Annotatable::TraitItem(ref item) => bad_item_fatal(ecx, sp, item.span),
-        Annotatable::ImplItem(ref item) => bad_item_fatal(ecx, sp, item.span)
-    };
-
-    let fn_decl: &P<FnDecl> = match item.node {
-         ItemKind::Fn(ref decl, _, _, _, _, _) => decl,
-         _ => bad_item_fatal(ecx, sp, item.span)
-     };
-
-    (item, wrap_span(&*fn_decl, item.span))
-}
-
-// Parses the MetaItem derived from the route(...) macro.
-fn parse_route(ecx: &mut ExtCtxt, meta_item: &MetaItem) -> Params {
-    // Ensure we've been supplied with a k = v meta item. Error out if not.
-    let params = meta_item.expect_list(ecx, "Bad use. Expected: #[route(...)]");
-    if params.len() < 1 {
-        bad_method_err(ecx, meta_item.span, "HTTP method parameter is missing.");
-        ecx.span_fatal(meta_item.span, "At least 2 arguments are required.");
-    }
-
-    // Get the method and the rest of the k = v params.
-    let (method_param, kv_params) = params.split_first().unwrap();
-
-    // Ensure method parameter is valid. If it's not, issue an error but use
-    // "GET" to continue parsing. method :: Spanned<Method>.
-    let method = if let MetaItemKind::Word(ref word) = method_param.node {
-        let method = Method::from_str(word).unwrap_or_else(|_| {
-            let message = format!("{} is not a valid method.", word);
-            bad_method_err(ecx, method_param.span, message.as_str())
-        });
-
-        Spanned { span: method_param.span, node: method }
-    } else {
-        let method = bad_method_err(ecx, method_param.span, "Invalid parameter. \
-            Expected a valid HTTP method at this position.");
-        dummy_span(method)
-    };
-
-    // Now grab all of the required and optional parameters.
-    let req: [&'static str; 1] = ["path"];
-    let opt: [&'static str; 1] = ["form"];
-    let kv_pairs = get_key_values(ecx, meta_item.span, &req, &opt, kv_params);
-
-    // Ensure we have a path, just to keep parsing and generating errors.
-    let path = kv_pairs.get("path").map_or(KVSpanned::dummy("/".to_string()), |s| {
-        s.clone().map(String::from)
-    });
-
-    // If there's a form parameter, ensure method is POST.
-    let form = kv_pairs.get("form").map_or(None, |f| {
-        if method.node != Method::Post {
-            ecx.span_err(f.p_span, "Use of `form` requires a POST method...");
-            let message = format!("...but {} was found instead.", method.node);
-            ecx.span_err(method_param.span, message.as_str());
-        }
-
-        if !(f.node.starts_with('<') && f.node.ends_with('>')) {
-            ecx.struct_span_err(f.p_span, "`form` cannot contain arbitrary text")
-                .help("`form` must be exactly one parameter: \"<param>\"")
-                .emit();
-        }
-
-        if f.node.chars().filter(|c| *c == '<' || *c == '>').count() != 2 {
-            ecx.span_err(f.p_span, "`form` must contain exactly one parameter");
-        }
-
-        Some(f.clone().map(String::from))
-    });
-
-    Params {
-        method: method,
-        path: path,
-        form: form
-    }
-}
-
-// TODO: Put something like this in the library. Maybe as an iterator?
-pub fn extract_params<'a>(ecx: &ExtCtxt, params: &Spanned<&'a str>)
-        -> Vec<Spanned<&'a str>> {
-    let mut output_params = vec![];
-    let bad_match_err = "Parameter string is malformed.";
-
-    let mut start = 0;
-    let mut matching = false;
-    for (i, c) in params.node.char_indices() {
-        match c {
-            '<' if !matching => {
-                matching = true;
-                start = i;
-            },
-            '>' if matching => {
-                matching = false;
-
-                let mut param_span = params.span;
-                param_span.lo = params.span.lo + BytePos(start as u32);
-                param_span.hi = params.span.lo + BytePos((i + 1) as u32);
-
-                if i > start + 1 {
-                    let param_name = &params.node[(start + 1)..i];
-                    output_params.push(wrap_span(param_name, param_span))
-                } else {
-                    ecx.span_err(param_span, "Parameter names cannot be empty.");
-                }
-            },
-            '<' if matching => ecx.span_err(params.span, bad_match_err),
-            '>' if !matching => ecx.span_err(params.span, bad_match_err),
-            _ => { /* ... */ }
-        }
-    }
-
-    output_params
-}
-
-pub fn extract_params_from_kv<'a>(ecx: &ExtCtxt, params: &'a KVSpanned<String>)
-        -> Vec<Spanned<&'a str>> {
+pub fn extract_params_from_kv<'a>(parser: &MetaItemParser,
+                    params: &'a KVSpanned<String>) -> Vec<Spanned<&'a str>> {
     let mut param_span = params.v_span;
     param_span.lo = params.v_span.lo + BytePos(1);
-    extract_params(ecx, &Spanned {
-        span: param_span,
-        node: &*params.node
-    })
+    let spanned = span(&*params.node, param_span);
+    parser.iter_params(&spanned).collect()
 }
 
 // Analyzes the declared parameters against the function declaration. Returns
-// two vectors. The first is the set of parameters declared by the user, and
-// the second is the set of parameters not declared by the user.
+// a vector of all of the parameters in the order the user wants them.
 fn get_fn_params<'a, T: Iterator<Item=&'a Spanned<&'a str>>>(ecx: &ExtCtxt,
         declared_params: T, fn_decl: &Spanned<&FnDecl>)
             -> Vec<UserParam> {
@@ -273,15 +133,16 @@ fn method_variant_to_expr(ecx: &ExtCtxt, method: Method) -> P<Expr> {
 pub fn route_decorator(ecx: &mut ExtCtxt, sp: Span, meta_item: &MetaItem,
           annotated: &Annotatable, push: &mut FnMut(Annotatable)) {
     // Get the encompassing item and function declaration for the annotated func.
-    let (item, fn_decl) = get_fn_decl(ecx, sp, annotated);
+    let parser = MetaItemParser::new(ecx, meta_item, annotated, &sp);
+    let (item, fn_decl) = (parser.expect_item(), parser.expect_fn_decl());
 
     // Parse and retrieve all of the parameters of the route.
-    let route = parse_route(ecx, meta_item);
+    let route = parser.parse_route(None);
 
     // Get a list of the user declared parameters in `path` and `form`.
-    let path_params = extract_params_from_kv(ecx, &route.path);
+    let path_params = extract_params_from_kv(&parser, &route.path);
     let form_thing = route.form.unwrap_or_default(); // Default is empty string.
-    let form_params = extract_params_from_kv(ecx, &form_thing);
+    let form_params = extract_params_from_kv(&parser, &form_thing);
 
     // Ensure the params match the function declaration and return the params.
     let all_params = path_params.iter().chain(form_params.iter());

macros/src/routes_macro.rs

@@ -23,7 +23,7 @@ pub fn routes_macro(ecx: &mut ExtCtxt, _sp: Span, args: &[TokenTree])
 
     // Build up the P<Expr> for each path.
     let path_exprs: Vec<P<Expr>> = paths.iter().map(|p| {
-        quote_expr!(ecx, rocket::Route::from(&$p))
+        quote_expr!(ecx, ::rocket::Route::from(&$p))
     }).collect();
 
     // Now put them all in one vector and return the thing.

macros/src/utils.rs

@@ -37,7 +37,7 @@ pub fn append_ident<T: ToString>(ident: &Ident, other: T) -> Ident {
 }
 
 #[inline]
-pub fn wrap_span<T>(t: T, span: Span) -> Spanned<T> {
+pub fn span<T>(t: T, span: Span) -> Spanned<T> {
     Spanned {
         span: span,
         node: t,
@@ -95,7 +95,7 @@ impl<T> KVSpanned<T> {
     }
 }
 
-pub fn get_key_values<'b>(ecx: &mut ExtCtxt, sp: Span, required: &[&str],
+pub fn get_key_values<'b>(ecx: &ExtCtxt, sp: Span, required: &[&str],
         optional: &[&str], kv_params: &'b [P<MetaItem>])
             -> HashMap<&'b str, KVSpanned<&'b str>> {
     let mut seen = HashSet::new();
@@ -160,9 +160,21 @@ pub fn token_separate<T: ToTokens>(ecx: &ExtCtxt, things: &[T],
 pub trait MetaItemExt {
     fn expect_list<'a>(&'a self, ecx: &ExtCtxt, msg: &str) -> &'a Vec<P<MetaItem>>;
     fn expect_word<'a>(&'a self, ecx: &ExtCtxt, msg: &str) -> &'a str;
+    fn is_word(&self) -> bool;
+    fn name<'a>(&'a self) -> &'a str;
 }
 
 impl MetaItemExt for MetaItem {
+    fn name<'a>(&'a self) -> &'a str {
+        let interned_name = match self.node {
+            MetaItemKind::Word(ref s) => s,
+            MetaItemKind::List(ref s, _) => s,
+            MetaItemKind::NameValue(ref s, _) => s
+        };
+
+        &*interned_name
+    }
+
     fn expect_list<'a>(&'a self, ecx: &ExtCtxt, msg: &str) -> &'a Vec<P<MetaItem>> {
         match self.node {
             MetaItemKind::List(_, ref params) => params,
@@ -176,6 +188,13 @@ impl MetaItemExt for MetaItem {
             _ => ecx.span_fatal(self.span, msg)
         }
     }
+
+    fn is_word(&self) -> bool {
+        match self.node {
+            MetaItemKind::Word(_) => true,
+            _ => false
+        }
+    }
 }
 
 pub trait PatExt {