custom integer literals (#17489)

* user defined integer literals; refs #17020
* updated renderer.nim
* use mlexerutils helper
* imported all test cases from https://github.com/nim-lang/Nim/pull/17020
* final grammar updated

tests/lexer/tcustom_numeric_literals.nim

@@ -0,0 +1,150 @@
+discard """
+  targets: "c cpp js"
+"""
+
+# Test tkStrNumLit
+
+import std/[macros, strutils]
+import mlexerutils
+
+# AST checks
+
+assertAST dedent """
+  StmtList
+    ProcDef
+      AccQuoted
+        Ident "\'"
+        Ident "wrap"
+      Empty
+      Empty
+      FormalParams
+        Ident "string"
+        IdentDefs
+          Ident "number"
+          Ident "string"
+          Empty
+      Empty
+      Empty
+      StmtList
+        Asgn
+          Ident "result"
+          Infix
+            Ident "&"
+            Infix
+              Ident "&"
+              StrLit "[["
+              Ident "number"
+            StrLit "]]"""":
+  proc `'wrap`(number: string): string =
+    result = "[[" & number & "]]"
+
+assertAST dedent """
+  StmtList
+    DotExpr
+      RStrLit "-38383839292839283928392839283928392839283.928493849385935898243e-50000"
+      Ident "\'wrap"""":
+  -38383839292839283928392839283928392839283.928493849385935898243e-50000'wrap
+
+proc `'wrap`(number: string): string = "[[" & number & "]]"
+doAssert lispReprStr(-1'wrap) == """(DotExpr (RStrLit "-1") (Ident "\'wrap"))"""
+
+template main =
+  block: # basic suffix usage
+    template `'twrap`(number: string): untyped =
+      number.`'wrap`
+    proc extraContext(): string =
+      22.40'wrap
+    proc `*`(left, right: string): string =
+      result = left & "times" & right
+    proc `+`(left, right: string): string =
+      result = left & "plus" & right
+
+    doAssert 1'wrap == "[[1]]"
+    doAssert -1'wrap == "[[-1]]":
+      "unable to resolve a negative integer-suffix pattern"
+    doAssert 12345.67890'wrap == "[[12345.67890]]"
+    doAssert 1'wrap*1'wrap == "[[1]]times[[1]]":
+      "unable to resolve an operator between two suffixed numeric literals"
+    doAssert 1'wrap+ -1'wrap == "[[1]]plus[[-1]]":  # will generate a compiler warning about inconsistent spacing
+      "unable to resolve a negative suffixed numeric literal following an operator"
+    doAssert 1'wrap + -1'wrap == "[[1]]plus[[-1]]"
+    doAssert 1'twrap == "[[1]]"
+    doAssert extraContext() == "[[22.40]]":
+      "unable to return a suffixed numeric literal by an implicit return"
+    doAssert 0x5a3a'wrap == "[[0x5a3a]]"
+    doAssert 0o5732'wrap == "[[0o5732]]"
+    doAssert 0b0101111010101'wrap == "[[0b0101111010101]]"
+    doAssert -38383839292839283928392839283928392839283.928493849385935898243e-50000'wrap == "[[-38383839292839283928392839283928392839283.928493849385935898243e-50000]]"
+    doAssert 1234.56'wrap == "[[1234.56]]":
+      "unable to properly account for context with suffixed numeric literals"
+
+  block: # verify that the i64, f32, etc builtin suffixes still parse correctly
+    const expectedF32: float32 = 123.125
+    proc `'f9`(number: string): string =   # proc starts with 'f' just like 'f32'
+      "[[" & number & "]]"
+    proc `'f32a`(number: string): string =   # looks even more like 'f32'
+      "[[" & number & "]]"
+    proc `'d9`(number: string): string =   # proc starts with 'd' just like the d suffix
+      "[[" & number & "]]"
+    proc `'i9`(number: string): string =   # proc starts with 'i' just like 'i64'
+      "[[" & number & "]]"
+    proc `'u9`(number: string): string =   # proc starts with 'u' just like 'u8'
+      "[[" & number & "]]"
+
+    doAssert 123.125f32 == expectedF32:
+      "failing to support non-quoted legacy f32 floating point suffix"
+    doAssert 123.125'f32 == expectedF32
+    doAssert 123.125e0'f32 == expectedF32
+    doAssert 1234.56'wrap == 1234.56'f9
+    doAssert 1234.56'wrap == 1234.56'f32a
+    doAssert 1234.56'wrap == 1234.56'd9
+    doAssert 1234.56'wrap == 1234.56'i9
+    doAssert 1234.56'wrap == 1234.56'u9
+    doAssert lispReprStr(1234.56'u9) == """(DotExpr (RStrLit "1234.56") (Ident "\'u9"))""":
+      "failed to properly build AST for suffix that starts with u"
+    doAssert -128'i8 == (-128).int8
+
+  block: # case checks
+    doAssert 1E2 == 100:
+      "lexer not handling upper-case exponent"
+    doAssert 1.0E2 == 100.0
+    doAssert 1e2 == 100
+    doAssert 0xdeadBEEF'wrap == "[[0xdeadBEEF]]":
+      "lexer not maintaining original case"
+    doAssert 0.1E12'wrap == "[[0.1E12]]"
+    doAssert 0.0e12'wrap == "[[0.0e12]]"
+    doAssert 0.0e+12'wrap == "[[0.0e+12]]"
+    doAssert 0.0e-12'wrap == "[[0.0e-12]]"
+    doAssert 0e-12'wrap == "[[0e-12]]"
+
+  block: # macro and template usage
+    template `'foo`(a: string): untyped = (a, 2)
+    doAssert -12'foo == ("-12", 2)
+    template `'fooplus`(a: string, b: int): untyped = (a, b)
+    doAssert -12'fooplus(2) == ("-12", 2)
+    template `'fooplusopt`(a: string, b: int = 99): untyped = (a, b)
+    doAssert -12'fooplusopt(2) == ("-12", 2)
+    doAssert -12'fooplusopt() == ("-12", 99)
+    doAssert -12'fooplusopt == ("-12", 99)
+    macro `'bar`(a: static string): untyped =
+      var infix = newNimNode(nnkInfix)
+      infix.add newIdentNode("&")
+      infix.add newLit("got ")
+      infix.add newLit(a.repr)
+      result = newNimNode(nnkStmtList)
+      result.add infix
+    doAssert -12'bar == "got \"-12\""
+    macro deb(a): untyped = newLit(a.repr)
+    doAssert deb(-12'bar) == "-12'bar"
+    # macro metawrap(): untyped =
+    #   func wrap1(a: string): string = "{" & a & "}"
+    #   func `'wrap2`(a: string): string = "{" & a & "}"
+    #   result = quote do:
+    #     let a1 = wrap1"-128"
+    #     let a2 = -128'wrap2
+    # metawrap()
+    # doAssert a1 == "{-128}"
+    # doAssert a2 == "{-128}"
+
+static: main()
+main()