Update the CEL Grammar to support the lexis for Google SQL strings (#46)

Closes #45: Ensure CEL Grammar is Google SQL compatible.
google · Jun 7, 2018 · 2226ee7 · 2226ee7
1 parent d5dcbfb
commit 2226ee7
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Showing 9 changed files with 424 additions and 563 deletions.
diff --git a/parser/gen/CEL.g4 b/parser/gen/CEL.g4
@@ -14,8 +14,6 @@
 
 grammar CEL;
 
-// Note: grammar here should be rather final, but lexis is a moving target.
-
 // Grammar Rules
 // =============
 
@@ -93,11 +91,6 @@ literal
 // Lexer Rules
 // ===========
 
-// TODO(b/63180832): align implementation with spec at go/api-expr/langdef.md.
-//   At this point, it would be premature to do this as the spec is still a moving
-//   target. The current rules were c&p from some other code in google3, and are
-//   only approximative.
-
 EQUALS : '==';
 NOT_EQUALS : '!=';
 LESS : '<';
@@ -127,31 +120,35 @@ TRUE : 'true';
 FALSE : 'false';
 NULL : 'null';
 
-fragment EXPONENT : ('e' | 'E') ( '+' | '-' )? DIGIT+ ;
-fragment DIGIT  : '0'..'9' ;
+fragment BACKSLASH : '\\';
 fragment LETTER : 'A'..'Z' | 'a'..'z' ;
+fragment DIGIT  : '0'..'9' ;
+fragment EXPONENT : ('e' | 'E') ( '+' | '-' )? DIGIT+ ;
 fragment HEXDIGIT : ('0'..'9'|'a'..'f'|'A'..'F') ;
-fragment OCTDIGIT : '0'..'7' ;
+fragment RAW : 'r' | 'R';
 
-// TODO: Ensure escape sequences mirror those supported in Google SQL.
 fragment ESC_SEQ
-    : '\\' ~('0'..'9'|'a'..'f'|'A'..'F' | '\r' | '\n' | '\t' | 'u')
-    | UNI_SEQ
-    | OCT_SEQ
+    : ESC_CHAR_SEQ
+    | ESC_BYTE_SEQ
+    | ESC_UNI_SEQ
+    | ESC_OCT_SEQ
+    ;
+
+fragment ESC_CHAR_SEQ
+    : BACKSLASH ('a'|'b'|'f'|'n'|'r'|'t'|'v'|'"'|'\''|'\\'|'?'|'`')
     ;
 
-fragment SPECIAL_ESC_CHAR
-    : ('b'|'t'|'n'|'f'|'r'|'\"'|'\''|'\\')
+fragment ESC_OCT_SEQ
+    : BACKSLASH ('0'..'3') ('0'..'7') ('0'..'7')
     ;
 
-fragment OCT_SEQ
-    : '\\' ('0'..'3') ('0'..'7') ('0'..'7')
-    | '\\' ('0'..'7') ('0'..'7')
-    | '\\' ('0'..'7')
+fragment ESC_BYTE_SEQ
+    : BACKSLASH ( 'x' | 'X' ) HEXDIGIT HEXDIGIT
     ;
 
-fragment UNI_SEQ
-    : '\\' 'u' HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT
+fragment ESC_UNI_SEQ
+    : BACKSLASH 'u' HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT
+    | BACKSLASH 'U' HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT HEXDIGIT
     ;
 
 WHITESPACE : ( '\t' | ' ' | '\r' | '\n'| '\u000C' )+ -> channel(HIDDEN) ;
@@ -173,8 +170,8 @@ NUM_UINT
    ;
 
 STRING
-  : '"' (ESC_SEQ | ~('"'|'\n'|'\r'))* '"'
-  | '\'' (ESC_SEQ | ~('\''|'\n'|'\r'))* '\''
+  : '"' (ESC_SEQ | ~('\\'|'"'|'\n'|'\r'))* '"'
+  | '\'' (ESC_SEQ | ~('\\'|'\''|'\n'|'\r'))* '\''
   | '"""' (ESC_SEQ | ~('\\'))*? '"""'
   | '\'\'\'' (ESC_SEQ | ~('\\'))*? '\'\'\''
   | RAW '"' ~('"'|'\n'|'\r')* '"'
@@ -183,8 +180,6 @@ STRING
   | RAW '\'\'\'' .*? '\'\'\''
   ;
 
-fragment RAW : 'r' | 'R';
-
 BYTES : ('b' | 'B') STRING;
 
-IDENTIFIER : (LETTER | '_') ( LETTER | DIGIT | '_')*;
+IDENTIFIER : (LETTER | '_') ( LETTER | DIGIT | '_')*;
diff --git a/parser/gen/cel_base_listener.go b/parser/gen/cel_base_listener.go
@@ -1,18 +1,4 @@
-// Copyright 2018 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Generated from /Users/ozben/go/src/celgo/bin/../parser/gen/CEL.g4 by ANTLR 4.7.
+// Generated from /Users/tswadell/lace/go/src/github.com/google/cel-go/bin/../parser/gen/CEL.g4 by ANTLR 4.7.
 
 package gen // CEL
 import "github.com/antlr/antlr4/runtime/Go/antlr"
@@ -118,12 +104,6 @@ func (s *BaseCELListener) EnterIdentOrGlobalCall(ctx *IdentOrGlobalCallContext)
 // ExitIdentOrGlobalCall is called when production IdentOrGlobalCall is exited.
 func (s *BaseCELListener) ExitIdentOrGlobalCall(ctx *IdentOrGlobalCallContext) {}
 
-// EnterDeprecatedIn is called when production DeprecatedIn is entered.
-func (s *BaseCELListener) EnterDeprecatedIn(ctx *DeprecatedInContext) {}
-
-// ExitDeprecatedIn is called when production DeprecatedIn is exited.
-func (s *BaseCELListener) ExitDeprecatedIn(ctx *DeprecatedInContext) {}
-
 // EnterNested is called when production Nested is entered.
 func (s *BaseCELListener) EnterNested(ctx *NestedContext) {}
 

diff --git a/parser/gen/cel_base_visitor.go b/parser/gen/cel_base_visitor.go
@@ -1,18 +1,4 @@
-// Copyright 2018 Google LLC
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// Generated from /Users/ozben/go/src/celgo/bin/../parser/gen/CEL.g4 by ANTLR 4.7.
+// Generated from /Users/tswadell/lace/go/src/github.com/google/cel-go/bin/../parser/gen/CEL.g4 by ANTLR 4.7.
 
 package gen // CEL
 import "github.com/antlr/antlr4/runtime/Go/antlr"
@@ -77,10 +63,6 @@ func (v *BaseCELVisitor) VisitIdentOrGlobalCall(ctx *IdentOrGlobalCallContext) i
 	return v.VisitChildren(ctx)
 }
 
-func (v *BaseCELVisitor) VisitDeprecatedIn(ctx *DeprecatedInContext) interface{} {
-	return v.VisitChildren(ctx)
-}
-
 func (v *BaseCELVisitor) VisitNested(ctx *NestedContext) interface{} {
 	return v.VisitChildren(ctx)
 }