parse, lex works

1 files changed, 212 insertions, 0 deletions

diff --git a/src/lib/core/parser.ts b/src/lib/core/parser.ts
new file mode 100644
index 0000000..fbbbdc2
--- /dev/null
+++ b/src/lib/core/parser.ts
@@ -0,0 +1,212 @@
+import { ASTNode, NodeType, ParserCtx, Token, TokenType } from "./common";
+import { IsWhitespace, Lex } from "./lexer";
+
+/* 
+start
+if no 'lastName'
+then:
+    expect nextToken to be a name
+    lastName = nextToken
+    goto start
+    
+else:
+    if nextToken is name
+    then:
+        // we already have a lastName
+        mutate last element of stack to push lastName as child
+        lastName = nextToken
+        goto start
+
+    else:
+        //nextToken is openParen or close paren
+        if nextToken is closeParen
+        then:
+            set last element of stack as child of prev element on stack
+            pop stack
+            // [stack[last - 1].children.push(stack.pop)
+            goto start
+        else if nextToken is openParen:
+            push lastName onto stack
+            goto start
+
+
+finally:
+    // only one element remains on the stack
+    return stack[0]
+
+
+    CALL ( param, CALL2 ( param2 ) )
+
+    param2 ret call2 param ret call
+
+    | call
+    |-- param
+    |-- | call2
+        |-- param2
+
+ */
+
+export type Error<T extends string> = ASTNode<NodeType.PARSER_ERROR, T, []>;
+
+export type PushChild<Node extends ASTNode, Child extends ASTNode> = {
+  type: Node["type"];
+  name: Node["name"];
+  children: [...Node["children"], Child];
+};
+
+export type PushChildToLastElementOfStack<
+  Stack extends ParserCtx["stack"],
+  Child extends ASTNode
+> = Stack extends [...infer Head, infer Tail extends ASTNode]
+  ? [...Head, PushChild<Tail, Child>]
+  : Stack extends [infer Only extends ASTNode]
+  ? [PushChild<Only, Child>]
+  : never;
+
+export type PushChildToSecondLastElementOfStack<
+  Stack extends ParserCtx["stack"],
+  Child extends ASTNode
+> = Stack extends [
+  ...infer Head,
+  infer Tail extends ASTNode,
+  infer Final extends ASTNode
+]
+  ? [...Head, PushChild<Tail, Child>, Final]
+  : Stack extends [infer Only extends ASTNode, infer Final extends ASTNode]
+  ? [PushChild<Only, Child>, Final]
+  : never;
+
+export type GetLastOnStack<Stack extends ParserCtx["stack"]> = Stack extends [
+  ...infer Head,
+  infer Tail extends ASTNode
+]
+  ? Tail
+  : Stack extends [infer Only extends ASTNode]
+  ? Only
+  : never;
+
+export type StackWithoutLast<Stack extends ParserCtx["stack"]> = Stack extends [
+  ...infer Head extends ASTNode[],
+  infer Tail
+]
+  ? [...Head]
+  : Stack extends [infer Only extends ASTNode]
+  ? []
+  : never;
+
+export type _Parse<Ctx extends ParserCtx> = Ctx["remainingTokens"] extends [
+  infer Head extends Token,
+  ...infer Tail extends readonly Token[]
+]
+  ? Ctx["lastName"] extends string
+    ? Head["type"] extends TokenType.UNIQUE_SYMBOL
+      ? // we already have a lastName
+        // mutate last element of stack to push lastName as child
+        // lastName = nextToken
+        // goto start
+        _Parse<{
+          lastName: Head["name"];
+          remainingTokens: Tail;
+          stack: PushChildToLastElementOfStack<
+            Ctx["stack"],
+            ASTNode<NodeType.LITERAL, Ctx["lastName"], []>
+          >;
+        }>
+      : //nextToken is openParen or close paren
+      Head["type"] extends TokenType.CLOSE_PAREN
+      ? // handle lastName
+        // set last element of stack as child of prev element on stack
+        // pop stack
+        // [stack[last - 1].children.push(stack.pop)
+        // goto start
+        _Parse<{
+          lastName: null;
+          remainingTokens: Tail;
+          // first push the last name onto the children of the top
+          // then push the top onto the children of the next
+          // then remove the top
+          stack: StackWithoutLast<
+            PushChildToSecondLastElementOfStack<
+              Ctx["stack"],
+              PushChild<
+                GetLastOnStack<Ctx["stack"]>,
+                ASTNode<NodeType.LITERAL, Ctx["lastName"], []>
+              >
+            >
+          >;
+        }>
+      : Head["type"] extends TokenType.OPEN_PAREN
+      ? // push lastName onto stack
+        // goto start
+        _Parse<{
+          lastName: null;
+          remainingTokens: Tail;
+          stack: [...Ctx["stack"], ASTNode<NodeType.CALL, Ctx["lastName"], []>];
+        }>
+      : Ctx & Error<`Was not expecting ${Head["type"]}`>
+    : // expect nextToken to be a name or close paren
+    Head["type"] extends TokenType.UNIQUE_SYMBOL
+    ? // lastName = nextToken
+      // goto start
+      _Parse<{
+        lastName: Head["name"];
+        remainingTokens: Tail;
+        stack: Ctx["stack"];
+      }>
+    : Head["type"] extends TokenType.CLOSE_PAREN
+    ? _Parse<{
+        lastName: null;
+        remainingTokens: Tail;
+        // push the top onto the children of the next
+        // then remove the top
+        stack: StackWithoutLast<
+          PushChildToSecondLastElementOfStack<
+            Ctx["stack"],
+            GetLastOnStack<Ctx["stack"]>
+          >
+        >;
+      }>
+    : Ctx &
+        Error<`Expected nextToken to be a name or close paren at ${Head["type"]}`>
+  : Ctx["stack"];
+
+// v1
+//   ? Ctx["isCollecting"] extends true
+//     ? Head["type"] extends TokenType.CLOSE_PAREN
+//       ? "return"
+//       : Head["type"] extends TokenType.UNIQUE_SYMBOL
+//       ? _Parse<{
+//         remainingTokens: Tail;
+//         isCollecting: true;
+//         name: Ctx["name"];
+//         // fuck, how to do this without advancing seek pointer??
+//         ret: [...Ctx["ret"], ASTNode;
+//       }>
+//       : Error<"Expected another name, or `)`">
+//     : Head["type"] extends TokenType.OPEN_PAREN
+//     ? _Parse<{
+//         remainingTokens: Tail;
+//         isCollecting: true;
+//         name: Ctx["name"];
+//         ret: Ctx["ret"];
+//       }>
+//     : Error<"Expected open paren">
+//   : Ctx["ret"];
+
+//v2
+//   ? Ctx["previousName"] extends null
+//     ? Head["type"] extends TokenType.UNIQUE_SYMBOL
+//       ? _Parse<{ remainingTokens: Tail; previousName: Head; node: Ctx["node"] }>
+//       : ASTNode<NodeType.PARSER_ERROR, "Expected name", []>
+//     : IsWhitespace<`${Head["type"]}`> extends true
+//         ? ASTNode<NodeType.PARSER_ERROR, "1", []>
+//         : ASTNode<NodeType.PARSER_ERROR, "2", []>
+//   : Ctx["node"];
+
+export type Parse<Raw extends readonly Token[]> = _Parse<{
+  lastName: null;
+  remainingTokens: Raw;
+  stack: [ASTNode<NodeType.ROOT, "ROOT", []>];
+}>;
+
+const a = "a" as any as Parse<Lex<"test(a)">>;