Merge pull request #157 from kaushalmodi/nim_underscore

Allow standalone _ to be recognized as identifier in Nim

lexers/n/nim.go

@@ -31,6 +31,7 @@ var Nim = internal.Register(MustNewLexer(
 			{`(v_?a_?r)\b`, KeywordDeclaration, nil},
 			{`(i_?n_?t_?|i_?n_?t_?8_?|i_?n_?t_?1_?6_?|i_?n_?t_?3_?2_?|i_?n_?t_?6_?4_?|f_?l_?o_?a_?t_?|f_?l_?o_?a_?t_?3_?2_?|f_?l_?o_?a_?t_?6_?4_?|b_?o_?o_?l_?|c_?h_?a_?r_?|r_?a_?n_?g_?e_?|a_?r_?r_?a_?y_?|s_?e_?q_?|s_?e_?t_?|s_?t_?r_?i_?n_?g_?)\b`, KeywordType, nil},
 			{`(n_?i_?l_?|t_?r_?u_?e_?|f_?a_?l_?s_?e_?)\b`, KeywordPseudo, nil},
+			{`\b_\b`, Name, nil}, // Standalone _ used as discardable variable identifier
 			{`\b((?![_\d])\w)(((?!_)\w)|(_(?!_)\w))*`, Name, nil},
 			{`[0-9][0-9_]*(?=([e.]|\'f(32|64)))`, LiteralNumberFloat, Push("float-suffix", "float-number")},
 			{`0x[a-f0-9][a-f0-9_]*`, LiteralNumberHex, Push("int-suffix")},

lexers/testdata/nim.actual

@@ -0,0 +1,7 @@
+# -*- nim -*-
+import random
+proc randBool(): bool =
+  randomize()
+  result = rand(1).bool
+for _ in 0..5:
+  echo randBool()

lexers/testdata/nim.expected

@@ -0,0 +1,45 @@
+[
+  {"type":"Comment","value":"# -*- nim -*-"},
+  {"type":"Text","value":"\n"},
+  {"type":"KeywordNamespace","value":"import"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"random"},
+  {"type":"Text","value":"\n"},
+  {"type":"Keyword","value":"proc "},
+  {"type":"NameFunction","value":"randBool"},
+  {"type":"Punctuation","value":"():"},
+  {"type":"Text","value":" "},
+  {"type":"KeywordType","value":"bool"},
+  {"type":"Text","value":" "},
+  {"type":"Operator","value":"="},
+  {"type":"Text","value":"\n  "},
+  {"type":"Name","value":"randomize"},
+  {"type":"Punctuation","value":"()"},
+  {"type":"Text","value":"\n  "},
+  {"type":"Name","value":"result"},
+  {"type":"Text","value":" "},
+  {"type":"Operator","value":"="},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"rand"},
+  {"type":"Punctuation","value":"("},
+  {"type":"LiteralNumberInteger","value":"1"},
+  {"type":"Punctuation","value":")."},
+  {"type":"KeywordType","value":"bool"},
+  {"type":"Text","value":"\n"},
+  {"type":"Keyword","value":"for"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"_"},
+  {"type":"Text","value":" "},
+  {"type":"OperatorWord","value":"in"},
+  {"type":"Text","value":" "},
+  {"type":"LiteralNumberFloat","value":"0"},
+  {"type":"Punctuation","value":".."},
+  {"type":"LiteralNumberInteger","value":"5"},
+  {"type":"Punctuation","value":":"},
+  {"type":"Text","value":"\n  "},
+  {"type":"Name","value":"echo"},
+  {"type":"Text","value":" "},
+  {"type":"Name","value":"randBool"},
+  {"type":"Punctuation","value":"()"},
+  {"type":"Text","value":"\n"}
+]