ACI-, SRT- and REG-expressions shall get precompiled

[westram]

Advantage: better performance (esp. for NDS, search tool, modify fields)

General concept:

All these expressions

• take an input string + an execution environment and
• produce an output string.

All sub-commands of a "normal ACI expression" do the same, with the difference, that they take/produce multiple I/O-streams (=strings).

Precompiled expression:

consists of

• name (or expression or both)
• function-pointer
• list of parameters (type: string or precompiled sub-expression)
  • type is only known by function
    (e.g. arguments to binary operators like plus are ACI-expressions)
    ⇒ function needs permission to convert (string→precompiled expression)

Execution environment:

existing environment:

• the given item (e.g. species; optional)
• the name of the current (optional)
• database (gb_main)
• execution state (error)
• trace mode

Optional data might be expected by some ACI-commands (/item).

Shall also store caller-defined data (see #756).

Related data:

• current input- and output-streams

Notes:

• REG-expressions are already able to get precompiled.
  There are 2 types of REG-expressions:
  • REG-match (e.g. /^hi.*light/[flag]) - precompile available
  • REG-replace (e.g. /old/new/[flag]) - precompile needs to get separated from execution
• SRT - no precompile available yet; maybe only split into single replace-ops
• ACI
  • implicit (unnamed) commands:
    • queue (e.g. |"[";dd;"]"; each part of queue applied to all input-streams)
    • text (e.g. "["; ignores all input streams, writes one fixed output stream)
    • pipe (e.g. |len|minus(5); first part of pipe applied to all input-streams, other parts applied to output-streams of preceding part)