322 322 el = E(0); 323 323 } 324 324 return new App(pos, new Var(pos,"if"), cond, new Fun(thenPos,[],th), new Fun(elsePos,[],el)); 325 325 } 326 326 327 327 AST parsePatternMatch(LexPosition pos) 328 328 { 329 - // case "(" pmExpr ")" CASES 329 + // case pmExpr CASES 330 330 //==> 331 331 // let pmVar = pmExpr in (... let pmTryFirst = ... in pmTryFirst()) 332 - eat("(", "after case"); 333 332 AST pmExpr = E(0); 334 - eat(")", "after case"); 335 333 string pmVar = freshVarName(); 336 334 string pmTryFirst = freshVarName(); 337 335 AST pmBody = parsePatternMatchCases(pmVar, pmTryFirst, 338 336 new App(pos, new Var(pos, pmTryFirst))); 339 337 return new Let(pos, pmVar, [], pmExpr, pmBody); 340 338 } 341 339 342 340 AST parsePatternMatchCases(string pmVar, string tryThisBranchVar, AST thenDoThis) 343 341 { 344 - // when( pat ) { cBody } 342 + // when pat: cBody 345 343 //==> 346 344 // ... let failBranchVar = ... in 347 345 // let tryThisBranchVar = fun(){ if(test){cBody}else{failBranchVar()} } in thenDoThis 348 346 if( tryEat("when") ) 349 347 { 350 348 auto pos = currentPosition(); 351 349 string failBranchVar = freshVarName(); 352 350 353 - eat("(", "after when"); 354 351 auto pr = parsePattern(); 355 - eat(")", "after when"); 356 - eat("{", "after pattern"); 357 - AST cBody = Body(); 352 + eat(":", "after when pattern"); 353 + AST cBody = E(0); 358 354 AST judgement = new App(pos, new Var(pos, "if"), 359 355 ppTest(pmVar, pr), new Fun(pos,[],ppBind(pmVar, pr, cBody)), 360 356 new Var(pos, failBranchVar)); 361 - eat("}", "after pattern clause"); 362 357 return parsePatternMatchCases(pmVar, failBranchVar, 363 358 new Let(pos, tryThisBranchVar, [], 364 359 new Fun(pos,[],judgement), thenDoThis) 365 360 ); 366 361 } 367 362 else 368 363 { ................................................................................ 659 654 assert_eq(parseString(`x{y:1}`), call(var(".="),var("x"),strl("y"),intl(1))); 660 655 } 661 656 662 657 unittest 663 658 { 664 659 assert_nothrow(parseString(` 665 660 case( 1 ) 666 - when(x){1} 661 + when(x): 1 667 662 `)); 668 663 assert_nothrow(parseString(` 669 - case( 1 ) 670 - when({aaaa:_}){1} 664 + case 1 665 + when {aaaa:_}: 1 671 666 `)); 672 667 assert_nothrow(parseString(` 673 - case( 1 ) 674 - when({aaaa:@value(x)}){1} 675 - when({aaaa:{bbb:_}, ccc:123}){1} 668 + case 1 669 + when {aaaa:@value(x)}: 1 670 + when {aaaa:{bbb:_}, ccc:123}: 1 676 671 `)); 677 672 } 678 673 679 674 unittest 680 675 { 681 676 // test for omitting { .. } 682 677 assert_nothrow(parseString(` 683 678 if(1) 2 else 3 684 679 `)); 685 680 assert_nothrow(parseString(` 686 681 if(1) x{y:z} else 3 687 682 `)); 688 683 }