From e28babec3153cf27aa55f611eea9cbe7cdea1e2d Mon Sep 17 00:00:00 2001
From: Drew Youngwerth <drew@youngwerth.com>
Date: Wed, 28 Aug 2024 19:04:03 -0700
Subject: [PATCH] [Voi-88] Generic parameter parsing (#26)

* Standardized reader macro match function

* Semi working prototype

* Add tests
---
 src/parser.mts                                | 45 ++++++++++++-----
 src/reader-macros/array-literal.mts           |  2 +-
 src/reader-macros/boolean.mts                 |  2 +-
 src/reader-macros/comment.mts                 |  2 +-
 src/reader-macros/dictionary-literal.mts      |  2 +-
 src/reader-macros/float.mts                   |  2 +-
 src/reader-macros/generics.mts                | 11 +++++
 src/reader-macros/index.mts                   | 30 +++---------
 src/reader-macros/int.mts                     |  2 +-
 src/reader-macros/object-literal.mts          |  2 +-
 src/reader-macros/scientific-e-notation.mts   |  2 +-
 src/reader-macros/string.mts                  |  2 +-
 src/reader-macros/types.mts                   |  2 +-
 .../__tests__/fixtures/desugarred-ast.mts     |  3 ++
 .../__tests__/fixtures/void-file.mts          |  8 ++++
 .../surface-language/functional-notation.mts  | 48 ++++++++++++++++---
 .../surface-language/interpret-whitespace.mts |  6 +--
 17 files changed, 115 insertions(+), 56 deletions(-)
 create mode 100644 src/reader-macros/generics.mts

diff --git a/src/parser.mts b/src/parser.mts
index 60aa3643..16ba61d9 100644
--- a/src/parser.mts
+++ b/src/parser.mts
@@ -23,22 +23,14 @@ export function parse(file: File, opts: ParseOpts = {}): List {
     value: !opts.nested ? ["ast", ","] : [],
   });
 
+  let prev: Token | undefined = undefined;
+  let cur: Token | undefined = undefined;
   while (file.hasCharacters) {
     const token = lexer(file);
+    prev = cur;
+    cur = token;
 
-    const readerMacro = getReaderMacroForToken(token);
-
-    if (readerMacro) {
-      const result = readerMacro(file, {
-        token,
-        reader: (file, terminator, parent) =>
-          parse(file, {
-            nested: true,
-            terminator,
-            parent: parent ?? opts.parent,
-          }),
-      });
-      if (typeof result !== "undefined") list.push(result);
+    if (processWithReaderMacro(token, prev, file, opts, list)) {
       continue;
     }
 
@@ -154,3 +146,30 @@ const consumeSpaces = (file: File, token: Token) => {
     token.addChar(file.consumeChar());
   }
 };
+
+/** Returns true if token was matched with and processed by a macro  */
+const processWithReaderMacro = (
+  token: Token,
+  prev: Token | undefined,
+  file: File,
+  opts: ParseOpts,
+  list: List
+) => {
+  const readerMacro = getReaderMacroForToken(token, prev);
+  if (!readerMacro) return undefined;
+
+  const result = readerMacro(file, {
+    token,
+    reader: (file, terminator, parent) =>
+      parse(file, {
+        nested: true,
+        terminator,
+        parent: parent ?? opts.parent,
+      }),
+  });
+
+  if (!result) return undefined;
+
+  list.push(result);
+  return true;
+};
diff --git a/src/reader-macros/array-literal.mts b/src/reader-macros/array-literal.mts
index 0263bdf8..8fa1a9fd 100644
--- a/src/reader-macros/array-literal.mts
+++ b/src/reader-macros/array-literal.mts
@@ -1,7 +1,7 @@
 import { ReaderMacro } from "./types.mjs";
 
 export const arrayLiteralMacro: ReaderMacro = {
-  tag: "[",
+  match: (t) => t.value === "[",
   macro: (file, { reader }) => {
     const items = reader(file, "]");
     return items.insert("array").insert(",", 1);
diff --git a/src/reader-macros/boolean.mts b/src/reader-macros/boolean.mts
index 9a56b3b2..1f3d3f8c 100644
--- a/src/reader-macros/boolean.mts
+++ b/src/reader-macros/boolean.mts
@@ -2,7 +2,7 @@ import { Bool } from "../syntax-objects/index.mjs";
 import { ReaderMacro } from "./types.mjs";
 
 export const booleanMacro: ReaderMacro = {
-  tag: /^true|false$/,
+  match: (t) => /^true|false$/.test(t.value),
   macro: (_, { token }) =>
     new Bool({
       value: token.is("true"),
diff --git a/src/reader-macros/comment.mts b/src/reader-macros/comment.mts
index 78e61945..d159b6b2 100644
--- a/src/reader-macros/comment.mts
+++ b/src/reader-macros/comment.mts
@@ -2,7 +2,7 @@ import { noop } from "../syntax-objects/index.mjs";
 import { ReaderMacro } from "./types.mjs";
 
 export const comment: ReaderMacro = {
-  tag: /^\/\/[^\s]*$/,
+  match: (t) => /^\/\/[^\s]*$/.test(t.value),
   macro: (file) => {
     while (file.hasCharacters) {
       if (file.next === "\n") break;
diff --git a/src/reader-macros/dictionary-literal.mts b/src/reader-macros/dictionary-literal.mts
index 764d0212..972a752a 100644
--- a/src/reader-macros/dictionary-literal.mts
+++ b/src/reader-macros/dictionary-literal.mts
@@ -2,7 +2,7 @@ import { Identifier, List } from "../syntax-objects/index.mjs";
 import { ReaderMacro } from "./types.mjs";
 
 export const dictionaryLiteralMacro: ReaderMacro = {
-  tag: "#{",
+  match: (t) => t.value === "#{",
   macro: (file, { reader }) => {
     const dict = new Identifier({ value: "dict" });
     const items = reader(file, "}");
diff --git a/src/reader-macros/float.mts b/src/reader-macros/float.mts
index b1e729af..b9de0c89 100644
--- a/src/reader-macros/float.mts
+++ b/src/reader-macros/float.mts
@@ -2,7 +2,7 @@ import { Float } from "../syntax-objects/index.mjs";
 import { ReaderMacro } from "./types.mjs";
 
 export const floatMacro: ReaderMacro = {
-  tag: /^[+-]?\d+\.\d+$/,
+  match: (t) => /^[+-]?\d+\.\d+$/.test(t.value),
   macro: (_, { token }) =>
     new Float({
       value: Number(token.value),
diff --git a/src/reader-macros/generics.mts b/src/reader-macros/generics.mts
new file mode 100644
index 00000000..514ee76e
--- /dev/null
+++ b/src/reader-macros/generics.mts
@@ -0,0 +1,11 @@
+import { ReaderMacro } from "./types.mjs";
+
+export const genericsMacro: ReaderMacro = {
+  match: (t, prev) => {
+    return t.value === "<" && !!prev && /\w+/.test(prev.value);
+  },
+  macro: (file, { reader }) => {
+    const items = reader(file, ">");
+    return items.insert("generics").insert(",", 1);
+  },
+};
diff --git a/src/reader-macros/index.mts b/src/reader-macros/index.mts
index 56c21246..95ec77dc 100644
--- a/src/reader-macros/index.mts
+++ b/src/reader-macros/index.mts
@@ -9,6 +9,7 @@ import { scientificENotationMacro } from "./scientific-e-notation.mjs";
 import { stringMacro } from "./string.mjs";
 import { objectLiteralMacro } from "./object-literal.mjs";
 import { ReaderMacro } from "./types.mjs";
+import { genericsMacro } from "./generics.mjs";
 
 const macros = [
   objectLiteralMacro,
@@ -20,30 +21,11 @@ const macros = [
   stringMacro,
   comment,
   booleanMacro,
+  genericsMacro,
 ];
 
-const readerMacros = macros.reduce(
-  ({ map, patterns }, reader) => {
-    if (typeof reader.tag === "string") {
-      map.set(reader.tag, reader.macro);
-      return { map, patterns };
-    }
-
-    patterns.push({ pattern: reader.tag, macro: reader.macro });
-    return { map, patterns };
-  },
-  {
-    map: new Map<string, ReaderMacro["macro"]>(),
-    patterns: [] as { pattern: RegExp; macro: ReaderMacro["macro"] }[],
-  }
-);
-
 export const getReaderMacroForToken = (
-  token: Token
-): ReaderMacro["macro"] | undefined => {
-  return (
-    readerMacros.map.get(token.value) ??
-    readerMacros.patterns.find(({ pattern }) => pattern.test(token.value))
-      ?.macro
-  );
-};
+  token: Token,
+  prev?: Token
+): ReaderMacro["macro"] | undefined =>
+  macros.find((m) => m.match(token, prev))?.macro;
diff --git a/src/reader-macros/int.mts b/src/reader-macros/int.mts
index 6d021b09..602c09cc 100644
--- a/src/reader-macros/int.mts
+++ b/src/reader-macros/int.mts
@@ -2,7 +2,7 @@ import { Int } from "../syntax-objects/index.mjs";
 import { ReaderMacro } from "./types.mjs";
 
 export const intMacro: ReaderMacro = {
-  tag: /^[+-]?\d+$/,
+  match: (t) => /^[+-]?\d+$/.test(t.value),
   macro: (_, { token }) =>
     new Int({
       value: Number(token.value),
diff --git a/src/reader-macros/object-literal.mts b/src/reader-macros/object-literal.mts
index d148b0aa..a24613aa 100644
--- a/src/reader-macros/object-literal.mts
+++ b/src/reader-macros/object-literal.mts
@@ -1,7 +1,7 @@
 import { ReaderMacro } from "./types.mjs";
 
 export const objectLiteralMacro: ReaderMacro = {
-  tag: "{",
+  match: (t) => t.value === "{",
   macro: (dream, { reader }) => {
     const items = reader(dream, "}");
     return items.insert("object").insert(",", 1);
diff --git a/src/reader-macros/scientific-e-notation.mts b/src/reader-macros/scientific-e-notation.mts
index 6db321e5..1a5d633a 100644
--- a/src/reader-macros/scientific-e-notation.mts
+++ b/src/reader-macros/scientific-e-notation.mts
@@ -3,7 +3,7 @@ import { ReaderMacro } from "./types.mjs";
 
 export const scientificENotationMacro: ReaderMacro = {
   /** Regex from Michael Dumas https://regexlib.com/REDetails.aspx?regexp_id=2457 */
-  tag: /^[+-]?\d(\.\d+)?[Ee][+-]?\d+$/,
+  match: (t) => /^[+-]?\d(\.\d+)?[Ee][+-]?\d+$/.test(t.value),
   macro: (_, { token }) =>
     new List({ location: token.location })
       .push(new Identifier({ value: "scientific-e-notion" }))
diff --git a/src/reader-macros/string.mts b/src/reader-macros/string.mts
index 8eef285f..893447eb 100644
--- a/src/reader-macros/string.mts
+++ b/src/reader-macros/string.mts
@@ -2,7 +2,7 @@ import { Identifier, StringLiteral } from "../syntax-objects/index.mjs";
 import { ReaderMacro } from "./types.mjs";
 
 export const stringMacro: ReaderMacro = {
-  tag: /^[\"\']$/,
+  match: (t) => /^[\"\']$/.test(t.value),
   macro: (file, { token }) => {
     const startChar = token.value;
     token.value = "";
diff --git a/src/reader-macros/types.mts b/src/reader-macros/types.mts
index 1c110b55..2df5ee00 100644
--- a/src/reader-macros/types.mts
+++ b/src/reader-macros/types.mts
@@ -3,7 +3,7 @@ import { Expr, List } from "../syntax-objects/index.mjs";
 import { Token } from "../lib/token.mjs";
 
 export interface ReaderMacro {
-  tag: string | RegExp;
+  match: (token: Token, prev?: Token) => boolean;
   macro: (
     file: File,
     opts: {
diff --git a/src/syntax-macros/surface-language/__tests__/fixtures/desugarred-ast.mts b/src/syntax-macros/surface-language/__tests__/fixtures/desugarred-ast.mts
index bbe1a137..70d1f7e7 100644
--- a/src/syntax-macros/surface-language/__tests__/fixtures/desugarred-ast.mts
+++ b/src/syntax-macros/surface-language/__tests__/fixtures/desugarred-ast.mts
@@ -94,6 +94,9 @@ export const desugarredAst = [
     8,
   ],
   ["let", ["=", ["tuple", "x", "y"], ["tuple", 1, 2]]],
+  ["+", ["Array", ["generics", "Hey", "There"], 1, 2, 3], 3],
+  ["obj", ["Test", ["generics", "T"]], ["object", [":", "c", "i32"]]],
+  ["fn", ["test", ["generics", "T"], [":", "a", 1]], "->", "i32"],
   [
     "fn",
     ["main"],
diff --git a/src/syntax-macros/surface-language/__tests__/fixtures/void-file.mts b/src/syntax-macros/surface-language/__tests__/fixtures/void-file.mts
index 1e81c792..8a5c2c70 100644
--- a/src/syntax-macros/surface-language/__tests__/fixtures/void-file.mts
+++ b/src/syntax-macros/surface-language/__tests__/fixtures/void-file.mts
@@ -54,6 +54,14 @@ closure_param_test(1, () => a, 3, () =>
 
 let (x, y) = (1, 2)
 
+Array<Hey, There>(1, 2, 3) + 3
+
+obj Test<T> {
+  c: i32
+}
+
+fn test<T>(a: 1) -> i32
+
 fn main()
   let a = ...test.hey + &other.now
   let x = 10 +
diff --git a/src/syntax-macros/surface-language/functional-notation.mts b/src/syntax-macros/surface-language/functional-notation.mts
index 822835e6..96249eea 100644
--- a/src/syntax-macros/surface-language/functional-notation.mts
+++ b/src/syntax-macros/surface-language/functional-notation.mts
@@ -1,5 +1,5 @@
 import { isOp } from "../../lib/grammar.mjs";
-import { List } from "../../syntax-objects/index.mjs";
+import { Expr, List } from "../../syntax-objects/index.mjs";
 
 export const functionalNotation = (list: List): List => {
   let isTuple = false;
@@ -10,11 +10,7 @@ export const functionalNotation = (list: List): List => {
 
     const nextExpr = array[index + 1];
     if (nextExpr && nextExpr.isList() && !isOp(expr)) {
-      const list = array.splice(index + 1, 1)[0] as List;
-      list.insert(expr);
-      list.insert(",", 1);
-      list.mayBeTuple = false;
-      return functionalNotation(list);
+      return processFnCall(expr, nextExpr, array, index);
     }
 
     if (list.mayBeTuple && expr.isIdentifier() && expr.is(",")) {
@@ -26,7 +22,47 @@ export const functionalNotation = (list: List): List => {
 
   if (isTuple) {
     result.insert("tuple");
+    result.insert(",");
   }
 
   return result;
 };
+
+const processFnCall = (
+  expr: Expr,
+  nextExpr: List,
+  array: Expr[],
+  index: number
+): List => {
+  if (nextExpr.calls("generics")) {
+    return processGenerics(expr, array, index);
+  }
+
+  return processParamList(expr, array, index);
+};
+
+const processGenerics = (expr: Expr, array: Expr[], index: number): List => {
+  const generics = array.splice(index + 1, 1)[0] as List;
+  generics.mayBeTuple = false;
+
+  const list = array[index + 1]?.isList()
+    ? (array.splice(index + 1, 1)[0] as List)
+    : new List({});
+
+  list.insert(",");
+  list.insert(expr);
+  list.mayBeTuple = false;
+  const functional = functionalNotation(list);
+
+  functional.insert(functionalNotation(generics), 2);
+  functional.insert(",", 3);
+  return functional;
+};
+
+const processParamList = (expr: Expr, array: Expr[], index: number): List => {
+  const list = array.splice(index + 1, 1)[0] as List;
+  list.insert(expr);
+  list.insert(",", 1);
+  list.mayBeTuple = false;
+  return functionalNotation(list);
+};
diff --git a/src/syntax-macros/surface-language/interpret-whitespace.mts b/src/syntax-macros/surface-language/interpret-whitespace.mts
index 9270184c..bebd750b 100644
--- a/src/syntax-macros/surface-language/interpret-whitespace.mts
+++ b/src/syntax-macros/surface-language/interpret-whitespace.mts
@@ -17,10 +17,10 @@ export const interpretWhitespace = (list: List, indentLevel?: number): List => {
   return transformed;
 };
 
-const elideParens = (list: Expr, indentLevel?: number): Expr => {
+const elideParens = (list: Expr, startIndentLevel?: number): Expr => {
   if (!list.isList()) return list;
   const transformed = new List({});
-  indentLevel = indentLevel ?? nextExprIndentLevel(list);
+  const indentLevel = startIndentLevel ?? nextExprIndentLevel(list);
 
   const nextLineHasChildExpr = () => nextExprIndentLevel(list) > indentLevel;
 
@@ -197,7 +197,7 @@ const addSibling = (child: Expr, siblings: List) => {
     return;
   }
 
-  if (!olderSibling?.isList()) {
+  if (!olderSibling?.isList() || olderSibling.calls("generics")) {
     siblings.push(child);
     return;
   }