lex: tokstr now prints escaped strings

this should be the final thing to make [[tokstr]] print syntactically-valid
tokens in all cases

Makefile

@@ -7,7 +7,8 @@ HARESRCDIR=${SRCDIR}/hare
 HARE=hare
 HAREPATH=vendor/hare-unicode:${HARESRCDIR}/stdlib:${HARESRCDIR}/third-party
 
-.PHONY: check build clean
+.PHONY: check build clean print-harepath
+
 
 check:
 	@env HAREPATH=${HAREPATH} hare test -T +test
@@ -17,3 +18,6 @@ build:
 
 clean:
 	rm -f kj
+
+print-harepath:
+	@echo ${HAREPATH}

kojote/lex/+test.ha

@@ -28,11 +28,12 @@ type dummytoken = (ty, value);
 				(ty::BOOLEAN, true),
 				(ty::BOOLEAN, false),
 			]),
-		(`#\a #\space #\nul`,
+		(`#\a #\space #\nul #\嶲`,
 			[
 				(ty::CHAR, 'a'),
 				(ty::CHAR, ' '),
 				(ty::CHAR, '\0'),
+				(ty::CHAR, '嶲'),
 			]),
 		(`"\x0a;\x2014;\x2f9f4;"`,
 			[
@@ -81,13 +82,13 @@ type dummytoken = (ty, value);
 
 fn tokeq(have: token, want: dummytoken) bool =
 	have.0 == want.0 && match (have.1) {
-	case void =>
-		yield true;
-	case let s: str =>
-		yield want.1 is str && (want.1 as str) == s;
-	case let r: rune =>
-		yield want.1 is rune && (want.1 as rune) == r;
-	case let b: bool =>
-		yield want.1 is bool && (want.1 as bool) == b;
-	};
+		case void =>
+			yield true;
+		case let s: str =>
+			yield want.1 is str && (want.1 as str) == s;
+		case let r: rune =>
+			yield want.1 is rune && (want.1 as rune) == r;
+		case let b: bool =>
+			yield want.1 is bool && (want.1 as bool) == b;
+		};
 

kojote/lex/token.ha

@@ -27,8 +27,7 @@ export fn tokstr(tok: token) str = {
 	case ty::KEYWORD =>
 		return fmt::bsprintf(buf, ":{}", tok.1 as str);
 	case ty::STRING =>
-		// TODO: escape string before printing
-		return fmt::bsprintf(buf, "\"{}\"", tok.1 as str);
+		return fmt::bsprintf(buf, "\"{}\"", escape(tok.1 as str));
 	case ty::CHAR =>
 		let rn = tok.1 as rune;
 		for (let i = 0z; i < len(longcharnames); i += 1) {
@@ -37,10 +36,10 @@ export fn tokstr(tok: token) str = {
 					longcharnames[i].0);
 			};
 		};
-		if (ascii::isgraph(rn)) {
+		if (isgraph(rn)) {
 			return fmt::bsprintf(buf, "#\\{}", rn);
 		} else {
-			return fmt::bsprintf(buf, "#\\x{x};", rn: u32);
+			return fmt::bsprintf(buf, "#\\x{:x};", rn: u32);
 		};
 	case ty::NUMBER =>
 		return tok.1 as str;

kojote/lex/util.ha

@@ -0,0 +1,69 @@
+use ascii;
+use fmt;
+use memio;
+use strings;
+use io;
+use sort;
+
+use unicode;
+
+def graphtable: [unicode::gc::Zs]bool = [
+	false, false, false, false, false,   // C
+	true, true, true, true, true,        // L
+	true, true, true,                    // M
+	true, true, true,                    // N
+	true, true, true, true, true, true,  // P
+	true, true, true, true,              // S
+	false, false, false,                 // Z
+];
+
+// Sorted to use with [[sort::search]].
+def escapetable: [_](rune, rune) = [
+	('\0',   '0'),
+	('\a',   'a'),
+	('\b',   'b'),
+	('\t',   't'),
+	('\n',   'n'),
+	('\v',   'v'),
+	('\f',   'f'),
+	('\r',   'r'),
+	('\x1b', 'e'),
+	('"',    '"'),
+	('\\',   '\\'),
+];
+
+fn escapetable_cmpfunc(a: const *opaque, b: const *opaque) int =
+	(a: *(rune, rune)).0: int - (b: *(rune, rune)).0: int;
+
+// Returns whether a rune is a graphical character.
+fn isgraph(r: rune) bool =
+	if (r == ' ') true else graphtable[unicode::rune_gc(r)];
+
+// Escapes a string.
+fn escape(s: str) str = {
+	static let buf: [2048]u8 = [0...];
+	let buf = memio::fixed(buf);
+	let iter = strings::iter(s);
+
+	for (let ch => strings::next(&iter)) {
+		if (isgraph(ch)) {
+			memio::appendrune(&buf, ch)!;
+		} else {
+			match (sort::search(
+					escapetable: []opaque,
+					size((rune, rune)),
+					&ch: const *opaque,
+					&escapetable_cmpfunc)) {
+			case let sz: size =>
+				memio::appendrune(&buf, '\\')!;
+				memio::appendrune(&buf, escapetable[sz].1)!;
+			case void =>
+				static let hexbuf: [8]u8 = [0...];
+				memio::concat(&buf, fmt::bsprintf(
+					hexbuf, `\x{:x};`, ch: u32))!;
+			};
+		};
+	};
+
+	return memio::string(&buf)!;
+};