PEG Linter ー peglint ref: http://qiita.com/yhirose/items/322d5e81d98de7e7df9e

calc.peg

Expr    ← Sum
Sum     ← Product (('+' / '-') Product)*
Product ← Value (('*' / '/') Value)*
Value   ← [0-9]+ / '(' Expr ')'

calc2.peg

$ peglint calc2.peg
1:17 'Hello' is not defined.

calc3.peg

# 構文ルール
Expr    ← Sum
Sum     ← Product (SumOpe Product)*
Product ← Value (ProOpe Value)*
Value   ← Number / '(' Expr ')'

# 字句ルール
SumOpe  ← ('+' / '-')
ProOpe  ← ('*' / '/')
Number  ← [0-9]+

file0.txt

$ go get github.com/yhirose/go-peg/cmd/peglint

file10.txt

$ peglint -s "2*(3+5)/4" -trace calc3.peg
pos:lev rule/ope
------- --------
0:0 [Expr]
0:1   reference
0:2     [Sum]
0:3       sequence
0:4         reference
0:5           [Product]
0:6             sequence
0:7               reference
0:8                 [Value]
0:9                   prioritizedChoice
0:10                        reference
0:11                          [Number]
0:12                            oneOrMore
0:13                              characterClass
1:13                              characterClass
1:7               zeroOrMore
1:8                 sequence
1:9                   reference
1:10                        [ProOpe]
1:11                          prioritizedChoice
1:12                            literalString
2:9                   reference
2:10                        [Value]
2:11                          prioritizedChoice

[以下に続く...]

file2.txt

$ peglint calc.peg

file3.txt

Expr    ← Sum Hello
Sum     ← Product (('+' / '-') Product)*
Product ← Value (('*' / '/') Value)*
Value   ← [0-9]+ / '(' Expr ')'

file5.txt

$ peglint -s "2*(3+5)/4" calc.peg
$ peglint -s "(hello world)" calc.peg
1:2 syntax error

file6.txt

$ peglint -s "2*(3+5)/4" -ast calc.peg
+ Expr
  + Sum
    + Product
      + Value
      + Value
        + Expr
          + Sum
            + Product
              + Value
            + Product
              + Value
      + Value

file7.txt

$ peglint -s "2*(3+5)/4" -ast -opt calc.peg
+ Product
  + Value
  + Sum
    + Value
    + Value
  + Value

file9.txt

 ~/Dropbox/Projects/go-peg-tutorial$ peglint -s "2*(3+5)/4" -ast -opt calc3.peg 
+ Product
  - Number ("2")
  - ProOpe ("*")
  + Sum
    - Number ("3")
    - SumOpe ("+")
    - Number ("5")
  - ProOpe ("/")
  - Number ("4")