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tagged literals for edn reader, new sigs for read-edn, read-edn-string
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@richhickey
richhickey committed Feb 7, 2013
1 parent 19f1e49 commit 692817a
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Showing 3 changed files with 114 additions and 47 deletions.
47 changes: 28 additions & 19 deletions src/clj/clojure/core.clj
View file
Expand Up @@ -3406,23 +3406,6 @@
([stream eof-error? eof-value recursive?]
(. clojure.lang.LispReader (read stream (boolean eof-error?) eof-value recursive?))))

(defn read-edn
"Reads the next object from stream, which must be an instance of
java.io.PushbackReader or some derivee. stream defaults to the
current value of *in*.
Reads data in the edn format (subset of Clojure data):
http://edn-format.org"
{:added "1.5"}
([]
(read-edn *in*))
([stream]
(read-edn stream true nil))
([stream eof-error? eof-value]
(read-edn stream eof-error? eof-value false))
([stream eof-error? eof-value recursive?]
(. clojure.lang.EdnReader (read stream (boolean eof-error?) eof-value recursive?))))

(defn read-line
"Reads the next line from stream that is the current value of *in* ."
{:added "1.0"
Expand All @@ -3443,13 +3426,39 @@
:static true}
[s] (clojure.lang.RT/readString s))

(defn read-edn
"Reads the next object from stream, which must be an instance of
java.io.PushbackReader or some derivee. stream defaults to the
current value of *in*.
Reads data in the edn format (subset of Clojure data):
http://edn-format.org
opts is a map that can include the following keys:
:eof - value to return on end-of-file. When not supplied, eof throws an exception.
:readers - a map of tag symbols to data-reader functions to be considered before *default-data-readers*.
When not supplied, only the *default-data-readers* will be used.
:default - A function of two args, that will, if present and no reader is found for a tag,
be called with the tag and the value."

{:added "1.5"}
([]
(read-edn *in*))
([stream]
(read-edn {} stream))
([opts stream]
(clojure.lang.EdnReader/read stream opts)))

(defn read-edn-string
"Reads one object from the string s. Returns nil when s is nil or empty.
Reads data in the edn format (subset of Clojure data):
http://edn-format.org"
http://edn-format.org
opts is a map as per read-edn"
{:added "1.5"}
[s] (when (pos? (count s)) (clojure.lang.EdnReader/readString s)))
([s] (read-edn-string {:eof nil} s))
([opts s] (when s (clojure.lang.EdnReader/readString s opts))))

(defn subvec
"Returns a persistent vector of the items in vector from
Expand Down
112 changes: 85 additions & 27 deletions src/jvm/clojure/lang/EdnReader.java
View file
Expand Up @@ -32,6 +32,8 @@ public class EdnReader{
static Pattern floatPat = Pattern.compile("([-+]?[0-9]+(\\.[0-9]*)?([eE][-+]?[0-9]+)?)(M)?");
static final Symbol SLASH = Symbol.intern("/");

static IFn taggedReader = new TaggedReader();

static
{
macros['"'] = new StringReader();
Expand All @@ -54,10 +56,14 @@ public class EdnReader{
dispatchMacros['_'] = new DiscardReader();
}

static public Object readString(String s){
static boolean nonConstituent(int ch){
return ch == '@' || ch == '`' || ch == '~';
}

static public Object readString(String s, IPersistentMap opts){
PushbackReader r = new PushbackReader(new java.io.StringReader(s));
try {
return EdnReader.read(r, true, null, false);
return read(r, opts);
}
catch(Exception e) {
throw Util.sneakyThrow(e);
Expand Down Expand Up @@ -102,7 +108,14 @@ static public int read1(Reader r){
}
}

static public Object read(PushbackReader r, boolean eofIsError, Object eofValue, boolean isRecursive)
static final Keyword EOF = Keyword.intern(null,"eof");

static public Object read(PushbackReader r, IPersistentMap opts){
return read(r,!opts.containsKey(EOF),opts.valAt(EOF),false,opts);
}

static public Object read(PushbackReader r, boolean eofIsError, Object eofValue, boolean isRecursive,
Object opts)
{

try
Expand Down Expand Up @@ -132,7 +145,7 @@ static public Object read(PushbackReader r, boolean eofIsError, Object eofValue,
IFn macroFn = getMacro(ch);
if(macroFn != null)
{
Object ret = macroFn.invoke(r, (char) ch);
Object ret = macroFn.invoke(r, (char) ch, opts);
if(RT.suppressRead())
return null;
//no op macros return the reader
Expand Down Expand Up @@ -173,16 +186,22 @@ static public Object read(PushbackReader r, boolean eofIsError, Object eofValue,

static private String readToken(PushbackReader r, char initch) {
StringBuilder sb = new StringBuilder();
if(nonConstituent(initch))
throw Util.runtimeException("Invalid leading character: " + (char)initch);

sb.append(initch);

for(; ;)
{
int ch = read1(r);

if(ch == -1 || isWhitespace(ch) || isTerminatingMacro(ch))
{
unread(r, ch);
return sb.toString();
}
else if(nonConstituent(ch))
throw Util.runtimeException("Invalid constituent character: " + (char)ch);
sb.append((char) ch);
}
}
Expand Down Expand Up @@ -391,7 +410,7 @@ public Object invoke(Object reader, Object doublequote) {
*/

public static class StringReader extends AFn{
public Object invoke(Object reader, Object doublequote) {
public Object invoke(Object reader, Object doublequote, Object opts) {
StringBuilder sb = new StringBuilder();
Reader r = (Reader) reader;

Expand Down Expand Up @@ -453,7 +472,7 @@ public Object invoke(Object reader, Object doublequote) {
}

public static class CommentReader extends AFn{
public Object invoke(Object reader, Object semicolon) {
public Object invoke(Object reader, Object semicolon, Object opts) {
Reader r = (Reader) reader;
int ch;
do
Expand All @@ -466,29 +485,36 @@ public Object invoke(Object reader, Object semicolon) {
}

public static class DiscardReader extends AFn{
public Object invoke(Object reader, Object underscore) {
public Object invoke(Object reader, Object underscore, Object opts) {
PushbackReader r = (PushbackReader) reader;
read(r, true, null, true);
read(r, true, null, true, opts);
return r;
}
}

public static class DispatchReader extends AFn{
public Object invoke(Object reader, Object hash) {
public Object invoke(Object reader, Object hash, Object opts) {
int ch = read1((Reader) reader);
if(ch == -1)
throw Util.runtimeException("EOF while reading character");
IFn fn = dispatchMacros[ch];

if(fn == null) {
//try tagged reader
if(Character.isLetter(ch))
{
unread((PushbackReader) reader, ch);
return taggedReader.invoke(reader, ch, opts);
}

throw Util.runtimeException(String.format("No dispatch macro for: %c", (char) ch));
}
return fn.invoke(reader, ch);
return fn.invoke(reader, ch, opts);
}
}

public static class MetaReader extends AFn{
public Object invoke(Object reader, Object caret) {
public Object invoke(Object reader, Object caret, Object opts) {
PushbackReader r = (PushbackReader) reader;
int line = -1;
int column = -1;
Expand All @@ -497,15 +523,15 @@ public Object invoke(Object reader, Object caret) {
line = ((LineNumberingPushbackReader) r).getLineNumber();
column = ((LineNumberingPushbackReader) r).getColumnNumber()-1;
}
Object meta = read(r, true, null, true);
Object meta = read(r, true, null, true, opts);
if(meta instanceof Symbol || meta instanceof String)
meta = RT.map(RT.TAG_KEY, meta);
else if (meta instanceof Keyword)
meta = RT.map(meta, RT.T);
else if(!(meta instanceof IPersistentMap))
throw new IllegalArgumentException("Metadata must be Symbol,Keyword,String or Map");

Object o = read(r, true, null, true);
Object o = read(r, true, null, true, opts);
if(o instanceof IMeta)
{
if(line != -1 && o instanceof ISeq)
Expand All @@ -531,7 +557,7 @@ else if(!(meta instanceof IPersistentMap))
}

public static class CharacterReader extends AFn{
public Object invoke(Object reader, Object backslash) {
public Object invoke(Object reader, Object backslash, Object opts) {
PushbackReader r = (PushbackReader) reader;
int ch = read1(r);
if(ch == -1)
Expand Down Expand Up @@ -574,7 +600,7 @@ else if(token.startsWith("o"))
}

public static class ListReader extends AFn{
public Object invoke(Object reader, Object leftparen) {
public Object invoke(Object reader, Object leftparen, Object opts) {
PushbackReader r = (PushbackReader) reader;
int line = -1;
int column = -1;
Expand All @@ -583,7 +609,7 @@ public Object invoke(Object reader, Object leftparen) {
line = ((LineNumberingPushbackReader) r).getLineNumber();
column = ((LineNumberingPushbackReader) r).getColumnNumber()-1;
}
List list = readDelimitedList(')', r, true);
List list = readDelimitedList(')', r, true, opts);
if(list.isEmpty())
return PersistentList.EMPTY;
IObj s = (IObj) PersistentList.create(list);
Expand All @@ -599,17 +625,17 @@ public Object invoke(Object reader, Object leftparen) {
}

public static class VectorReader extends AFn{
public Object invoke(Object reader, Object leftparen) {
public Object invoke(Object reader, Object leftparen, Object opts) {
PushbackReader r = (PushbackReader) reader;
return LazilyPersistentVector.create(readDelimitedList(']', r, true));
return LazilyPersistentVector.create(readDelimitedList(']', r, true, opts));
}

}

public static class MapReader extends AFn{
public Object invoke(Object reader, Object leftparen) {
public Object invoke(Object reader, Object leftparen, Object opts) {
PushbackReader r = (PushbackReader) reader;
Object[] a = readDelimitedList('}', r, true).toArray();
Object[] a = readDelimitedList('}', r, true, opts).toArray();
if((a.length & 1) == 1)
throw Util.runtimeException("Map literal must contain an even number of forms");
return RT.map(a);
Expand All @@ -618,27 +644,27 @@ public Object invoke(Object reader, Object leftparen) {
}

public static class SetReader extends AFn{
public Object invoke(Object reader, Object leftbracket) {
public Object invoke(Object reader, Object leftbracket, Object opts) {
PushbackReader r = (PushbackReader) reader;
return PersistentHashSet.createWithCheck(readDelimitedList('}', r, true));
return PersistentHashSet.createWithCheck(readDelimitedList('}', r, true, opts));
}

}

public static class UnmatchedDelimiterReader extends AFn{
public Object invoke(Object reader, Object rightdelim) {
public Object invoke(Object reader, Object rightdelim, Object opts) {
throw Util.runtimeException("Unmatched delimiter: " + rightdelim);
}

}

public static class UnreadableReader extends AFn{
public Object invoke(Object reader, Object leftangle) {
public Object invoke(Object reader, Object leftangle, Object opts) {
throw Util.runtimeException("Unreadable form");
}
}

public static List readDelimitedList(char delim, PushbackReader r, boolean isRecursive) {
public static List readDelimitedList(char delim, PushbackReader r, boolean isRecursive, Object opts) {
final int firstline =
(r instanceof LineNumberingPushbackReader) ?
((LineNumberingPushbackReader) r).getLineNumber() : -1;
Expand Down Expand Up @@ -666,7 +692,7 @@ public static List readDelimitedList(char delim, PushbackReader r, boolean isRec
IFn macroFn = getMacro(ch);
if(macroFn != null)
{
Object mret = macroFn.invoke(r, (char) ch);
Object mret = macroFn.invoke(r, (char) ch, opts);
//no op macros return the reader
if(mret != r)
a.add(mret);
Expand All @@ -675,7 +701,7 @@ public static List readDelimitedList(char delim, PushbackReader r, boolean isRec
{
unread(r, ch);

Object o = read(r, true, null, isRecursive);
Object o = read(r, true, null, isRecursive, opts);
if(o != r)
a.add(o);
}
Expand All @@ -685,5 +711,37 @@ public static List readDelimitedList(char delim, PushbackReader r, boolean isRec
return a;
}

public static class TaggedReader extends AFn{
public Object invoke(Object reader, Object firstChar, Object opts){
PushbackReader r = (PushbackReader) reader;
Object name = read(r, true, null, false, opts);
if (!(name instanceof Symbol))
throw new RuntimeException("Reader tag must be a symbol");
Symbol sym = (Symbol)name;
return readTagged(r, sym, (IPersistentMap) opts);
}

static Keyword READERS = Keyword.intern(null,"readers");
static Keyword DEFAULT = Keyword.intern(null,"default");

private Object readTagged(PushbackReader reader, Symbol tag, IPersistentMap opts){
Object o = read(reader, true, null, true, opts);

ILookup readers = (ILookup)RT.get(opts, READERS);
IFn dataReader = (IFn)RT.get(readers, tag);
if(dataReader == null)
dataReader = (IFn)RT.get(RT.DEFAULT_DATA_READERS.deref(),tag);
if(dataReader == null){
IFn defaultReader = (IFn)RT.get(opts, DEFAULT);
if(defaultReader != null)
return defaultReader.invoke(tag, o);
else
throw new RuntimeException("No reader function for tag " + tag.toString());
}
else
return dataReader.invoke(o);
}

}
}

2 changes: 1 addition & 1 deletion src/jvm/clojure/lang/LispReader.java
View file
Expand Up @@ -424,7 +424,7 @@ static private boolean isMacro(int ch){
}

static private boolean isTerminatingMacro(int ch){
return (ch != '#' && ch != '\'' && isMacro(ch));
return (ch != '#' && ch != '\'' && ch != '%' && isMacro(ch));
}

public static class RegexReader extends AFn{
Expand Down

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