refactor(parser): re-introduce calls to then, and recover from errors in with conditions. (VirusTotal#578)

Using `then` is required to avoid the parser from going deep into syntax rules when it already failed, however readability was improved by removing unnecessary closures.

Also, the parser is now able to recover from errors inside the condition of `with` statements.

Author: plusvic

parser/src/parser/mod.rs

@@ -7,7 +7,6 @@ Token { kind: WHITESPACE, span: Span(9..10) }
 Token { kind: L_BRACE, span: Span(10..11) }
 Begin { kind: ERROR, span: Span(11..56) }
 Token { kind: L_BRACE, span: Span(11..12) }
-Error { message: "expecting `meta`, `strings` or `condition`, found `{`", span: Span(11..12) }
 Token { kind: NEWLINE, span: Span(12..13) }
 Token { kind: WHITESPACE, span: Span(13..15) }
 Token { kind: META_KW, span: Span(15..19) }
@@ -30,4 +29,5 @@ End { kind: ERROR, span: Span(11..56) }
 Token { kind: NEWLINE, span: Span(56..57) }
 Token { kind: R_BRACE, span: Span(57..58) }
 End { kind: RULE_DECL, span: Span(0..58) }
+Error { message: "expecting `meta`, `strings` or `condition`, found `{`", span: Span(11..12) }
 End { kind: SOURCE_FILE, span: Span(0..58) }

parser/src/parser/tests/testdata/basic-error-1.cststream

@@ -21,7 +21,6 @@ End { kind: ERROR, span: Span(14..32) }
 Token { kind: WHITESPACE, span: Span(32..33) }
 Begin { kind: ERROR, span: Span(33..37) }
 Token { kind: UNKNOWN, span: Span(33..37) }
-Error { message: "unclosed literal string", span: Span(33..37) }
 End { kind: ERROR, span: Span(33..37) }
 Token { kind: NEWLINE, span: Span(37..38) }
 Token { kind: WHITESPACE, span: Span(38..40) }
@@ -39,4 +38,5 @@ End { kind: CONDITION_BLK, span: Span(40..60) }
 Token { kind: NEWLINE, span: Span(60..61) }
 Token { kind: R_BRACE, span: Span(61..62) }
 End { kind: RULE_DECL, span: Span(0..62) }
+Error { message: "unclosed literal string", span: Span(33..37) }
 End { kind: SOURCE_FILE, span: Span(0..62) }

parser/src/parser/tests/testdata/basic-error-2.cststream

@@ -1,15 +1,14 @@
 SOURCE_FILE@0..26
-  RULE_DECL@0..26
+  ERROR@0..26
     RULE_KW@0..4 "rule"
-    ERROR@4..24
-      L_BRACE@4..5 "{"
-      NEWLINE@5..6 "\n"
-      WHITESPACE@6..7 "\t"
-      CONDITION_KW@7..16 "condition"
-      COLON@16..17 ":"
-      NEWLINE@17..18 "\n"
-      WHITESPACE@18..20 "\t\t"
-      TRUE_KW@20..24 "true"
+    L_BRACE@4..5 "{"
+    NEWLINE@5..6 "\n"
+    WHITESPACE@6..7 "\t"
+    CONDITION_KW@7..16 "condition"
+    COLON@16..17 ":"
+    NEWLINE@17..18 "\n"
+    WHITESPACE@18..20 "\t\t"
+    TRUE_KW@20..24 "true"
     NEWLINE@24..25 "\n"
     R_BRACE@25..26 "}"
 

parser/src/parser/tests/testdata/basic-error-4.cst

@@ -1,18 +1,16 @@
 Begin { kind: SOURCE_FILE, span: Span(0..26) }
-Begin { kind: RULE_DECL, span: Span(0..26) }
+Begin { kind: ERROR, span: Span(0..26) }
 Token { kind: RULE_KW, span: Span(0..4) }
-Begin { kind: ERROR, span: Span(4..24) }
 Token { kind: L_BRACE, span: Span(4..5) }
-Error { message: "expecting identifier, found `{`", span: Span(4..5) }
 Token { kind: NEWLINE, span: Span(5..6) }
 Token { kind: WHITESPACE, span: Span(6..7) }
 Token { kind: CONDITION_KW, span: Span(7..16) }
 Token { kind: COLON, span: Span(16..17) }
 Token { kind: NEWLINE, span: Span(17..18) }
 Token { kind: WHITESPACE, span: Span(18..20) }
 Token { kind: TRUE_KW, span: Span(20..24) }
-End { kind: ERROR, span: Span(4..24) }
 Token { kind: NEWLINE, span: Span(24..25) }
 Token { kind: R_BRACE, span: Span(25..26) }
-End { kind: RULE_DECL, span: Span(0..26) }
+End { kind: ERROR, span: Span(0..26) }
+Error { message: "expecting identifier, found `{`", span: Span(4..5) }
 End { kind: SOURCE_FILE, span: Span(0..26) }

parser/src/parser/tests/testdata/basic-error-4.cststream

@@ -6,6 +6,6 @@ Token { kind: IDENT, span: Span(5..9) }
 Token { kind: WHITESPACE, span: Span(9..10) }
 Token { kind: L_BRACE, span: Span(10..11) }
 Token { kind: R_BRACE, span: Span(11..12) }
-Error { message: "expecting `meta`, `strings` or `condition`, found `}`", span: Span(11..12) }
 End { kind: RULE_DECL, span: Span(0..12) }
+Error { message: "expecting `meta`, `strings` or `condition`, found `}`", span: Span(11..12) }
 End { kind: SOURCE_FILE, span: Span(0..12) }

parser/src/parser/tests/testdata/basic-error-5.cststream

@@ -32,6 +32,6 @@ End { kind: ERROR, span: Span(30..33) }
 End { kind: CONDITION_BLK, span: Span(13..33) }
 Token { kind: NEWLINE, span: Span(33..34) }
 Token { kind: R_BRACE, span: Span(34..35) }
-Error { message: "expecting `(`, `[`, expression, `%`, operator, `of` or `}`, found `~`", span: Span(30..31) }
 End { kind: RULE_DECL, span: Span(0..35) }
+Error { message: "expecting `(`, `[`, expression, `%`, operator, `of` or `}`, found `~`", span: Span(30..31) }
 End { kind: SOURCE_FILE, span: Span(0..35) }

parser/src/parser/tests/testdata/bitwise-ops-error-1.cststream

@@ -34,8 +34,8 @@ End { kind: ERROR, span: Span(34..36) }
 End { kind: CONDITION_BLK, span: Span(15..36) }
 Token { kind: NEWLINE, span: Span(36..37) }
 Token { kind: R_BRACE, span: Span(37..38) }
-Error { message: "expecting expression or identifier, found `}`", span: Span(37..38) }
 End { kind: RULE_DECL, span: Span(0..38) }
+Error { message: "expecting expression or identifier, found `}`", span: Span(37..38) }
 Token { kind: NEWLINE, span: Span(38..39) }
 Token { kind: NEWLINE, span: Span(39..40) }
 Begin { kind: RULE_DECL, span: Span(40..81) }
@@ -74,8 +74,8 @@ End { kind: ERROR, span: Span(70..79) }
 End { kind: CONDITION_BLK, span: Span(55..79) }
 Token { kind: NEWLINE, span: Span(79..80) }
 Token { kind: R_BRACE, span: Span(80..81) }
-Error { message: "expecting expression or identifier, found `+`", span: Span(71..72) }
 End { kind: RULE_DECL, span: Span(40..81) }
+Error { message: "expecting expression or identifier, found `+`", span: Span(71..72) }
 Token { kind: NEWLINE, span: Span(81..82) }
 Token { kind: NEWLINE, span: Span(82..83) }
 Begin { kind: RULE_DECL, span: Span(83..121) }
@@ -111,8 +111,8 @@ End { kind: ERROR, span: Span(113..119) }
 End { kind: CONDITION_BLK, span: Span(98..119) }
 Token { kind: NEWLINE, span: Span(119..120) }
 Token { kind: R_BRACE, span: Span(120..121) }
-Error { message: "expecting expression or identifier, found `==`", span: Span(115..117) }
 End { kind: RULE_DECL, span: Span(83..121) }
+Error { message: "expecting expression or identifier, found `==`", span: Span(115..117) }
 Token { kind: NEWLINE, span: Span(121..122) }
 Token { kind: NEWLINE, span: Span(122..123) }
 Begin { kind: RULE_DECL, span: Span(123..167) }
@@ -154,8 +154,8 @@ End { kind: ERROR, span: Span(162..165) }
 End { kind: CONDITION_BLK, span: Span(138..165) }
 Token { kind: NEWLINE, span: Span(165..166) }
 Token { kind: R_BRACE, span: Span(166..167) }
-Error { message: "expecting expression, `%`, operator, `of` or `}`, found `(`", span: Span(162..163) }
 End { kind: RULE_DECL, span: Span(123..167) }
+Error { message: "expecting expression, `%`, operator, `of` or `}`, found `(`", span: Span(162..163) }
 Token { kind: NEWLINE, span: Span(167..168) }
 Token { kind: NEWLINE, span: Span(168..169) }
 Begin { kind: RULE_DECL, span: Span(169..250) }
@@ -213,7 +213,7 @@ End { kind: ERROR, span: Span(238..248) }
 End { kind: CONDITION_BLK, span: Span(214..248) }
 Token { kind: NEWLINE, span: Span(248..249) }
 Token { kind: R_BRACE, span: Span(249..250) }
-Error { message: "expecting operator or `}`, found `in`", span: Span(238..240) }
 End { kind: RULE_DECL, span: Span(169..250) }
+Error { message: "expecting operator or `}`, found `in`", span: Span(238..240) }
 Token { kind: NEWLINE, span: Span(250..251) }
 End { kind: SOURCE_FILE, span: Span(0..251) }

parser/src/parser/tests/testdata/expr-error-1.cststream

@@ -21,7 +21,6 @@ End { kind: ERROR, span: Span(13..29) }
 Token { kind: WHITESPACE, span: Span(29..30) }
 Begin { kind: ERROR, span: Span(30..43) }
 Token { kind: L_BRACE, span: Span(30..31) }
-Error { message: "expecting BYTE or `(`, found `)`", span: Span(40..41) }
 Token { kind: WHITESPACE, span: Span(31..32) }
 Token { kind: HEX_BYTE, span: Span(32..34) }
 Token { kind: WHITESPACE, span: Span(34..35) }
@@ -49,6 +48,7 @@ End { kind: CONDITION_BLK, span: Span(46..64) }
 Token { kind: NEWLINE, span: Span(64..65) }
 Token { kind: R_BRACE, span: Span(65..66) }
 End { kind: RULE_DECL, span: Span(0..66) }
+Error { message: "expecting BYTE or `(`, found `)`", span: Span(40..41) }
 Token { kind: NEWLINE, span: Span(66..67) }
 Token { kind: NEWLINE, span: Span(67..68) }
 Begin { kind: RULE_DECL, span: Span(68..124) }
@@ -73,7 +73,6 @@ End { kind: ERROR, span: Span(81..97) }
 Token { kind: WHITESPACE, span: Span(97..98) }
 Begin { kind: ERROR, span: Span(98..101) }
 Token { kind: L_BRACE, span: Span(98..99) }
-Error { message: "expecting BYTE or `(`, found `}`", span: Span(100..101) }
 Token { kind: WHITESPACE, span: Span(99..100) }
 Token { kind: R_BRACE, span: Span(100..101) }
 End { kind: ERROR, span: Span(98..101) }
@@ -93,4 +92,5 @@ End { kind: CONDITION_BLK, span: Span(104..122) }
 Token { kind: NEWLINE, span: Span(122..123) }
 Token { kind: R_BRACE, span: Span(123..124) }
 End { kind: RULE_DECL, span: Span(68..124) }
+Error { message: "expecting BYTE or `(`, found `}`", span: Span(100..101) }
 End { kind: SOURCE_FILE, span: Span(0..124) }

parser/src/parser/tests/testdata/hex-patterns-error-1.cststream

@@ -21,7 +21,6 @@ End { kind: ERROR, span: Span(13..29) }
 Token { kind: WHITESPACE, span: Span(29..30) }
 Begin { kind: ERROR, span: Span(30..35) }
 Token { kind: L_BRACE, span: Span(30..31) }
-Error { message: "expecting `[`, BYTE, `(` or `}`, found `0`", span: Span(33..34) }
 Token { kind: HEX_BYTE, span: Span(31..33) }
 Token { kind: INTEGER_LIT, span: Span(33..34) }
 Token { kind: R_BRACE, span: Span(34..35) }
@@ -42,6 +41,7 @@ End { kind: CONDITION_BLK, span: Span(38..56) }
 Token { kind: NEWLINE, span: Span(56..57) }
 Token { kind: R_BRACE, span: Span(57..58) }
 End { kind: RULE_DECL, span: Span(0..58) }
+Error { message: "expecting `[`, BYTE, `(` or `}`, found `0`", span: Span(33..34) }
 Token { kind: NEWLINE, span: Span(58..59) }
 Token { kind: NEWLINE, span: Span(59..60) }
 Begin { kind: RULE_DECL, span: Span(60..118) }
@@ -66,7 +66,6 @@ End { kind: ERROR, span: Span(73..89) }
 Token { kind: WHITESPACE, span: Span(89..90) }
 Begin { kind: ERROR, span: Span(90..95) }
 Token { kind: L_BRACE, span: Span(90..91) }
-Error { message: "expecting `[`, BYTE, `(` or `}`, found `a`", span: Span(93..94) }
 Token { kind: HEX_BYTE, span: Span(91..93) }
 Token { kind: IDENT, span: Span(93..94) }
 Token { kind: R_BRACE, span: Span(94..95) }
@@ -87,4 +86,5 @@ End { kind: CONDITION_BLK, span: Span(98..116) }
 Token { kind: NEWLINE, span: Span(116..117) }
 Token { kind: R_BRACE, span: Span(117..118) }
 End { kind: RULE_DECL, span: Span(60..118) }
+Error { message: "expecting `[`, BYTE, `(` or `}`, found `a`", span: Span(93..94) }
 End { kind: SOURCE_FILE, span: Span(0..118) }