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