Fix "not match" and "not if" causing a syntax error (#3449)

* Updating 4th example of the STYLE_GUIDE's multi-function-call section * Add cond and whileloop to atom in ast/parser.c This fixes issue #2988, by allowing `if` and `while` to be used as expressions following the `not` operator (bzw. any other unary operator). * Also include forloop in atom in ast/parser.c `not for` had not been mentionned in #2988. Also updates the comment preceding `DEF(atom)`. * Add tests around #2988 * Untangle patch-issue-3441 This reverts commit 8121944. * Fix match guard being parsed as regular condition * Update grammar file
ponylang · Jan 28, 2020 · 4081905 · 4081905
1 parent d8b5665
commit 4081905
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Showing 3 changed files with 131 additions and 11 deletions.
diff --git a/pony.g b/pony.g
@@ -128,7 +128,7 @@ withelem
   ;
 
 caseexpr
-  : '|' ('\\' ID (',' ID)* '\\')? pattern? ('if' rawseq)? ('=>' rawseq)?
+  : '|' ('\\' ID (',' ID)* '\\')? casepattern? ('if' rawseq)? ('=>' rawseq)?
   ;
 
 elseiftype
@@ -162,6 +162,11 @@ nextpattern
   | nextparampattern
   ;
 
+casepattern
+  : ('var' | 'let' | 'embed') ID (':' type)?
+  | caseparampattern
+  ;
+
 pattern
   : ('var' | 'let' | 'embed') ID (':' type)?
   | parampattern
@@ -172,6 +177,11 @@ nextparampattern
   | nextpostfix
   ;
 
+caseparampattern
+  : ('not' | 'addressof' | '-' | '-~' | MINUS_NEW | MINUS_TILDE_NEW | 'digestof') caseparampattern
+  | casepostfix
+  ;
+
 parampattern
   : ('not' | 'addressof' | '-' | '-~' | MINUS_NEW | MINUS_TILDE_NEW | 'digestof') parampattern
   | postfix
@@ -181,8 +191,12 @@ nextpostfix
   : nextatom antlr_2*
   ;
 
+casepostfix
+  : caseatom antlr_3*
+  ;
+
 postfix
-  : atom antlr_3*
+  : atom antlr_4*
   ;
 
 call
@@ -212,6 +226,24 @@ nextatom
   | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
   | '@' (ID | STRING) typeargs? ('(' | LPAREN_NEW) positional? named? ')' '?'?
   | '__loc'
+  | 'if' ('\\' ID (',' ID)* '\\')? rawseq 'then' rawseq (elseif | ('else' annotatedrawseq))? 'end'
+  | 'while' ('\\' ID (',' ID)* '\\')? rawseq 'do' rawseq ('else' annotatedrawseq)? 'end'
+  | 'for' ('\\' ID (',' ID)* '\\')? idseq 'in' rawseq 'do' rawseq ('else' annotatedrawseq)? 'end'
+  ;
+
+caseatom
+  : ID
+  | 'this'
+  | literal
+  | ('(' | LPAREN_NEW) rawseq tuple? ')'
+  | ('[' | LSQUARE_NEW) ('as' type ':')? rawseq? ']'
+  | 'object' ('\\' ID (',' ID)* '\\')? cap? ('is' type)? members 'end'
+  | '{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
+  | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
+  | '@' (ID | STRING) typeargs? ('(' | LPAREN_NEW) positional? named? ')' '?'?
+  | '__loc'
+  | 'while' ('\\' ID (',' ID)* '\\')? rawseq 'do' rawseq ('else' annotatedrawseq)? 'end'
+  | 'for' ('\\' ID (',' ID)* '\\')? idseq 'in' rawseq 'do' rawseq ('else' annotatedrawseq)? 'end'
   ;
 
 atom
@@ -225,6 +257,9 @@ atom
   | '@{' ('\\' ID (',' ID)* '\\')? cap? ID? typeparams? ('(' | LPAREN_NEW) lambdaparams? ')' lambdacaptures? (':' type)? '?'? '=>' rawseq '}' cap?
   | '@' (ID | STRING) typeargs? ('(' | LPAREN_NEW) positional? named? ')' '?'?
   | '__loc'
+  | 'if' ('\\' ID (',' ID)* '\\')? rawseq 'then' rawseq (elseif | ('else' annotatedrawseq))? 'end'
+  | 'while' ('\\' ID (',' ID)* '\\')? rawseq 'do' rawseq ('else' annotatedrawseq)? 'end'
+  | 'for' ('\\' ID (',' ID)* '\\')? idseq 'in' rawseq 'do' rawseq ('else' annotatedrawseq)? 'end'
   ;
 
 tuple
@@ -285,7 +320,7 @@ tupletype
   ;
 
 infixtype
-  : type antlr_4*
+  : type antlr_5*
   ;
 
 isecttype
@@ -380,6 +415,14 @@ antlr_3
   ;
 
 antlr_4
+  : dot
+  | tilde
+  | chain
+  | typeargs
+  | call
+  ;
+
+antlr_5
   : uniontype
   | isecttype
   ;

diff --git a/src/libponyc/ast/parser.c b/src/libponyc/ast/parser.c
@@ -30,7 +30,11 @@ DECL(pattern);
 DECL(idseq_in_seq);
 DECL(members);
 DECL(thisliteral);
-
+DECL(cond);
+DECL(whileloop);
+DECL(forloop);
+DECL(caseatom);
+DECL(caseparampattern);
 
 /* Precedence
  *
@@ -519,18 +523,27 @@ DEF(ffi);
   OPT TOKEN(NULL, TK_QUESTION);
   DONE();
 
-// ref | this | literal | tuple | array | object | lambda | barelambda | ffi |
+// atom
+// ref | this | literal | tuple | array | object | lambda | barelambda | ffi | cond | whileloop | forloop
 // location
 DEF(atom);
   RULE("value", ref, thisliteral, literal, groupedexpr, array, object, lambda,
-    barelambda, ffi, location);
+    barelambda, ffi, location, cond, whileloop, forloop);
+  DONE();
+
+// caseatom:
+// ref | this | literal | tuple | array | object | lambda | barelambda | ffi | whileloop | forloop
+// location
+DEF(caseatom);
+  RULE("value", ref, thisliteral, literal, groupedexpr, array, object, lambda,
+    barelambda, ffi, location, whileloop, forloop);
   DONE();
 
-// ref | this | literal | tuple | array | object | lambda | barelambda| ffi |
+// ref | this | literal | tuple | array | object | lambda | barelambda| ffi | cond | whileloop | forloop
 // location
 DEF(nextatom);
   RULE("value", ref, thisliteral, literal, nextgroupedexpr, nextarray, object,
-    lambda, barelambda, ffi, location);
+    lambda, barelambda, ffi, location, cond, whileloop, forloop);
   DONE();
 
 // DOT ID
@@ -578,6 +591,12 @@ DEF(postfix);
   SEQ("postfix expression", dot, tilde, chain, qualify, call);
   DONE();
 
+// atom {dot | tilde | chain | qualify | call}
+DEF(casepostfix);
+  RULE("value", caseatom);
+  SEQ("postfix expression", dot, tilde, chain, qualify, call);
+  DONE();
+
 // atom {dot | tilde | chain | qualify | call}
 DEF(nextpostfix);
   RULE("value", nextatom);
@@ -605,6 +624,19 @@ DEF(prefix);
   RULE("expression", parampattern);
   DONE();
 
+// (NOT | AMP | MINUS | MINUS_TILDE | MINUS_NEW | MINUS_TILDE_NEW | DIGESTOF)
+// casepattern
+DEF(caseprefix);
+  PRINT_INLINE();
+  TOKEN("prefix", TK_NOT, TK_ADDRESS, TK_MINUS, TK_MINUS_TILDE, TK_MINUS_NEW,
+    TK_MINUS_TILDE_NEW, TK_DIGESTOF);
+  MAP_ID(TK_MINUS, TK_UNARY_MINUS);
+  MAP_ID(TK_MINUS_TILDE, TK_UNARY_MINUS_TILDE);
+  MAP_ID(TK_MINUS_NEW, TK_UNARY_MINUS);
+  MAP_ID(TK_MINUS_TILDE_NEW, TK_UNARY_MINUS_TILDE);
+  RULE("expression", caseparampattern);
+  DONE();
+
 // (NOT | AMP | MINUS_NEW | MINUS_TILDE_NEW | DIGESTOF) pattern
 DEF(nextprefix);
   PRINT_INLINE();
@@ -620,14 +652,24 @@ DEF(parampattern);
   RULE("pattern", prefix, postfix);
   DONE();
 
+// (caseprefix | casepostfix)
+DEF(caseparampattern);
+  RULE("pattern", caseprefix, casepostfix);
+  DONE();
+
 // (prefix | postfix)
 DEF(nextparampattern);
   RULE("pattern", nextprefix, nextpostfix);
   DONE();
 
 // (local | prefix | postfix)
 DEF(pattern);
-RULE("pattern", local, parampattern);
+  RULE("pattern", local, parampattern);
+  DONE();
+
+// (local | prefix | postfix)
+DEF(casepattern);
+  RULE("pattern", local, caseparampattern);
   DONE();
 
 // (local | prefix | postfix)
@@ -763,13 +805,13 @@ DEF(iftypeset);
   TERMINATE("iftype expression", TK_END);
   DONE();
 
-// PIPE [annotations] [infix] [WHERE rawseq] [ARROW rawseq]
+// PIPE [annotations] [infix] [IF rawseq] [ARROW rawseq]
 DEF(caseexpr);
   AST_NODE(TK_CASE);
   SCOPE();
   SKIP(NULL, TK_PIPE);
   ANNOTATE(annotations);
-  OPT RULE("case pattern", pattern);
+  OPT RULE("case pattern", casepattern);
   IF(TK_IF, RULE("guard expression", rawseq));
   IF(TK_DBLARROW, RULE("case body", rawseq));
   DONE();

diff --git a/test/libponyc/sugar.cc b/test/libponyc/sugar.cc
@@ -644,6 +644,18 @@ TEST_F(SugarTest, IfWithElse)
 }
 
 
+TEST_F(SugarTest, NotIf)
+{
+  const char* short_form =
+    "class Foo\n"
+    "  fun f() =>\n"
+    "    let a = true\n"
+    "    if not if a then not a else a end then a end";
+
+  TEST_COMPILE(short_form);
+}
+
+
 TEST_F(SugarTest, WhileWithoutElse)
 {
   const char* short_form =
@@ -675,6 +687,18 @@ TEST_F(SugarTest, WhileWithElse)
 }
 
 
+TEST_F(SugarTest, NotWhileWithElse)
+{
+  const char* short_form =
+    "class Foo\n"
+    "  fun f(): U32 val =>\n"
+    "    let a = true\n"
+    "    not while a do true else false end";
+
+  TEST_COMPILE(short_form);
+}
+
+
 TEST_F(SugarTest, TryWithElseAndThen)
 {
   const char* short_form =
@@ -806,6 +830,17 @@ TEST_F(SugarTest, ForWithElse)
 }
 
 
+TEST_F(SugarTest, NotForWithElse)
+{
+  const char* short_form =
+    "class Foo\n"
+    "  fun f()=>\n"
+    "    not for i in 1 do true else false end";
+
+  TEST_COMPILE(short_form);
+}
+
+
 TEST_F(SugarTest, MultiIteratorFor)
 {
   const char* short_form =