src/Tools/VSCode/extension/src/symbol.ts

 /* ASCII characters */
 
 export type Symbol = string
 
 export function is_char(s: Symbol): boolean
-{ return s.length == 1 }
+{ return s.length === 1 }
 
 export function is_ascii_letter(s: Symbol): boolean
 { return is_char(s) && "A" <= s && s <= "Z" || "a" <= s && s <= "z" }
 
 export function is_ascii_digit(s: Symbol): boolean
 { return is_char(s) && "0" <= s && s <= "9" }
 
 export function is_ascii_quasi(s: Symbol): boolean
-{ return s == "_" || s == "'" }
+{ return s === "_" || s === "'" }
 
 export function is_ascii_letdig(s: Symbol): boolean
 { return is_ascii_letter(s) || is_ascii_digit(s) || is_ascii_quasi(s) }
 
 export function is_ascii_identifier(s: Symbol): boolean