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PEG.js grammar file for basic math
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| start = Term_AddSub | |
| // ===== Add/Sub Term ===== | |
| Term_AddSub = s:Term_MulDiv v:(Add / Sub)* | |
| { for(var r = s, i=0; i<v.length; i++){ r += v[i]; }; return r; } | |
| Add = "+" v:Term_MulDiv | |
| { return v; } | |
| Sub = "-" v:Term_MulDiv | |
| { return -1 * v; } | |
| // ===== Mult/Div Term ===== | |
| Term_MulDiv = s:Term_Exp v:(Mul / Div)* | |
| { for(var r = s, i=0; i<v.length; i++){ r *= v[i]; } return r; } | |
| Mul = "*" v:Term_Exp | |
| { return v; } | |
| Div = "/" v:Term_Exp | |
| { return 1 / v; } | |
| // ===== Exp Term ===== | |
| Term_Exp = s:Primary v:(Exp)* | |
| { for(var r = s, i=0; i<v.length; i++){ r = Math.pow(r, v[i]); }; return r; } | |
| Exp = "^" v:Primary | |
| { return v; } | |
| // ====== Primary ==== | |
| Primary = (Parens / Neg / Number ) | |
| Parens = "(" v:Term_AddSub ")" | |
| { return v; } | |
| Neg = "-" v:Primary | |
| { return -1* v; } | |
| Number = digits:([0-9]+) | |
| { return parseInt(digits.join(""), 10); } |
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