back to enums

1 files changed, 62 insertions, 24 deletions

diff --git a/src/libzisp/io/Parser.zig b/src/libzisp/io/Parser.zig
index 7264eaa..6684104 100644
--- a/src/libzisp/io/Parser.zig
+++ b/src/libzisp/io/Parser.zig
@@ -108,8 +108,6 @@ pub const ParseError = enum {
     ReadError,
 };
 
-const Fn = *const fn (*Parser) anyerror!void;
-
 pub const Context = struct {
     // What to do next.
     next: ?Fn = undefined,
@@ -219,12 +217,52 @@ fn getRune(p: *Parser) Value {
 // Stack management & control flow
 //
 
+const Fn = enum {
+    parseUnit,
+    parseDatum,
+    endUnit,
+    returnContext,
+    endFirstDatum,
+    endJoinDatum,
+    parseJoin,
+    parseHashDatum,
+    endHashDatum,
+    parseRuneDatum,
+    endRuneDatum,
+    endLabelDatum,
+    continueList,
+    endImproperList,
+    closeImproperList,
+    endQuoteExpr,
+};
+
+fn call(p: *Parser, f: Fn) !void {
+    try switch (f) {
+        .parseUnit => parseUnit(p),
+        .parseDatum => parseDatum(p),
+        .endUnit => endUnit(p),
+        .returnContext => returnContext(p),
+        .endFirstDatum => endFirstDatum(p),
+        .endJoinDatum => endJoinDatum(p),
+        .parseJoin => parseJoin(p),
+        .parseHashDatum => parseHashDatum(p),
+        .endHashDatum => endHashDatum(p),
+        .parseRuneDatum => parseRuneDatum(p),
+        .endRuneDatum => endRuneDatum(p),
+        .endLabelDatum => endLabelDatum(p),
+        .continueList => continueList(p),
+        .endImproperList => endImproperList(p),
+        .closeImproperList => closeImproperList(p),
+        .endQuoteExpr => endQuoteExpr(p),
+    };
+}
+
 pub fn run(p: *Parser, input: std.io.AnyReader) !Value {
     p.input = input;
-    p.context.next = &parseUnit;
+    p.context.next = .parseUnit;
     while (p.context.next) |next| {
         if (detailed_debug) printStack(p);
-        try next(p);
+        try p.call(next);
     }
     if (p.unread_char) |_| {
         return p.err(.InvalidCharacter, "top-level");
@@ -312,10 +350,10 @@ fn parseUnit(p: *Parser) !void {
     while (c1) |c| : (c1 = try p.read()) {
         switch (try checkBlanks(p, c)) {
             .yes => {},
-            .skip_unit => try p.push(&parseUnit),
+            .skip_unit => try p.push(.parseUnit),
             .no => {
                 p.unread(c);
-                return p.subr(&parseDatum, &endUnit);
+                return p.subr(.parseDatum, .endUnit);
             },
         }
     }
@@ -334,7 +372,7 @@ fn endUnit(p: *Parser) !void {
 
 fn skipUnitAndReturn(p: *Parser) !void {
     p.context.val = p.result;
-    return p.subr(&parseUnit, &returnContext);
+    return p.subr(.parseUnit, .returnContext);
 }
 
 fn returnContext(p: *Parser) !void {
@@ -342,7 +380,7 @@ fn returnContext(p: *Parser) !void {
 }
 
 fn parseDatum(p: *Parser) !void {
-    return parseOneDatum(p, p.getUnread().?, &endFirstDatum);
+    return parseOneDatum(p, p.getUnread().?, .endFirstDatum);
 }
 
 fn endFirstDatum(p: *Parser) !void {
@@ -365,7 +403,7 @@ fn parseJoin(p: *Parser) !void {
         },
     }
     p.context.val = p.result;
-    return p.subr(&parseDatum, &endJoinDatum);
+    return p.subr(.parseDatum, .endJoinDatum);
 }
 
 fn endJoinDatum(p: *Parser) !void {
@@ -385,7 +423,7 @@ fn endJoinDatum(p: *Parser) !void {
         else => unreachable,
     };
     const joined = p.cons(rune, p.cons(prev, p.result));
-    return p.jump(&parseJoin, joined);
+    return p.jump(.parseJoin, joined);
 }
 
 fn parseOneDatum(p: *Parser, c: u8, next: Fn) !void {
@@ -544,11 +582,11 @@ fn parseHashExpression(p: *Parser, next: Fn) !void {
         return p.jump(next, p.cons(HASH, try parseQuotedString(p, '|')));
     }
     p.unread(c);
-    return p.subr(&parseHashDatum, next);
+    return p.subr(.parseHashDatum, next);
 }
 
 fn parseHashDatum(p: *Parser) !void {
-    return parseCladDatum(p, p.getUnread().?, &endHashDatum);
+    return parseCladDatum(p, p.getUnread().?, .endHashDatum);
 }
 
 fn endHashDatum(p: *Parser) !void {
@@ -588,14 +626,14 @@ fn parseRuneEnd(p: *Parser, r: Value, next: Fn) !void {
             try p.push(next);
             p.context.val = r;
             // Use jump to prevent recursion.
-            return p.jump(&parseRuneDatum, null);
+            return p.jump(.parseRuneDatum, null);
         },
         else => return p.jump(next, r),
     }
 }
 
 fn parseRuneDatum(p: *Parser) !void {
-    return parseCladDatum(p, p.getUnread().?, &endRuneDatum);
+    return parseCladDatum(p, p.getUnread().?, .endRuneDatum);
 }
 
 fn endRuneDatum(p: *Parser) !void {
@@ -618,7 +656,7 @@ fn parseLabelEnd(p: *Parser, l: Value, next: Fn) !void {
     if (c == '=') {
         try p.push(next);
         p.context.val = l;
-        return p.subr(&parseDatum, &endLabelDatum);
+        return p.subr(.parseDatum, .endLabelDatum);
     }
     return p.err(.InvalidCharacter, "datum label");
 }
@@ -651,12 +689,12 @@ fn parseList(p: *Parser, open: u8, next: Fn) !void {
             .yes => {},
             .skip_unit => {
                 try listParserSetup(p, head, close, next);
-                return p.subr(&parseUnit, &parseUnit);
+                return p.subr(.parseUnit, .parseUnit);
             },
             .no => {
                 try listParserSetup(p, head, close, next);
                 p.unread(c);
-                return p.jump(&parseDatum, null);
+                return p.jump(.parseDatum, null);
             },
         }
     }
@@ -667,7 +705,7 @@ fn listParserSetup(p: *Parser, head: Value, close: u8, next: Fn) !void {
     try p.push(next);
     p.context.val = head;
     p.context.char = close;
-    try p.pushContext(&continueList);
+    try p.pushContext(.continueList);
 }
 
 fn continueList(p: *Parser) !void {
@@ -682,7 +720,7 @@ fn continueList(p: *Parser) !void {
     }
 
     if (p.result.eq(LSTAIL)) {
-        return p.subr(&parseUnit, &endImproperList);
+        return p.subr(.parseUnit, .endImproperList);
     }
 
     p.context.val = p.cons(p.result, p.context.val);
@@ -695,12 +733,12 @@ fn continueList(p: *Parser) !void {
         switch (try checkBlanks(p, c)) {
             .yes => {},
             .skip_unit => {
-                try p.pushContext(&continueList);
-                return p.subr(&parseUnit, &parseUnit);
+                try p.pushContext(.continueList);
+                return p.subr(.parseUnit, .parseUnit);
             },
             .no => {
                 p.unread(c);
-                return p.subr(&parseDatum, &continueList);
+                return p.subr(.parseDatum, .continueList);
             },
         }
     }
@@ -729,7 +767,7 @@ fn closeImproperList(p: *Parser) !void {
         }
         switch (try checkBlanks(p, c)) {
             .yes => {},
-            .skip_unit => return p.subr(&parseUnit, &closeImproperList),
+            .skip_unit => return p.subr(.parseUnit, .closeImproperList),
             .no => return p.err(.InvalidCharacter, "after list tail"),
         }
     }
@@ -753,7 +791,7 @@ fn parseQuoteExpr(p: *Parser, c1: u8, next: Fn) !void {
     try p.push(next);
     p.context.val = q;
     p.unread(c);
-    return p.subr(&parseDatum, &endQuoteExpr);
+    return p.subr(.parseDatum, .endQuoteExpr);
 }
 
 fn endQuoteExpr(p: *Parser) !void {