fix parser combinator

src/main/kotlin/blitz/parse/comb2/Predef.kt

@@ -0,0 +1,67 @@
+package blitz.parse.comb2
+
+import blitz.str.charsToString
+import kotlin.math.absoluteValue
+import kotlin.math.sign
+
+fun whitespaces(): Parser<Char, String> =
+    oneOf("\n\t\r\b ".toList())
+        .repeated()
+        .mapValue { it.charsToString() }
+
+fun digit(): Parser<Char, Char> =
+    oneOf("0123456789".toList())
+
+fun uintLit(): Parser<Char, UInt> =
+    withSpan(digit().repeated())
+        .verifyValueWithSpan { if (it.isEmpty()) "need digits after sign in num lit" else null }
+        .mapValue { it.charsToString().toUInt() }
+
+fun intLit(): Parser<Char, Int> =
+    choose(just('+').mapValue { +1 },
+           just('-').mapValue { -1 },
+           value(+1))
+        .then(uintLit())
+        .mapValue { (sign, v) -> sign * v.toInt() }
+
+fun floatLit(): Parser<Char, Double> =
+    intLit()
+        .then(just('.')
+            .then(uintLit())
+            .mapValue { it.second }
+            .orElseVal(0u))
+        .mapValue { (pre, post) ->
+            var p = post.toDouble()
+            while (p.absoluteValue >= 1) {
+                p *= 0.1
+            }
+
+            (pre.toDouble().absoluteValue + p) * pre.toDouble().sign
+        }
+
+fun escapeChar(): Parser<Char, Char> =
+    just('\\').then(
+        choose(just('"'),
+               just('\''),
+               just('\\'),
+               just('n').mapValue { '\n' },
+               just('r').mapValue { '\r' },
+               just('b').mapValue { '\b' },
+               just('t').mapValue { '\t' })
+            .mapErrors { listOf(ParseError(it.first().loc, "invalid escape sequence")) }
+    ).mapValue { it.second }
+
+fun stringLit(): Parser<Char, String> =
+    just('"')
+        .then(choose(escapeChar(),
+                     filter("a") { it != '"' })
+            .repeated())
+        .thenIgnore(just('"'))
+        .mapValue { (_, str) -> str.charsToString() }
+
+fun <I, O, T> Parser<I, O>.delimitedBy(delim: Parser<I, T>): Parser<I, List<O>> =
+    thenIgnore(delim)
+        .repeated()
+        .then(this)
+        .mapValue { (a, b) -> a + b }
+        .orElse(value(listOf()))