# Functions
ParseDir calls ParseFile for all files with names ending in ".go" in the directory specified by path and returns a map of package name -> package AST with all the packages found.
ParseExpr is a convenience function for obtaining the AST of an expression x.
ParseExprFrom is a convenience function for parsing an expression.
ParseFile parses the source code of a single Go source file and returns the corresponding ast.File node.
# Constants
report all errors (not just the first 10 on different lines).
report declaration errors.
stop parsing after import declarations.
stop parsing after package clause.
parse comments and add them to AST.
same as AllErrors, for backward-compatibility.
print a trace of parsed productions.
# Type aliases
A Mode value is a set of flags (or 0).