diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/lexer.js | 1 | ||||
-rw-r--r-- | src/parser.js | 14 |
2 files changed, 15 insertions, 0 deletions
diff --git a/src/lexer.js b/src/lexer.js index 85579fb..fd0d0a3 100644 --- a/src/lexer.js +++ b/src/lexer.js @@ -25,6 +25,7 @@ newLexemeType('-', '-') newLexemeType('(', '\\(') newLexemeType(')', '\\)') newLexemeType('E', 'E') +newLexemeType('K', 'K') newSkippableLexeme('whitespace', '\\s+') const lex = (expressionString) => { diff --git a/src/parser.js b/src/parser.js index 9479abc..5e9960a 100644 --- a/src/parser.js +++ b/src/parser.js @@ -6,6 +6,8 @@ let throwSyntaxError = () => { throw new Error('Syntax error: unexpected token') } +const dieBindingPower = 30 + let newSymbol = (type, nud, lbp, led) => { symbols[type] = { type, @@ -33,6 +35,16 @@ newSymbol('(', function(parser) { newSymbol(')') +const newDieOperation = (symbol, nud = null) => { + newSymbol(symbol, nud, dieBindingPower, (left, parser) => { + return { + type: symbol, + left: left, + right: parser.expression(dieBindingPower - 1) + } + }) +} + newSymbol('d', (parser) => { return { type: 'd', @@ -55,6 +67,8 @@ newSymbol('E', null, 30, (left, parser) => { } }) +newDieOperation('K') + newSymbol('+', null, 20, (left, parser) => { return { type: 'add', |