Curry + seq

src/test.nim

@@ -67,30 +67,46 @@ proc initParser(str: string): ParserResult =
     tokens: newSeq[Token](),
   ).ok()
 
-proc ch(parser: Parser, c: char): ParserResult =
-  let state = parser.state
+func ch(c1: char): (Parser -> ParserResult) {.inline.} =
+  return func(parser: Parser): ParserResult =
+    let state = parser.state
+    let c2 = state.stream[state.position]
 
-  if state.stream[0] == c:
-    Parser(
-      state: ParserState(
-        stream: state.stream[1 .. ^1],
-        position: parser.state.position + 1,
-        lastPosition: parser.state.position,
-      ),
-      tokens: parser.tokens & Token(value: c)
-    ).ok()
-  else:
-    err((parser, &"Expected {c}"))
+    if c1 == c2:
+      return Parser(
+        state: ParserState(
+          stream: state.stream,
+          position: state.lastPosition + 1,
+          lastPosition: parser.state.position,
+        ),
+        tokens: parser.tokens & Token(value: c2)
+      ).ok()
+    else:
+      return err((parser, &"Expected {c2} at {state.lastPosition}, got {c1}"))
+
+
+proc parseSeq(parser: ParserResult, xs: seq[Parser -> ParserResult]): ParserResult =
+  xs.foldl(a.flatMap(b), parser)
 
 # type R = Result[int, string]
 
 # echo R.ok 4
 
+let fooParser = initParser("FOO").parseSeq(@[
+  ch('F'),
+  ch('O'),
+  ch('O'),
+])
 
-echo initParser("Foo")
-  .flatMap((x: Parser) => ch(x, c = 'F'))
-  .flatMap((x: Parser) => ch(x, c = 'o'))
-  .flatMap((x: Parser) => ch(x, c = 'o'))
+echo fooParser
+
+
+# echo initParser("FUo")
+#   .flatMap(ch('F'))
+#   .flatMap(ch('o'))
+#   .flatMap(ch('o'))
+  # .flatMap((x: Parser) => ch(x, c = 'o'))
+  # .flatMap((x: Parser) => ch(x, c = 'o'))
 
 # proc parseStars