glsl-parser

glsl-parser

A GLSL parser that takes tokens from glsl-tokenizer and turns them into an AST.

May either be used synchronously or as a stream.

API

stream = require('glsl-parser/stream')

Creates a GLSL parser stream, which emits nodes as they're parsed.

var TokenStream = require('glsl-tokenizer/stream')
var ParseStream = require('glsl-parser/stream')
var fs = require('fs')

fs.createReadStream('test.glsl')
  .pipe(TokenStream())
  .pipe(ParseStream())
  .on('data', function(x) {
    console.log('ast of', x.type)
  })

ast = stream.program

The full program's AST, which will be updated with each incoming token.

ast = require('glsl-parser/direct')(tokens)

Synchronously parses an array of tokens from glsl-tokenizer.

var TokenString = require('glsl-tokenizer/string')
var ParseTokens = require('glsl-parser/direct')
var fs = require('fs')

var src = fs.readFileSync('test.glsl', 'utf8')
var tokens = TokenString(src)
var ast = ParseTokens(tokens)

console.log(ast)

Nodes

• stmtlist
• stmt
• struct
• function
• functionargs
• decl
• decllist
• forloop
• whileloop
• if
• expr
• precision
• comment
• preprocessor
• keyword
• ident
• return
• continue
• break
• discard
• do-while
• binary
• ternary
• unary

Known Issues

• because i am not smart enough to write a fully streaming parser, the current parser "cheats" a bit when it encounters a expr node! it actually waits until it has all the tokens it needs to build a tree for a given expression, then builds it and emits the constituent child nodes in the expected order. the expr parsing is heavily influenced by crockford's tdop article. the rest of the parser is heavily influenced by fever dreams.

• the parser might hit a state where it's looking at what could be an expression, or it could be a declaration -- that is, the statement starts with a previously declared struct. it'll opt to pretend it's a declaration, but that might not be the case -- it might be a user-defined constructor starting a statement!

• "unhygenic" #if / #endif macros are completely unhandled at the moment, since they're a bit of a pain. if you've got unhygenic macros in your code, move the #if / #endifs to statement level, and have them surround wholly parseable code. this sucks, and i am sorry.

License

MIT, see LICENSE.md for more details.