HTML4 parser - lexer reached a stuck state

[Skyb0rg007]

Version

110.99.5 (Latest)

Operating System

• [X] Any
• [ ] Linux
• [ ] macOS
• [ ] Windows
• [ ] Other Unix

OS Version

No response

Processor

• [X] Any
• [ ] Arm (using Rosetta)
• [ ] PowerPC
• [ ] Sparc
• [ ] x86 (32-bit)
• [ ] x86-64 (64-bit)
• [ ] Other

System Component

SML/NJ Library

Severity

Minor

Description

The HTML4 lexer does not specify rules for all inputs

Transcript

- HTML4Parser.fromString "<";
uncaught exception Fail [Fail: lexer reached a stuck state]
  raised at: smlnj-lib/HTML4/html4.l.sml:94.46-94.80
             ml-lpt/lib/err-handler.sml:261.63

Expected Behavior

- HTML4Parser.fromString "<";
val it = NONE : html option

Note that this is what happens when you pass an incomplete tag such as "<x"

Steps to Reproduce

See transcript

Additional Information

The issue is in html4.l. There needs to be a case that handles "<" and "</" that are not followed by an alpha character or "!--".

Email address

skyler DOT soss AT gmail.com