Remove match placeholders

Author: rattrayalex

src/parser/expression.js

@@ -291,13 +291,7 @@ pp.parseExprOp = function(left, leftStartPos, leftStartLoc, minPrec, noIn) {
 // Parse unary operators, both prefix and postfix.
 
 pp.parseMaybeUnary = function (refShorthandDefaultPos) {
-  const matchCaseBinaryPlusMin = this.hasPlugin("lightscript") &&
-    this.state.inMatchCaseTest &&
-    this.match(tt.plusMin) &&
-    this.state.tokens[this.state.tokens.length - 1].value !== "!" &&
-    this.isNextCharWhitespace();
-
-  if (this.state.type.prefix && !matchCaseBinaryPlusMin) {
+  if (this.state.type.prefix) {
     if (this.hasPlugin("lightscript") && this.match(tt.plusMin)) {
       if (this.isNextCharWhitespace()) this.unexpected(null, "Unary +/- cannot be followed by a space in lightscript.");
     }
@@ -313,19 +307,7 @@ pp.parseMaybeUnary = function (refShorthandDefaultPos) {
     this.next();
 
     const argType = this.state.type;
-
-    // change precedence / allow autofill of `not` within `match` test
-    if (this.hasPlugin("lightscript") && node.operator === "!" && this.state.inMatchCaseTest && !argType.startsExpr) {
-      if (this.match(tt.colon) || this.match(tt.logicalOR) || this.match(tt.logicalAND)) {
-        // allow `| not:`, `| !!:`, `| not or x:`
-        node.argument = this.parseMatchCasePlaceholder();
-      } else {
-        // change precedence of `| not < 3:` to `!(x < 3)` from `(!x) < 3`
-        node.argument = this.parseExprOps();
-      }
-    } else {
-      node.argument = this.parseMaybeUnary();
-    }
+    node.argument = this.parseMaybeUnary();
 
     this.addExtra(node, "parenthesizedArgument", argType === tt.parenL && (!node.argument.extra || !node.argument.extra.parenthesized));
 
@@ -763,14 +745,11 @@ pp.parseExprAtom = function (refShorthandDefaultPos) {
       }
 
     case tt.dot:
-      if (this.hasPlugin("lightscript") && this.lookahead().type === tt.num && !this.allowMatchCasePlaceholder()) {
+      if (this.hasPlugin("lightscript") && this.lookahead().type === tt.num) {
         this.unexpected(null, "Decimal numbers must be prefixed with a `0` in LightScript (eg; `0.1`).");
       }
 
     default:
-      if (this.hasPlugin("lightscript") && this.allowMatchCasePlaceholder()) {
-        return this.parseMatchCasePlaceholder();
-      }
       this.unexpected();
   }
 };

src/plugins/lightscript.js

@@ -655,66 +655,6 @@ pp.parseMatchCaseTest = function (node) {
   this.state.inMatchCaseTest = false;
 };
 
-pp.isBinaryTokenForMatchCase = function (tokenType) {
-  return (
-    tokenType.binop != null &&
-    tokenType !== tt.logicalOR &&
-    tokenType !== tt.logicalAND &&
-    tokenType !== tt.bitwiseOR
-  );
-};
-
-pp.isSubscriptTokenForMatchCase = function (tokenType) {
-  return (
-    tokenType === tt.dot ||
-    tokenType === tt.elvis ||
-    tokenType === tt.tilde
-  );
-};
-
-pp.allowMatchCasePlaceholder = function () {
-  if (!this.state.inMatchCaseTest) {
-    return false;
-  }
-  const cur = this.state.type;
-  const prev = this.state.tokens[this.state.tokens.length - 1].type;
-
-  // don't allow two binary tokens in a row to use placeholders, eg; `+ *`
-  if (this.isBinaryTokenForMatchCase(cur)) {
-    return !this.isBinaryTokenForMatchCase(prev);
-  }
-  // don't allow two subscripts in a row to use placeholders, eg; `..`
-  if (this.isSubscriptTokenForMatchCase(cur)) {
-    return !this.isSubscriptTokenForMatchCase(prev);
-  }
-  return false;
-};
-
-pp.parseMatchCaseTestPattern = function () {
-  if (!this.state.allowMatchCaseTestPattern) {
-    this.unexpected(null, "Only one pattern allowed per match case test.");
-  }
-
-  const oldInMatchCaseTestPattern = this.state.inMatchCaseTestPattern;
-  this.state.inMatchCaseTestPattern = true;
-
-  const node = this.parseBindingAtom();
-
-  // once we have finished recursing through a pattern, disallow future patterns
-  this.state.inMatchCaseTestPattern = oldInMatchCaseTestPattern;
-  if (this.state.inMatchCaseTestPattern === false) {
-    this.state.allowMatchCaseTestPattern = false;
-  }
-
-  return node;
-};
-
-pp.parseMatchCasePlaceholder = function () {
-  // use the blank space as an empty value (perhaps 0-length would be better)
-  const node = this.startNodeAt(this.state.lastTokEnd, this.state.lastTokEndLoc);
-  return this.finishNodeAt(node, "PlaceholderExpression", this.state.start, this.state.startLoc);
-};
-
 
 export default function (instance) {
 

src/tokenizer/state.js

@@ -41,8 +41,6 @@ export default class State {
     // for lightscript
     this.indentLevel = 0;
     this.inMatchCaseTest = false;
-    this.inMatchCaseTestPattern = false;
-    this.allowMatchCaseTestPattern = false;
 
     this.type = tt.eof;
     this.value = null;