Clarify that lexing is greedy

At a glance

• Identifier: #599
• Stage: RFC3: Accepted
• Champion: @leebyron
• PR: Clarify that lexing is greedy

Timeline

• Added to 2019-10-10 WG agenda
• Mentioned in 2019-10-10 WG notes
• Added to 2019-09-12 WG agenda
• Mentioned in 2019-09-12 WG notes
• Added to 2019-08-01 WG agenda
• Spec PR created on 2019-07-23 by leebyron
• Commit pushed: Clarify lexing is greedy with lookahead restrictions. on 2019-07-23 by @leebyron

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GraphQL syntactical grammars intend to be unambiguous. While lexical grammars should also be - there has historically been an assumption that lexical parsing is greedy. This is obvious for numbers and words, but less obvious for empty block strings.

Either way, the additional clarity removes ambiguity from the spec

Partial fix for #564 Fixes #572

Specifically addresses https://github.com/graphql/graphql-spec/pull/564#issuecomment-508714529