ion/src/compiler/preprocessor.coffee

ion language ========================

common = require './common'

getSpace = (size) ->
    result = []
    result.push " " for i in [0...size]
    result.join ""

exports.isMarkdownCommented = (source) -> /(\n|^)[^\s\n][^\n]*\n(\s*\n)+\s+[^\s\n]/.test source

exports.fixSourceLocation = fixSourceLocation = (location, sourceMapping, source) ->
    if not location.fixed
        location.fixed = true
        location.line = sourceMapping[location.line - 1] + 1
        location.column += sourceMapping.columnOffset ? 0
        location.source ?= source
exports.fixSourceLocations = fixSourceLocations = (program, sourceMapping, source) ->
    require('./traverseAst').traverse program, (node) ->
        if node.loc?.start?
            fixSourceLocation node.loc.start, sourceMapping, source
        if node.loc?.end?
            fixSourceLocation node.loc.end, sourceMapping, source
    return program
exports.preprocess = preprocess = (source, sourceMapping) ->
    isMarkdownCommented = false # exports.isMarkdownCommented source
    baseIndent = if isMarkdownCommented then 1 else 0
    totalIndent = 0
    indentStack = []
    lines = common.splitLines source
    nonCommentCount = 0
    writeLine = (line, inputIndex) ->
        if inputIndex?
            sourceMapping?[output.length] = inputIndex
        trimmed = line.trim()
        if trimmed.length > 0 and line.trim()[0] isnt '#'
            nonCommentCount++
        output.push line
    outdent = (inputIndex) ->
        indentStack.pop()
        totalIndent = indentStack[indentStack.length - 1] ? 0
        if totalIndent >= baseIndent
            writeLine getSpace(totalIndent) + common.outdentToken, inputIndex
    output = []

    for line, index in lines
        indent = common.getIndent line
        isEmpty = line.trim().length is 0
        if not isEmpty
            if indent > totalIndent
                if totalIndent >= baseIndent
                    writeLine getSpace(totalIndent) + common.indentToken, index
                totalIndent = indent
                indentStack.push indent
            else
                while indent < totalIndent
                    outdent index

        comment = isMarkdownCommented and indent is 0 and not isEmpty
        if not comment
            writeLine line, index
    # push any remaining outdents
    while indentStack.length > 0
        outdent lines.length

    if nonCommentCount is 0
        return ""
    else
        return common.unindentString common.joinLines(output), sourceMapping

# sample = """

# This is a comment.
# Anything left justified is a comment.

#     Person
#         name: "Alpha"
#         age: 40
#         children:
#             Person
#                 name: "Beta"
#                 age: 1
#             Person

#                 name: "Charlie"

#                 age: 2
#                 description: ""
#                         This is just a
#                     sample indented multiline
#                     string literal.
# """
# expectedResult = """


# Person
# {{{{
#     name: "Alpha"
#     age: 40
#     children:
#     {{{{
#         Person
#         {{{{
#             name: "Beta"
#             age: 1
#         }}}}
#         Person

#         {{{{
#             name: "Charlie"

#             age: 2
#             description: ""
#             {{{{
#                     This is just a
#             }}}}
#                 sample indented multiline
#             {{{{
#                 string literal.
#             }}}}
#         }}}}
#     }}}}
# }}}}
# """
# exports.test = ->
#     sourceMapping = {}
#     # first try with the markdown commented sample.
#     result = preprocess sample, sourceMapping
#     if result != expectedResult
#         console.log 'result---------------------------------'
#         console.log result
#         console.log 'expected-------------------------------'
#         console.log expectedResult
#         throw new Error "Preprocessor result not expected result."
#     if JSON.stringify(sourceMapping) != '{"0":0,"1":3,"2":4,"3":5,"4":5,"5":6,"6":7,"7":8,"8":8,"9":9,"10":9,"11":10,"12":11,"13":11,"14":12,"15":13,"16":13,"17":14,"18":15,"19":16,"20":17,"21":17,"22":18,"23":18,"24":19,"25":19,"26":20,"27":20,"28":20,"29":20,"columnOffset":4}'
#         throw new Error "Unexpected line mapping: " + JSON.stringify sourceMapping