FParsec identifiers vs keywords

Question

For languages with keywords, some special trickery needs to happen to prevent for example \"if\" from being interpreted as an identifier and \"ifSomeVariableName\" from beco

Answer 1

You can define a parser for whitespace and check if keyword or identifier is followed by it. For example some generic whitespace parser will look like

let pWhiteSpace = pLineComment <|> pMultilineComment <|> pSpaces

this will require at least one whitespace

let ws1 = skipMany1 pWhiteSpace

then if will look like

let pIf = pstring "if" .>> ws1