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jashkenas--coffeescript/test/numbers.coffee
Simon Lydell 021d2e4376 Refactor Literal into several subtypes
Previously, the parser created `Literal` nodes for many things. This resulted in
information loss. Instead of being able to check the node type, we had to use
regexes to tell the different types of `Literal`s apart. That was a bit like
parsing literals twice: Once in the lexer, and once (or more) in the compiler.
It also caused problems, such as `` `this` `` and `this` being indistinguishable
(fixes #2009).

Instead returning `new Literal` in the grammar, subtypes of it are now returned
instead, such as `NumberLiteral`, `StringLiteral` and `IdentifierLiteral`. `new
Literal` by itself is only used to represent code chunks that fit no category.
(While mentioning `NumberLiteral`, there's also `InfinityLiteral` now, which is
a subtype of `NumberLiteral`.)

`StringWithInterpolations` has been added as a subtype of `Parens`, and
`RegexWithInterpolations` as a subtype of `Call`. This makes it easier for other
programs to make use of CoffeeScript's "AST" (nodes). For example, it is now
possible to distinguish between `"a #{b} c"` and `"a " + b + " c"`. Fixes #4192.

`SuperCall` has been added as a subtype of `Call`.

Note, though, that some information is still lost, especially in the lexer. For
example, there is no way to distinguish a heredoc from a regular string, or a
heregex without interpolations from a regular regex. Binary and octal number
literals are indistinguishable from hexadecimal literals.

After the new subtypes were added, they were taken advantage of, removing most
regexes in nodes.coffee. `SIMPLENUM` (which matches non-hex integers) had to be
kept, though, because such numbers need special handling in JavaScript (for
example in `1..toString()`).

An especially nice hack to get rid of was using `new String()` for the token
value for reserved identifiers (to be able to set a property on them which could
survive through the parser). Now it's a good old regular string.

In range literals, slices, splices and for loop steps when number literals
are involved, CoffeeScript can do some optimizations, such as precomputing the
value of, say, `5 - 3` (outputting `2` instead of `5 - 3` literally). As a side
bonus, this now also works with hexadecimal number literals, such as `0x02`.

Finally, this also improves the output of `coffee --nodes`:

    # Before:
    $ bin/coffee -ne 'while true
      "#{a}"
      break'
    Block
      While
        Value
          Bool
        Block
          Value
            Parens
              Block
                Op +
                  Value """"
                  Value
                    Parens
                      Block
                        Value "a" "break"

    # After:
    $ bin/coffee -ne 'while true
      "#{a}"
      break'
    Block
      While
        Value BooleanLiteral: true
        Block
          Value
            StringWithInterpolations
              Block
                Op +
                  Value StringLiteral: ""
                  Value
                    Parens
                      Block
                        Value IdentifierLiteral: a
          StatementLiteral: break
2016-03-05 17:08:11 +01:00

85 lines
2.1 KiB
CoffeeScript

# Number Literals
# ---------------
# * Decimal Integer Literals
# * Octal Integer Literals
# * Hexadecimal Integer Literals
# * Scientific Notation Integer Literals
# * Scientific Notation Non-Integer Literals
# * Non-Integer Literals
# * Binary Integer Literals
# Binary Integer Literals
# Binary notation is understood as would be decimal notation.
test "Parser recognises binary numbers", ->
eq 4, 0b100
# Decimal Integer Literals
test "call methods directly on numbers", ->
eq 4, 4.valueOf()
eq '11', 4.toString 3
eq -1, 3 -4
#764: Numbers should be indexable
eq Number::toString, 42['toString']
eq Number::toString, 42.toString
eq Number::toString, 2e308['toString'] # Infinity
# Non-Integer Literals
# Decimal number literals.
value = .25 + .75
ok value is 1
value = 0.0 + -.25 - -.75 + 0.0
ok value is 0.5
#764: Numbers should be indexable
eq Number::toString, 4['toString']
eq Number::toString, 4.2['toString']
eq Number::toString, .42['toString']
eq Number::toString, (4)['toString']
eq Number::toString, 4.toString
eq Number::toString, 4.2.toString
eq Number::toString, .42.toString
eq Number::toString, (4).toString
test '#1168: leading floating point suppresses newline', ->
eq 1, do ->
1
.5 + 0.5
test "Python-style octal literal notation '0o777'", ->
eq 511, 0o777
eq 1, 0o1
eq 1, 0o00001
eq parseInt('0777', 8), 0o777
eq '777', 0o777.toString 8
eq 4, 0o4.valueOf()
eq Number::toString, 0o777['toString']
eq Number::toString, 0o777.toString
test "#2060: Disallow uppercase radix prefixes and exponential notation", ->
for char in ['b', 'o', 'x', 'e']
program = "0#{char}0"
doesNotThrow -> CoffeeScript.compile program, bare: yes
throws -> CoffeeScript.compile program.toUpperCase(), bare: yes
test "#2224: hex literals with 0b or B or E", ->
eq 176, 0x0b0
eq 177, 0x0B1
eq 225, 0xE1
test "Infinity", ->
eq Infinity, CoffeeScript.eval "0b#{Array(1024 + 1).join('1')}"
eq Infinity, CoffeeScript.eval "0o#{Array(342 + 1).join('7')}"
eq Infinity, CoffeeScript.eval "0x#{Array(256 + 1).join('f')}"
eq Infinity, CoffeeScript.eval Array(500 + 1).join('9')
eq Infinity, 2e308