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9 | function stripFunctionStart(input) {
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10 | const BEGIN = 1;
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11 | const LBRACE = 2;
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12 | const EQ = 4;
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13 | const ARROW = 8;
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14 | const ARROW_LBRACE = 16;
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15 | const ARROW_PAREN = 32;
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16 | const DONE = 64;
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17 |
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18 | const isWhitespace = ch => ch === ' ' || ch === '\t' || ch === '\n';
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19 |
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20 | const nextState = (state, c) => {
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21 | switch (state) {
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22 | case BEGIN:
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23 | switch (c) {
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24 | case '{':
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25 | return LBRACE;
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26 | case '=':
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27 | return EQ;
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28 | default:
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29 | return BEGIN;
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30 | }
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31 |
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32 | case LBRACE:
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33 | return c === ' ' ? LBRACE : DONE;
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34 |
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35 | case EQ:
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36 | return c === '>' ? ARROW : BEGIN;
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37 |
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38 | case ARROW:
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39 | if (isWhitespace(c)) return ARROW;
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40 | switch (c) {
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41 | case '{':
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42 | return ARROW_LBRACE;
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43 | case '(':
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44 | return ARROW_PAREN;
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45 | default:
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46 | return DONE;
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47 | }
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48 |
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49 | case ARROW_LBRACE:
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50 | case ARROW_PAREN:
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51 | return DONE;
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52 | }
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53 | };
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54 |
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55 | let state = BEGIN;
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56 | let pos = 0;
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57 | while (pos < input.length && state !== DONE) {
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58 | state = nextState(state, input.charAt(pos));
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59 | pos += 1;
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60 | }
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61 | return state === DONE ? input.slice(pos - 1) : input;
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62 | }
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63 |
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64 | module.exports = stripFunctionStart;
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